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Frost Protection for Gardens and Landscapes
93 Plays1 year ago
Join us as we discuss practices for safeguarding your beloved garden and landscape against the harshness of frost. We will share tips on using mulch, cloches, and specially designed fabrics to insulate plants, as well as the importance of strategic watering and plant selection for frost resistance. Tune in to discover how to keep your green oasis thriving through the chilliest times.
Average Last Frost Dates for Kentucky
Simple Calculations for Small Drip Irrigation Systems
Questions/Comments/Feedback/Suggestions for Topics: hortculturepodcast@l.uky.edu
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Transcript
Welcome to Hort Culture
00:00:02
Speaker
Welcome to Hort Culture, where a group of extension professionals and plant people talk about the business, production, and joy of planting seeds and helping them grow. Join us as we explore the culture of horticulture. Hey, everybody. Hope you all are doing well today.
Casual Catch-Up
00:00:20
Speaker
How's, uh, how are the bald boys? How's Ray? How you guys feeling? I'm chilly. Chilly. Froggy. Chilly. Froggy. Brett.
00:00:30
Speaker
I'm doing pretty good.
Bonsai Repotting Excitement
00:00:32
Speaker
We're in the middle of bonsai replanting season or repotting season, I should say. So doing some of that, which is pretty fun. I love doing all that kind of stuff when I get to bump up something. It's all exciting. I'm like, you've made it to the next stage.
00:00:53
Speaker
So it's all exciting out there. Well, it is when we're recording mid-March and cold outside, back to cold from being warm.
Frost Protection in Kentucky
00:01:02
Speaker
And before we get started, we're talking about frost protection today, which seems very timely and you know, you can use it later, but it's very timely for us because we're having a lot of cold nights sneaking back up on us right now, which isn't super unusual for our area of Kentucky, but
00:01:20
Speaker
I just want to remind everybody who may have been outside enjoying maybe some warmth lately. I know a lot of places in the country have been having some warm spring days and if you've been out and seen maybe a disaster in your perennials or in your garden or whatever that is, it is okay and you can always start over and sometimes that sucks. And mostly I'm telling myself this right now, but if this is helping any of you, I hope it is.
00:01:48
Speaker
What can you can you characterize the disaster that you're
Gardening Disaster: Clover Takeover
00:01:52
Speaker
talking? Personally, my personal disaster is that in some of my perennial rows, uh, I have, you know, 50 foot long rows of one or two species of something. And these are outdoor, not outdoor perennial beds. Yep. And I have some clover that has taken over.
00:02:08
Speaker
And I now feel more for those people who come into my office sometimes and they go, I swear it wasn't like this. Like I didn't let it get out of control. I just came out one day and it looked like this. And I feel that for them because that's the way it feels for me. And I have come to the realization that I'm probably going to have to just terminate the plants in those rows.
00:02:30
Speaker
and start scratch, start over a little bit. They're just, I will not be able to save them. They cannot be saved. I'm pushing them off the door from the Titanic, like they're going. You're terminating them. I'm terminating them. Come with me if you want to die. That was hard. That hurt me. Those are young babies and I put them in and they were some of the first plants that went on my farm.
00:02:59
Speaker
It'll be cheaper for me to buy new plants than to try and save them and weave that row because clover is just unbearable. But anyways, all that to say that if you are having something that maybe didn't work out the way you thought it would or something like that has happened, it's going to be okay. And that's the beauty of mother nature is every year she gives us a
Importance of Frost Protection
00:03:18
Speaker
new start. And so, um, you know, that's me getting in my fields today. So welcome to the podcast.
00:03:25
Speaker
Wait a minute. Terminating was you getting into your fields? Yeah. I'm terminating. I'm going to kill my children. I'm terminating my children. That's a very sad day for me. But sometimes you just got to, just got to cut the court, you know, you just got to. Well, and there is a certain, like, if you try to keep keeping something going, it ends up costing you way more time and stress and heartbreak in the longterm. And there really is a point of,
00:03:55
Speaker
Well, let's just rip the band-aid off. So I feel for you, but glad that you're able to make some peace with it. I mean, I'm not there yet, but I'm hoping to get there soon. That was me speaking it into existence. Into fruition, thank you. I need those good vibes. So anyways, maybe that's happened to you with frost protection and you go, oh crap, I should have covered that. Has anybody else on the podcast come out the next morning and go, oh no, I didn't cover.
00:04:24
Speaker
You didn't know it was getting cold or you forgot or something. Yep. So we're going to talk to you a little bit about that today and maybe about deciding when it's.
00:04:34
Speaker
when that plant does need to be roped, maybe it's a little too late or ways to keep it from happening. So, you know, you don't have any of those moments that we have all experience of the, you know, oh crap. So.
Kentucky's Temperature Swings
00:04:49
Speaker
Yeah, I think, I think, yeah, there is, there's temperature ranges and we're in that, we're in a place where, you know, obviously any temperate place has these swings, but you know, Kentucky seems to be one of those places that's truly blessed with the,
00:05:04
Speaker
All my plants thought that we were raring and ready to go for summer and this past week and now they have little tiny tender leaves on them that. We don't have temperature swings we have temperature merry-go-rounds. Yeah it was for reference it was over 70 at my house my.
00:05:27
Speaker
My weather station was reading, it was like 73 at the house, full sun, you know, beautiful day. And then four days later, our low is 28 and then going to be 24, I think tonight. So we'll see.
00:05:42
Speaker
Just for reference on when we say it was warm, we really mean it.
What is 'Redbud Winter'?
00:05:47
Speaker
Yeah. Well, on that note, just to give a quick shout out to Sean Wright, I saw on his one of his social media, he introduced me to a term that I have a sinking suspicion Ray is familiar with, but the rest of you may be not because it's very folksy and Ray always has an angle on or has a
00:06:04
Speaker
Ray was there when it was first mentioned. Yeah. In the beginning. Ray the vampire who looks younger than me but is 431 years old this May. 432 this year. Yeah, 432 this year. Sorry, I lost, yeah, leap year. Missed a year. But he said that he had seen a redbud starting to flower out and he said that I was close enough he's going to go ahead and call it that it's a redbud winter.
