The Problem with Last Frost Dates (Cold Climate Gardening Challenges)

Añadido: 2026-05-14

[00:00:00]It's miday. I should be planting my tomatoes out, but instead watching the forecast for another freeze. Honestly, I think that this is probably the greatest challenge for cold climate growers, and it's harder now than it used to be to navigate this challenge.

[00:00:18]It used to be that we knew we had a short season. Everything was easier to follow by the book. We had our last frost date, our average last frost, between May 20th and May 24th. So we always knew after our mong weekend we could plant out our delicate heat loving crops and we knew we had a certain window of time before that first frost came in the fall. It was predictable.

[00:00:39]But now our average last frost date is not that meaningful anymore. Our average last frost date has shifted all the way up to May 10th to 12th that range in there. So it's always been around Mother's Day weekend as long as I've been gardening in the city that I'm in now. But that has become less and less meaningful because we get these erratic swings in temperature. We get frosts well past that. But it's not predictable. So you can look at your twoe forecast and think, okay, it's looking okay. And then the day before all of a sudden there's a freeze. And this happened last year also. It was a cold cold May and June. Actually, we had a couple heat waves in May and then we had freezes at the very end of May. I didn't get beans, cucumbers, or squash germinating until the middle of June last year, which is not fair. I need more time to grow food. Most of what's in this outdoor greenhouse here, this little deck greenhouse, are my tomatoes.

[00:01:36]And they're out here because I can't plant them in the ground, but they're also very unhappy inside under the grow lights. They've outgrown their pots.

[00:01:44]They need to get planted. I time my seed starting based on two things. one working backwards from when I want to harvest and I want to be getting tomatoes at the beginning of July, which means I need to be starting the seeds inside mid-March at the latest. I start some even earlier than that. And then the other thing that I I base my tomato starting dates on is the expected last frost date. The average last frost date is based on the 30-year average. So the last 30 years, what was the average last frost date? So that date is constantly shifting over the years because the average is calculated based on more and more recent years. But it just makes it really hard to predict when you should start your seeds to end up with the healthiest seedlings to go out into the garden because that end date of when they actually move out is just not something you can predict within a 2 week period anymore. Well, you can predict it within 2 weeks, but not any more specific than that. It's actually starting to get steamy in here. I think it's heating up really quickly. So, I'm going to open this before I walk away.

[00:02:44]So, I mentioned last year we had the same kind of spring where it was cold until June, and I didn't get my cucumbers or beans or squash germinating and growing until the middle of June.

[00:02:55]And I didn't want to do that again this year. I didn't want to wait. So, I did start cucumbers and squash in pots. Um, you can absolutely do this. I just hadn't really had a need to do it over the last 10 years. Usually, I'm able to get them in the ground by the middle of May, the seeds, and it's hot enough that they germinate and grow right away. But I did decide to go ahead and scrge up some more pots, some more soil, and last minute throw in some cucumbers.

[00:03:21]And uh who else have we got here? Little pumpkin. There's a bunch of these little guys here that in probably a week and a half, I'm going to feel comfortable planting out in the garden. I don't like to plant them very early because they can get quite unruly and quite unhappy indoors in my experience. Going to walk through a little construction zone here.

[00:03:43]Kim has been working on our outdoor kitchen. So, right now she's got the clear roof panels on top and uh there's a little bit of like finishing up to do on the actual roof structure part and then she's going to be able to get to work on building the kitchen and it's going to be awesome and I'm really excited. And of course, she built this pergola last fall and into the winter.

[00:04:05]She was working on it in the snow. So, one of my greatest frustrations when the weather is like this in the spring is that things just don't grow. The soil stays quite cold. It's It's really not warm enough to get things growing fast or vigorously. And here is an example.

[00:04:23]These radishes were sewn. Oh gosh, I have to look back at my records, but I'm pretty sure I'm pretty sure I sewed these the first week of April, maybe like April 8th or something like that.

[00:04:35]Um, so it's been over 30 days. Radishes in the prime conditions only take 30 to 35 days to be ready to harvest. And they have just not budged. They sprouted and they grew their leaves and that's it.