00:06:32
Speaker
there are these other terms like dogwood winter and I can't remember some of the other ones but it's this this period of time where like you have this little mini seasonal micro seasonal singularity as I came to found out that the meteorological term for it where you have this little mini winter thing and then I guess it's around the time that the red buds bloom and that
00:06:56
Speaker
that there were a lot of producers who back in the day would say, don't plant anything that's tender until the dogwoods have fully flowered as a reference point.
Historical Planting Indicators
00:07:06
Speaker
And so, yeah, if you're looking for a little rabbit, historical rabbit hole, farmer's almanac style rabbit hole to go down.
00:07:14
Speaker
Dogwood winter, Redbud winter, and there were a couple other ones too. Blackberry winter. Yeah, Blackberry winter. See, I knew this guy. Go ahead, sorry. I was going to say I took a picture of, I was on Welch Mountain in Madison County yesterday and I took a picture of a Redbud and I was thinking about Redbud winter.
00:07:33
Speaker
And it seems like different populations back in the day before information was so easy and readily available in your hand, they had to have some kind of a way of remembering seasons and watching out for these historic temperature dips. So if you look into the folklore behind like Blackberry winter and Dogwood winter and Red Bud winter, that was sort of a cautionary tale to beware.
00:07:59
Speaker
planting too early when you saw these indicators, uh, but it was a, just a practical way to remind them, yes, this may be blooming, but this is not the time to plant. It was just a very visual reminder of. So the red bud blooms are sort of a, uh, false, or, you know, if you're taking that as an indicator, it's actually.
00:08:17
Speaker
a warning of sorts. It feels like spring, it is not spring, or I know it may be meteorological spring, but it is not planting season yet. That just tends to hold your horses, basically. Well, I thought that was interesting
Microclimates and Planting Dates
00:08:29
Speaker
too. I mean, it's interesting too, because one of the things we talk about related to this frost protection and planting dates and all that kind of stuff is
00:08:36
Speaker
like the aspects of microclimate and particularly in a place like, in places like East Kentucky or in the foothills where you could have these crazy, crazy microclimate differences and they can even be consistent year to year or sometimes they're affected more heavily one way or the other. And it was one of those challenges when we were trying to come out with, you know, planting date related stuff for, you know, high tunnels or something like that where people are like, well, in my area, like I'm on this South facing slope
00:09:06
Speaker
And for me, all the dates are way earlier than that. And it's like, yeah, in an extension, we give you a conservative thing to base it off of. But in your microclimate, things can be interesting and different.
Frost vs. Freeze: What's the Difference?
00:09:16
Speaker
And to that point, like you have this botanical barometer sort of spring and the flow of seasons. And the Blackberry thing, I think, is because the Blackberries need a little snap of cold before they start to grow. And so it's
00:09:39
Speaker
That's cool. Ray probably invented it 430 some days ago. Ray and his crew were like, we're going to go with Red Bud. We love Blackberry, so heck with Blueberry winter, we're going Blackberry winter. Exactly. That's the reason, folks. It truly is. The people you were feuding with up the street, the Blueberry people, you all won. In Central Kentucky, there's some good ones. I know here, one that I didn't use a lot as an indicator, but a lot of folks that I've ran into in Central Kentucky use the blooming of the Forsythia.
00:09:55
Speaker
Yeah, it was, it was just really cool. I had a feeling, were you all familiar other than Ray familiar with those terms before? Yeah.
00:10:09
Speaker
as an indicator and another date that they
DIY Frost Protection Tips
00:10:12
Speaker
use as a practical indicator I think we mentioned before we officially started recording today and then I never ran into and that was well it's not Derby Day yet it's not time to plant and so that led me to today while we were talking to go look up Derby Day which is May the 4th which coincides with
00:10:30
Speaker
the exact week that you should plant your average garden crops in Kentucky and things like tomato and things, as far as lining up with frost-free dates. So Central Kentucky was always the first, it's always the first Saturday in May. And that's in Central Kentucky that corresponds very well with the safe frost, the average historical safe frost-free date. So yeah, I hadn't ran into this day. Like if they just average the last 30 years or 1991 to 2020,
00:10:59
Speaker
The average last frost date is May 1st to May 10th. So it's still consistent. It's still there.
00:11:05
Speaker
Yeah. And that's the Kentucky Derby, which is a thoroughbred race. Uh, that's one of the triple crown races in one of the major events, uh, as far as in the city of Louisville for those of us, for those listeners outside of the Kentucky, uh, area. It's kind of a big deal here. It's unlike CBS or something, you know, it's one of those listen, Justin Timberlake was there last year. So it's kind of a big deal. So they finally say no more.
00:11:35
Speaker
But but but but the part of the the dynamic of this time of year is that there are certain things like perennials or other things you may have in that unfortunately can't take a look at the red buds and say, Oh, not yet back in the ground or or back inside the stem. And so there might be some methods we need to do to protect those things. Right. Right. Yeah. Because, you know, you have a neighbor that you're in a contest with the first tomato.
00:12:05
Speaker
And it's a big deal. You want to be the first or if you're a commercial producer, you know, there's many different, you know, monetary reasons why you may want that early harvest of tomatoes or whatever. Yeah. They run the edge there.
00:12:19
Speaker
Alexis and I have a competition of who can have the first peony and how many years I don't even remember the record on that. You really did. You really went there. If you're going to make me pull out my hoops and put plastic over my peonies to have this competition, I don't want to, but I will. OK, I will build. I will build a fully lit greenhouse and I will have your round.
00:12:46
Speaker
She will establish a city of 300,000 people around her to generate a dome. Yes, yes. Here we come. We're about to blow this baby up. Her face says she's serious. Her eyes, yeah. The fire behind those eyes that I just generated through. I might add, I literally just put them in the ground and they happen to come up early, but I like to
00:13:15
Speaker
wear it as a marker of skill and other things. My choral charm peonies are like a foot tall okay so I don't want to hear it. I know only 18 inches so that I mean oh yeah oh wait a minute that's over a foot. 18 inches is more than a foot. Oh man Brett yeah.
00:13:36
Speaker
Brad, I was curious, I know that you have a microclimate there in Fayette County, but just really curious and it kind of goes along with the topic today. Are you like south or do you have a southern exposure or western exposure? I know that tends to be the areas that really get about a week's
Wire Hoops and Row Covers
00:13:53
Speaker
jump.
00:13:53
Speaker
Yep. Southwest is the major, our backyard basically by about 11 o'clock, we're getting full sun and then we get full sun all the way till I'll just sun down. Amazing. What a difference that makes. And you know, we can see it in our home lawns. One of our previous podcasts, we were talking about home lawns, but the back of my yard is, you know, Southern kind of Southwestern exposure, but the front is shaded.
00:14:18
Speaker
And the backyard is always two weeks ahead of the front just because of temperature and sun exposure. It's actually one of the reasons we got this house is because it's the one of the few that we looked at in this neighborhood that had that kind of exposure and that didn't have trees in our backyard, at least on the southern side, nor in the yard to the south of us.
00:14:45
Speaker
It's one of, because we were back then, you know, planning on gardening and doing all the other plant stuff. And that was one of the things that I, every time we would go with the realtor, I would pull out a compass and they were like, are you from a sort of cartographer? It's like, no, no, no, no. I'm taking magnetic readings and seeing if the CIA can read my thoughts and check it. I'm checking the vibe.
00:15:06
Speaker
It was one of those things in the contract we signed that I had to have a good soil report. Otherwise, I'm not buying it. That was our out. Even with that sun exposure in the bonsai world, there's this joke about the Midwest shuffle, which is basically pulling your plants in and out and out of doors and inside.
00:15:28
Speaker
And so that's cool because they're in pots. All my trees are in pots. So they're able, I'm able to pick them up and move them inside. But if I, if I weren't able to do that, what kind of things do you all think? Like what, how do we want to frame this conversation about frost protection? How do we, what are some of the tools? We start with dates, which one of you guys mentioned dates already frost free dates and where to find those at?
00:15:51
Speaker
There's a really good resource so good that I wish I could kind of recreate it but I've been struggling to do that but just to plug this site plantmaps.com now that's if you don't know your local botanical indicators and can't say hey there's the dogwood blooming if you're just looking for straight dates
00:16:11
Speaker
This site has a map called, and we'll put a link in the show notes, the average last frost dates for Kentucky. So it's specifically for spring, and it's based on averages from the 30 year, quote unquote, normals from...
00:16:27
Speaker
the NOAA so 1991 to 2020 so very recent and they range kind of all over the place though most of the state is as we said kind of May 1st May 10th is when it's expected if you go into like the southwestern part of the state that's more April 21st to April 30th and then far into the eastern part most of the east is May 11th May 20th but there are these little pockets due to that kind of
00:16:55
Speaker
the topography and all these little microclimates or mesoclimates of May 21st and May 31st, even as late as June 11th to June 20th.
Using Plastic and Frost Blankets
00:17:07
Speaker
But most of us, May 1st to May 10th. And we'll put a link for that so you can kind of look up your area. And it's also modeled so it's not a predictor. It's basically telling you the history of what has kind of happened in the region in the last 30 years.
00:17:25
Speaker
Well, and so we're, we're a little ways off from that. Yes. Yeah. So we got six, seven weeks to go. Some people two months ago, right? Yeah. So we're on this carousel between now and then. But how many of you guys see, um, plants in a local garden center that are available well, well before the optimum dates? Yeah. They're stocked up and ready to go already kind of near, near us. And there's a lot of stuff.
00:17:50
Speaker
So be careful, watch your dates and if all else fails just go by those dates that Josh just threw out to you because they are based on lots and lots of data, 30 years worth in the case of the source Josh just mentioned. Those are good, they're not perfect because you can always have
00:18:07
Speaker
a late frost that pops up and that's really what drives phone calls to our local offices is that you know let's say you know frost free date was supposed to be May the 5th or 7th and then all of a sudden you have a frost predicted for May the 15th then what that's the phone calls that we get is when we have one of those odd out of the ordinary
00:18:30
Speaker
frost events that's coming in because there's a lot of factors involved on what's going to get damaged. And I guess that's the discussion today. What can we do if you've already got plants in the ground or you have tender landscape plants at a broken dormancy and they've started growth. So that's kind of the conversation today, isn't it?
00:18:48
Speaker
Yeah, and I think maybe something you will we could talk a little bit about temperatures and we can also talk we talked we hinted at the micro climate thing. But like one of the things that I know, for instance, I mentioned, you know, the the one side of our house that is south facing. So it's a brick house.
00:19:07
Speaker
Yeah, it's a big house. Big house. That bed where those plants stay and the surrounding area around the soil temperature stays predictably 10 degrees warmer than it does just about anywhere else. Yeah, the heat sink. Yeah. And that is something to consider. But as far as temperatures, the idea of the frost versus the freeze, those types of things, what ranges are you all
00:19:35
Speaker
You look at it and you're worried about it.
00:19:38
Speaker
Well, a freeze is both temperature and duration. Freeze is the more, frost can lead to a freeze, but just because you have a lot frost, that may not necessarily mean you have the duration of temperature. It doesn't stay cold enough long enough to do the types of damage that really worry us. Whereas a freeze is the more serious of the events to me. I know you're working kind of mixing words here. A frost doesn't necessarily wipe everything out, but a hard freeze can.
00:20:06
Speaker
Yeah, the temperature, I'll go ahead and throw out the temperatures that I kind of think of as like, ooh, danger zone and stuff is kind of for a frost, I think between 33 and 31, kind of right around that 32 range. Though even a few degrees above that can be cause for, you know, keeping an eye on things and that a freeze or a hard frost is kind of more below that, like kind of 26 to 31 degrees.
00:20:36
Speaker
Yeah, there's a point to where you really can't if you're a homeowner. I mean, there's a few more options available, limited options available to commercial producers. But if you're a homeowner, there's a point to where frost blankets will not work. And I know Alexis may have some information later on with some coverings for plants and the ranges that they can provide you some protection. But there's a point to where no matter what you do, if we have a 22 degree nod that has a little bit of duration to it,
00:21:03
Speaker
There's not a lot you can do. You're just going to have some damage that you're going to prune out later and hope that it didn't kill all of your flower buds or new growth. And you won't know that until the growth starts later on in the spring. So if you do have a freeze event, you're basically just waiting. You're not pruning right then. You're just waiting till later in the season after growth starts and you can take a better assessment. And then you can go in and do some cleanup, some pruning out of dead stubs and stuff.
00:21:32
Speaker
But yeah, there's a point to where you can't do a lot as a homeowner, but there are some options available. If you are a homeowner, if you have a tender tomato or landscape plant out there. The worst thing to do is that when you do get some maybe some cold damage on something and
00:21:50
Speaker
You're like, there's no way it's coming back from this or it looks really weird. And then you cut it out that day or the next day, usually that day, but really it would have come out with a bit. I always remind myself like plants want to live. So like give them a chance to do that. And usually with freeze damage or frost damage, 24 hours, as long as you're kind of gonna get back above freezing, you can tell what's gonna make it and what's not.
00:22:18
Speaker
For perennials that can be really hard because usually they're pretty in a much a little bit more of a dormant state in there. Some are just more resilient than others. But I know I've seen my I've seen snapdragons I think.
Resilient Cold-Loving Plants
00:22:30
Speaker
snapback from just the ultimate brink of death. And I'm like, how? How? I tried to call them snapback dragons. Snapback dragons. And also for some things, even annuals, again, I'm going to go back to snapdragons, but I've seen this on some other cold loving annuals specifically. We talk a lot about
00:22:50
Speaker
frost dates for those summer things, but I know a lot of people who listen to this podcast are growing things in the cold. So if you're doing veggies, you may be doing kale or spinach or something like that right now. There's flower farmers that have had stuff out all winter and these warm
00:23:06
Speaker
Times that we have really flush growth and then we get these cold periods which is an ideal but I've seen you know, snapdragons come back from the root because they spend all winter putting down really good roots and so you don't necessarily want to call that bed a wash until you kind of wait to see
00:23:22
Speaker
In some cases, it's not worth the extra time it's going to take for them to come back. But a lot of the times, they'll come back and flush and still be a profitable crop. So give those plants some time to recuperate, I think. Yeah. One of the take-homes you said from that is that if you get frost damage, I know it doesn't look good and you want things to look good because then you feel better about them.
00:23:48
Speaker
But like imagine that you like cut your finger and you were like, oh, that looks really bad. So I'm going to cut all the area out around that and remove it like you're opening it and creating a bigger wound and you're not allowing the plant itself to compartmentalize and heal because a plant that's one of the cool things about perennials. A lot of perennials, especially woody perennials, is they have this process that they like of compartmentalization where they will strategically die back to an area like particularly like a node or something like that where
00:24:17
Speaker
They they the plant kind of knows like that part is done but give me a chance because it's going to take a little while for me to cut off resources to that area to then drop that branch or drop that part of that branch and
00:24:30
Speaker
So that was the thing I was taking from what you were saying, Alexis, is if you get that frost damage, in addition to just letting the plant see, make sure it may make it, but also don't go out and preemptively think you're helping the plant out by removing that tissue because you're just giving it a big old cut. I mean, if it's like, you know, it was green and now it's black, that's different, right? You know, cut out that black area because it will hold on to disease, but try not to get into that green too much, right?
00:24:55
Speaker
healthy tissue is compartmentalizing and walling off that dead area. So that's... Well, yeah. And if you give it a little bit of time, it starts to become obvious where it's making that compartmentalization and then you can kind of conduct your pruning without interfering.
00:25:13
Speaker
Yeah. So there's no harm done to wait and prune after the tree has leafed out or the plant has leafed out. And in fact, waiting a little bit probably is a good idea in that case. Yeah. Just for a better assessment if for no other reason. And sometimes when you go pruning on a plant, it can further de-harden the plant or wake the plant up and cause early growth that will then be further damage. So there's lots of good reasons to just wait.
How Do Frost Blankets Work?
00:25:40
Speaker
a little give a little bit of time until all reasonable you know chance of frost is passed before you do those pruning cuts. So yeah lots of good reasons to wait on that operation but I know growing up you know we're talking about like frost protection here and I think of home gardens every spring because I would drive by
00:26:03
Speaker
I remember being very young and I'd drive by home gardens and I would see just all of these milk jugs and containers turned up kind of in gardens. People had made these makeshift sort of little mini greenhouses around there, typically tomatoes and peppers, I think.
00:26:19
Speaker
And that was pretty common back then. Any of you guys have any experiences with anything like that? And what's the word I'm looking for? It starts with a C. I can't pronounce it very well. But it's when you take the jar, though, it's like a French term. Not a cloche.
00:26:37
Speaker
Yeah, but there's actually I love those when I find those after I try to purchase them because there's sort of an antiquey sort of thing and what Alexis those are typically made out of glass and they were made with the what the purpose of going over plants and protecting them.
00:26:52
Speaker
Yeah, I really like those except for you put them over and the plant fits, but anywhere that that plant touches the glass, which is something we should talk about, anywhere that plant touches the glass will burn. We'll have frost and we'll have cold burn, right? Because that glass, what's the word I'm looking for?
00:27:11
Speaker
like it conducts the cold. So that's why a lot of the frost protection you see are going to be blankets because they don't conduct that cold as well. Ideally you're still lifting, and I think we've talked about this before, but it's been probably a year ago that we talked about this.
00:27:31
Speaker
You still want that fabric not to touch the plants, but if it does, it's not the end of the world. You might get a little bit of burn, but it doesn't conduct the same way as like a plastic or a glass does. Right.
00:27:44
Speaker
So that's why it's like it's essentially the insulation is the air and what that blanket is made out of has all those little air pockets. And the most important concept of what you're talking about Lexus to me maybe you could talk a little bit about it is the way that we connect that fabric to the ground taking advantage of like the ready the ground as a heat sink slowly releasing the stored up sunlight from the day before the week before. Just a reminder that
00:28:12
Speaker
99% of what that blanket is for is to trap heat coming out of the soil. So when you see the people who have thrown their bedsheets over top of their dogwood tree and it's just like a ghost hanging out there. The edges aren't touching the ground. The edges aren't touching the ground. And again, no judgment. I understand just kind of wanting to just do something
00:28:34
Speaker
just to try, but ultimately the chances of that being successful is very, very small in protecting. It depends on what the temperature is, but the goal of frost blankets or even like, again, even if you were using a sheet, that's fine.
00:28:52
Speaker
is that it's touching the ground and it's trapping the heat that is coming up out of the soil. That's what you want and to create this kind of air bubble around those plants. So it's really important. And if you're growing crops, you know, be prepared for that. And you ideally, like we said earlier, don't want that blanket touching the plant. In some cases it can't be helped. Like I covered Rose last night and I've got one row that is just, you know, it's big and happy and they're bachelor buttons and they're, they,
00:29:21
Speaker
are huge right now, but they can also tolerate like really cold temperatures. So I wasn't too worried about covering them with a blanket and it touching them because they don't, they don't care and they're very vigorous. So they'll come back if they don't. So, but most of the time you want to try and keep that pocket of air, a big bubble around those plants.
00:29:41
Speaker
I notice a lot of commercial producers and they're using the term correctly. They talk about floating row covers because they don't have any kind of scaffolding or framework because they're just too large and they'll just pull those row covers over strawberries for instance. That's a good example and it was very interesting that I have one grower that grows
Humidity and Frost Protection
00:30:03
Speaker
a specific type of cover crop and lets it grow up to a certain height and the cover crop actually provides the float
00:30:10
Speaker
for the road covers and it holds it over the off of the strawberry so it works awesome but when they talk about floating road covers they literally just they just kind of pull them across yes ideally if they had some kind of framework to hold those off a bit more
00:30:25
Speaker
That would be great. But commercial producers on large scales don't often have that luxury. But for homeowners, yeah, that's a great point. If you can do it, you know, do that. And I have seen what raised beds with kind of PVC kind of ran into PVC, yes, hoops made onto raised beds. And that works very well on raised beds. We're talking about like eight by 10 boards on the side, eight by eight, eight by tens.
00:30:52
Speaker
you can put hoops on there and then just kind of drape the cover over to take advantage of that heat retention. So it's pretty cool. If you can do it, do that. You talked about, oh, go ahead. I was gonna say, you can go get, you know, if you're, I buy, I go buy like hundred things of these like short little wire hoops that I can put in the ground and that are, you know, only about a foot and a half high.
00:31:16
Speaker
Is that what they're made for Alexis? Right. Yeah. They're made for kind of holding or, you know, sometimes some shade cloth, but the, but those low crops, you can also use them for insect netting, blah, blah, blah. But there are these short ones, but before I needed, you know, hundreds at a time, you can go and buy, I think it's 10 gauge. I had to look that up. I think it's 10 gauge wire. You can buy on like a, for pretty cheap at like a Lowe's Home Depot type store and you buy it on like a,
00:31:45
Speaker
What's I'm blanking a spool, a spool. Yeah. You buy it in like a spool. It's just long and you can just cut your wires to length. So if you have a four foot bed, you know.
00:31:55
Speaker
two foot bed, whatever, and you just cut it and bend it. And I'll be honest, I still use those ones that they are ugliest sin, which bothers me a little bit. But when I run out of my good ones, I'll use them and they do the job. They just look bad because I stretched, I did them all by hand instead of putting them on something to stretch them. But anyways, you can do that as well. And that's a, I was like 20 bucks and I probably made
00:32:18
Speaker
50 hoops or something from it. And you're talking about a material that is, you guys are talking about a material that's custom designed for this very purpose. It's not like taking a bed sheet, which can work in a pinch, but we're talking about material that is specifically designed to have thermal qualities and different kinds of qualities. I guess this material, this spun bond, I call it, Brett, you had another word for it.
00:32:43
Speaker
What did you call it? A frost blanket. Yeah. But this type of material comes in different temperature ratings, too, doesn't it, Alexis?
00:32:52
Speaker
Yeah. And so some of them you're just using, some of them are almost more for insect netting. I know that not, there is specific insect netting, but really that light covered one. I know that I think the farm would use that for like their earlier season stuff that could handle it. Before the, the fancier new, you know, micro mesh for insects came out, the lightest weight of row cover was kind of the gold standard for a lot of
00:33:19
Speaker
So in organic production systems, particularly you can't use some of the insecticides that help things like cucumber beetles make it, I'm sorry, help things like cucumbers make it through the onslaught of cucumber beetles that then give them bacterial wilt and melt your plants into the ground. And so the, if you can't, if you can't spray, then you, but you, you can exclude. So you can put that on and it would literally be like a very thin blanket.
00:33:44
Speaker
But it's the same type, it's just a different thickness, sort of like the difference between a light windbreaker versus a heavy winter coat.
00:33:55
Speaker
They're all coats of a sort, but, uh, yeah, that, that we would, we would use those pretty regularly and you can, you can see through it almost. It's so thin and the thicker stuff you can't really see through. Ray, what was the, you had the temperature like kind of, you know, differentiate like how much, you know, a lightweight versus a heaviest weight. Like they say there are some temperature.
00:34:15
Speaker
Yeah, some basic qualities. I mean, take this with a grain of salt because everyone's situation is a little bit different, but just for general purposes and guidelines is that the half ounce per yard, that's typically you'll see some number on this spunbond or floating row cover top fabric from gardener's supply places or commercial supply places. But if you get something that's sort of a half an ounce per square yard, it's going to say like a two to three degrees temperature benefit.
00:34:45
Speaker
When you get into the heavier stuff on the very upper end, it's anywhere from 6 to 10 degrees protection, temperature protection. I have never personally used a fabric that could hold like 8 to 10 degrees, but in theory they make that. It's much heavier material, but you can get it anywhere from 2 degrees protection up to 10 in theory.
00:35:13
Speaker
The heavier stuff obviously will trap more heat, so you have to give consideration there as far as are you going to have to take it off if the temperature and sun comes out and the temperature rises the next day. Whereas the lightweight fabric is just that. It's lighter in weight. It doesn't trap any buildup of heat, typically much at all. So you can leave that on in some cases.
00:35:35
Speaker
Yeah, that's sort of the temperature range anywhere from 2 to 10 degrees protection. And not only the way that it traps heat, but also the light penetration.
00:35:47
Speaker
In general, if you're trying to grow things in an off season, you're using frost blankets. If you're using row covers as part of your strategy, you need to build in on, off, on, off, on, off cycles. All the time. Yeah, it's just nonstop. Yeah. And that is where it's just an example of where like, I have been, you know, I've been able to be on a, I've been able to be on a number of different farms and I've been able to see a bunch of different systems where
00:36:17
Speaker
they figure out a way to make that process as painless as possible. Because like, you know, it could be as simple, like if you ever, you know, put sheets, you know, made a bed with someone, you get on one side and get on the other and you just take and pull the sheet up and tuck it and blah, blah, blah, like that. It could be as simple as that, but I've seen ones where people will actually take and set a post on either end and they will run cable, like a tension cable from one post to the other to create at about, I don't know,
00:36:46
Speaker
18 to 24 inches off the ground. And there's a series of those that runs in parallel with all the beds. And that serves as this sort of like this surface on which you can pull the row cover. And so you just get a person on either side and you walk the full length of the tunnel and you pull a big sheet over all of it.
00:37:07
Speaker
We haven't talked about this yet, but there are, you do often use row cover even inside of a high tunnel. And if you have 15 high tunnels that are a hundred feet long, covering those would be a nightmare. Yeah. If you didn't have some kind of a system for, for doing that efficiently. And so the on off, on off thing, it's kind of unavoidable in most cases, I think.
00:37:31
Speaker
depending on how much you're dealing with. Yeah, winter farming is not lazy farming or winter gardening is not at all lazy gardening. In fact, it can be more frustrating because you're most of the time not actually harvesting anything or all you're doing is the hard work. You're not getting anything yet.
00:37:50
Speaker
So yeah, that can be rough.
Wind Protection and Plant Resilience
00:37:52
Speaker
The other thing to keep in mind when you're, when you're doing that is not only light, which is a really big one, but also humidity. And so sometimes, sometimes the temperature says like that you could leave those blankets on. Like I have some lighter blankets that in my really cold hardy stuff, I'll use just if it's going to be in the twenties or, you know, if it's going to be really windy because
00:38:17
Speaker
I think for me blankets, at least on my super cold hardy stuff, I want them for wind protection because what wind will desiccate those leaves. And so I'm using them more for the wind and less for the cold, even though like they kind of go together. But anyway, so a lot of the times I could take those blankets off.
00:38:35
Speaker
during the day. But I could also leave them on. It's not going to be that hot. Maybe it's overcast. They'll be fine. But I'll choose to take them off anyways because the humidity builds up. And this time of year, even though it's kind of cool, that extra humidity, a little bit of extra warmth, and that protection is great for fungal growth. So, you know, botrytis and things like that will form. So you really want to reduce that humidity during cooler periods of time. So
00:39:03
Speaker
Yeah, that can be a big one. Humidity is a double-edged sword, Alexis, to me. Because I was always afraid growing up and having some crops of clear knots with low humidity. Because if you don't have humidity, that means a greater loss of temperature during the night. That's why in the desert, it'll be over 100 degrees during the day and 40 degrees at night, the low humidity. So yeah, I have a love-hate relationship with humidity.
00:39:29
Speaker
with just general humidity when I'm looking at the temperature. That's another factor that I look at is not only the temperature, but the humidity. If there's some humidity in the air, that will give you some protection, but the kind of humidity you're talking about is localized. It's really bad for diseases, but yeah, the low humidity clear knots are a nightmare for frost protection.
00:39:51
Speaker
The wind thing you mentioned I think is one of the things that is massively misunderstood in general within controlled environment agriculture too. And I think it's, I mean, and even if, even in addition to the drying desiccating effect too, it's like, if you've ever been outside when it's really cold and you're able to step behind a windbreak, the temperature hasn't changed, but suddenly your hands aren't quite as bone chillingly painful. And I just think that that,
00:40:18
Speaker
We think about like what frost protection and season extension and all that stuff. It's almost like we think about it as the difference between being outside and being in your house. But it's like these very small incremental differences of a couple of degrees, a couple of wind chill factors or whatever that makes this huge, huge difference.
00:40:38
Speaker
Yeah. I just thought that was a really, really good point that I think is massively misunderstood that it's like, no, it's not ambiently any warmer in here inside, even inside this tunnel because the sun hasn't been out, but we are not standing in the wind right now and it is awesome. Yeah. Yeah. I really think I've noticed that.
00:40:57
Speaker
with a lot of my crops that they will withstand cold temperatures. You know, they may be hardy to zone three, but if, but we get wind that is very different than zone three, I think. And, or at least some parts, Delphinium for me is a really good example of that. It's hardy to zone four. And yet it doesn't want to grow for me and over winter for me in zone, you know, well now we're zone seven, but six. So why is that? And I think I finally figured out that it's probably wind.
00:41:26
Speaker
wind desiccation and they just, you know, they'll come up from the root system, but they're just never super great. So that's been a game changer for me, is just protecting them more from the wind and bonus if I get some heat protection from them. What about plastic as a cover?
00:41:46
Speaker
Plastic is a great cover, but it's extra important. It's up off the plants. You will get damage because that, like I said, it conducts. So plastic is great. Uh, but you do need to vent it that when you've got to be really on top of it and make sure that you're venting, if you're doing low tunnels or, you know, even just overnight, you can fry a plant really quick. Yeah. It's hard to tell the difference between freeze damage and fraud damage. If you put on plastic and it can happen, I don't know.
00:42:14
Speaker
in a very short period of time once the sun comes out.
00:42:17
Speaker
I've had my high tunnel opening and granted it collects a lot of thermal mass right when the sun is out, but it will open.
Plastic Covers: Avoid Overheating
00:42:26
Speaker
I've had it set and it'll open at like 50 degrees in the winter time and it'll open and it'll be nine degrees outside. Literally, I've had it just choose to open because I've got mine set on temperature sensors because it collects heat that much faster. So imagining that on a much smaller scale, it heats up even quicker.
00:42:49
Speaker
I think just as far as on the much smaller scale, if you're just at your house or whatever, one of the things that I've done before is, or that we do, we have some out now that are pulled back off the plants.
00:43:04
Speaker
is to get the inexpensive, extra-large garbage bags and cut them along the side to basically turn them into a big plastic sheet. And we use those as row cover for our bulbs that are coming up that are just so bright-eyed and bushy-tailed, excited for spring. And then to keep Jack Frost from crushing them, we put those on. But to your point, I'm out at
00:43:35
Speaker
Before I go to work, you know, like 8, 9 a.m. As soon as the sun is even remotely thinking about coming up, we're going to be out there to uncover everything. And Tommy's real important. You just mentioned you did that in the morning.
00:43:49
Speaker
Watch out for early, early morning because the way that the soil loses heat, it loses it over time. So that puts the coldest time of the day, usually really, really early. Right after sunrise. Yeah. Before when you're typically talking about Brett, but, uh, yeah, if you look at the, the lowest dip will be, you know, right around daybreak or before daybreak, that is when.
00:44:14
Speaker
the dip occurs because the basically that heat bank in the soil has been all used up to plead and that's the that's the dip the battery is the batteries ran out and even in commercial applications I have recommended watering the soil because that does a couple of things the main thing that that does if
00:44:34
Speaker
Under trickle irrigation is that more soil loses that heat slower? But also the conversion there's a conversion factor there of when water is cooled It releases heat and it'll do that at a ground level and that can make a difference commercially. It's real subtle Yeah, you're doing it at that point. That's one of your last line of defenses and
00:44:56
Speaker
is can plants well watered or water as, you know, you can do that up to three days, but after three days and that time of year, you know, you can have some drowning effect of plant roots. So, you know, that kind of offsets any of the positive benefits, but kind of keep that in mind. A well watered plant with moist soil does, does give off a little bit of heat. It can make a little bit of a difference.
00:45:20
Speaker
That's good to know. I didn't know that. At scale, I mean, you'll hear at scale too about people will, I was just reading an article about blueberry growers that like actually sprinkle, they'll use sprinklers on their plants to get the surface of the leaves and the roots and everything wet. Because as that, exactly what you're saying, as it evaporates, it helps to
00:45:44
Speaker
mediate the effects of the cold in the same way at the root level too. There's a couple of interesting things I learned about that in class was the, like the technical term for it is the latent heat of fusion of water. It's basically, we've talked before about how evaporation has a cooling effect, you know, that state change from liquid to gas. The opposite is true when water goes from liquid to solid, there's a little bit of heat release.
00:46:12
Speaker
And not just that, but there's also the surface of the plant, the nucleation of ice crystals forming. By irrigating, you can disrupt that a little bit. It's basically a very active and intense process because it requires a lot of water to do this. You have to water from before the frost or freeze starts all the way through.
00:46:34
Speaker
the temperatures being warm enough for the ice to melt. So it's something that's happening in really large kind of perennial farms out west. You can find lots of information about it. But it's really fascinating, kind of by yourself a couple of degrees through applying water, which to me would have seemed, I mean, it still seems counterintuitive, right? You think, why would I water something when it's about to freeze? Am I crazy? But yeah, there's some physics involved and people have
00:47:03
Speaker
lost and made and saved millions of dollars through that. Citrus especially. One of the cautionary things I saw in one of those articles is that if it is very temperature dependent, so if it's just going to be barely freezing, it can actually have the opposite effect. You should just tread carefully and do your research on that before you just launch in and start soaking all of your everything. Definitely.
00:47:30
Speaker
If you have it at a small scale, I would stick with covering things up and taking care of them that way. It's really cool. If you've got millions of dollars of avocados, you've got a consultant for this.
Plant Strategies Against Frost
00:47:44
Speaker
I know some big dahlia growers who have done it successfully. They needed one more week. They needed a harvest and stuff wasn't quite ready for October timeline. I know that some dahlia growers who are successful.
00:48:00
Speaker
who successfully did it. Even the blooms didn't get damaged, which was pretty cool. And then you have pictures of them in the morning, just covered in ice, you know, and then, you know, later in the day what that same bloom looked like. It was pretty, pretty interesting. But again, they did some pretty heavy, you know, research into that. And it was kind of like a, they didn't have anything to lose sort of thing. I mean, granted like water. Right. Like they were toast if they, no matter what. They were toast either way. So it was kind of an experiment.
00:48:28
Speaker
But yeah, it was pretty neat to see. There's actually certain varieties of wine called ice wines, where the fruit are harvested after they have frozen. So it stays on the vine as long as possible. They harvest it while it's still frozen and then make wine out of it. And it's a very sweet
00:48:51
Speaker
sweet but complex kind of like dessert wine thing. They do a lot of like up in Canada. So if you've ever seen ice wine, it's not just a gimmick, it's actually kind of a cool thing. My parents-in-law are very into wine and so they brought us some Canadian ice wine before and it's a pretty cool thing but it's kind of playing with the frost because in addition to the
00:49:14
Speaker
Starches convert. It's staying on the plant for a really long time. It also, the freezing effect has a way of really concentrating the sugars in a cool and interesting way.
00:49:25
Speaker
that kind of reminds me I mean you know we talk about all these things we try to do to help a plant stay alive but one of their own mechanisms is to kind of introduce secondary plant compounds into their own water like inside the plant water to kind of like a little natural antifreeze and and some of that is what's going on with that iced wine as well I had heard of that as well I think they do some in northern Europe but I can't remember it's
00:49:52
Speaker
specialty thing that I had forgotten completely about. That's the thing we're like, so if you remember in grade school science where you would have, you'd mix up saltwater and then you'd have regular water and you'd put them in the freezer and the saltwater wouldn't freeze and the regular water would, except plants do that with other compounds like sugars, which is one of the reasons why people talk about the best kale of the year is the kale after the frost. Right.
00:50:20
Speaker
It's a, it's a true thing. It's a real thing. It's not just something, you know, parents or somebody lied to get you to eat your kale or something like that. It's Christmas kale. Eat it. It consolidates our sugars in the leaves, which increases the sweetness and the positive flavors we associate with it. And that's pretty, pretty cool stuff. But cold, cold, cold weather dynamics with plants are crazy because they, they do all these things, these subtle things to adjust and it's yeah, it's really cool.
00:50:50
Speaker
Plants are awesome. And that concludes our episode logical point. But yeah, if you, we've got some resources, is that right? That we can recommend and put in the show notes for, you know, people looking for, uh, you know, what, what Agribon should they buy? Agribon that's a brand name, the spun row cover they should buy or, you know, what sort of, I know we've got, we had some plans for building your own,
00:51:19
Speaker
kind of what we call caterpillar tunnels, which you could walk in, but are smaller scale, and how to just build one of those. We have plans and things like that, which is really helpful. It tells you exactly what to buy, exactly what to do, and can be a really helpful way to boost your season by a month or so if you're looking to do something like that. On a small scale, you could put ... I know some growers who
00:51:43
Speaker
put them over their tulips to get tulips earlier. So they've got an area they plant things in and then they just have this structure that's temporary and they put over them. So there's lots of options for season extension on all different scales about that. But any lasting thoughts about frost?
00:52:01
Speaker
One of the tricky things about Caterpillar tunnels is that after a year, they turn into butterfly tunnels and they fly away. You take their wings and you can reuse those. Yeah, like stained glass. Pretty cool stuff. I associate them with being French, but I'm sure they're just global.
Extending the Season with Cold Frames
00:52:24
Speaker
The little boxes with the glass on them, people use them for starting seeds. Cold frames.
00:52:30
Speaker
Yeah, cold frames. Cold frames are a way to, you know, if you if you have, you know, early stuff, you can, I've seen people build almost like a variation of a cold frame where we used to paint of glass. Yeah. There's a cool way to heat them with compost. Yeah. The compost produce enough heat. And that's how mom would grow her tomato transplants, the early ones. And you would see
00:52:55
Speaker
it'd be really cold out and you would see all the little drops of water on the inside where it's nice and toasty. We need to do an episode on alternative heat sources. I think that would be really cool. We had that solar tunnel slash greenhouse or whatever at the farm at one point and just talking about how that came together or compost. I don't know, that would be a cool episode. If you also think that would be a cool episode, please send us a message or leave us a review that says, hey, I want to know about that because that sounds fun.
00:53:25
Speaker
I think my final word of encouragement would be if you're sitting at your house or wherever and it's getting toward the sun's going down and you think to yourself, I'm
Final Frost Protection Advice
00:53:36
Speaker
tired. Those plants will just be fine. I'm not going to cover them. It'll be fine. Don't just get up. Don't go do it real quick. It won't take as long as you think. And you'll be glad that you did. Um, speaking from experience.
00:53:49
Speaker
Oh yeah. And my other, on that note, do it earlier before it gets super cold and start trapping some of that heat. So that was one thing I started doing this year was I closed my tunnel earlier so that it's holding onto that heat, even though it doesn't necessarily need to be closed yet. So I have been doing that. And I think that's made a big difference for me as well. I just had visions of you like running with the plastic behind you, like a parachute.
00:54:14
Speaker
capturing the heat and then landed down onto the plants. It's like my cake flying behind. The grape peony raised. I'm good with that. That's fine. It can be only one. All right. Awesome. Well, on that we are thankful that you were here with us today and
00:54:36
Speaker
Like we always say, please feel free to reach out to us on Instagram at Hort Culture podcast. Feel free to shoot us an email that's in the show notes. We've been getting some of those. So thank you for those of you who have sent them. We do indeed read them and discuss them and plan accordingly. So thank you and answer any questions that you guys might have. And yeah, so we hope that as we grow this podcast, you will grow with us and that you will join us next time. Have a great one.