[00:04:50]And they're not budging. And it's because it's been so cold. Um, cold and rainy. Not a lot of sun. That's another factor. But mostly it's just the cold soil, cold air, constant freezes every night. This is actually the first time I'm seeing the pack choy here look like pack choy. So, it's just starting to look like what it should look like. It's just looked like a tiny little seedling with codalons for the longest time. So, that bed there is a mix of um pack choy and radishes. and I sewed arugula, but I'm really not seeing any arugula coming up. So, maybe we'll reso. Um, those are crops that are fine with the cold weather. So, it's something that I always sew early. It's not that I love eating a ton of radishes and arugula. I mean, I do love radishes. We pickle them, so we can go through a lot of radishes. But the reason that I sew so many filled an entire bed is that I want stuff growing early. And there's only so much that you can actually get growing that will feed your family at this time of year in this climate. So I will always go for really cold tolerant crops really early on in the hopes that I'm going to get fed earlier from the garden. But when it's just steadily cold like this, things don't grow and that is annoying. You just sit here and watch and wait and nothing changes. If you're a gardener and you've sewn seeds before, I'm sure you can relate to that feeling of just staring at it and watching it grow and waiting for it to grow. Like watching a pot of water that you're waiting to boil. So radishes, arugula, cho, Asian greens, things like that. Uh in this bed we have here, this is scallions. So things like green onions, um and any onions really. They're pretty cold hearty. These lasted all winter long in this raised bed with a cover on.

[00:06:36]And then we've got some lettuce that we started inside. Colabbies started inside. And then some direct seeded kabies. Lettucees.

[00:06:46]More lettucees. This is a perennial sorrel.

[00:06:50]But like these seeds have been in this garden for over a month, probably 40 days at this point, and that's all we have to show for it. And these are supposed to be very fast growing things.

[00:07:02]So, it's just been frustrating. Carrots are another thing that you can sew and grow earlier, but again, if that soil is really cold, it's going to take them a really long time to germinate. So, one of the things that I do to help speed things along is to use plastic row covers. If you do not have a nice greenhouse where you can keep things growing, under here I have beets which are very cold tolerant and without this plastic on they did germinate and they did start to grow but it just takes them so long and if you add a little bit of heat with a cover like this you can see overnight, well over a day that they just start shooting up in growth. So a little bit of heat added is beneficial.

[00:07:44]Just don't fry them. So it's morning now that's the east. The sun's in the east still. As it moves overhead, I'm going to open up these row covers because I don't want to fry what's in them.

[00:07:54]They're just heating up a little early with the beautiful morning sun. Now, our expected high temperature today is 10° C. Not that warm yet, but definitely warm enough for beets. I'll show you the little babies.

[00:08:13]Now, I also have this insect netting on here, and that is to keep the squirrels and chipmunks from digging out the seeds, but they're doing pretty good in there.

[00:08:23]Couple different varieties.

[00:08:27]This is just our first sewing of beets.

[00:08:29]And last year, I grew a ton of beets in one pot on my deck. I'm going to do that again this year. It worked really, really well. Over here, I've planted some Swiss chard. Excuse the mess on this bed. I'm going to be dealing with these sticks soon. Um, but I put these containers over top of them. I saved these containers, cut the bottoms off, and then they make really great um, temporary greenhouse covers. So, even though it went down to 1° C last night, potentially even freezing, it's totally fine. Celery. Celery over there and Swiss chard are other examples of cold tolerant things. Um, spinach. Spinach is a great one that doesn't mind the cold.

[00:09:10]This spinach looks a little gnarly because it is for um saving for seed.

[00:09:15]So, it's last year's spinach. We're just letting it go to seed. Looks like it's already starting. Holy.

[00:09:22]I've never had spinach start to go to seed this early before. That's wild.

[00:09:26]Usually, it's day length sensitive, and so it will bolt once the days get to a certain length, which is usually the beginning of June. Um then all the spinach has shot up and gone to seed by then. And you really can't prevent that.

[00:09:38]but also it can be sensitive to extremes. So from very cold to very hot.

[00:09:43]If you have a lot of those fluctuations, then it can also trigger it to bolt earlier than that. Um I wouldn't say we've had any hot weather. So either way, it's started to bolt. But then I also have spinach, which let me pause.

[00:09:56]Okay, I just came back over to my deck area because I've got this sprout box bed uh next to my deck. And this spinach I also sewed I think I sewed this mid-March and I had a plastic row cover over this bed but it is not growing.

[00:10:09]Come on. This is ridiculous.

[00:10:13]Spinach is supposed to grow way faster than this. By the time it finally gets big enough to harvest, it's going to be time for it to go to seed. And spinach is something that we usually grow a ton of. We grow enough for the whole year so I grow enough to freeze and then we can use it in our cooking through the year.

[00:10:30]We've only had two good harvests of spinach so far this spring, and it was from the overwintered spinach from last year. So, another example of how things are really slow to grow. And I've showed you my peas.

[00:10:42]I uh I don't really direct sew peas very often. I usually start them inside and then I plant them out just because the plants, the seedlings themselves can tolerate lower temperatures and colder soil than the seeds require to germinate. And so it really does speed things up to plant out pre-germinated seeds in your garden. And uh my peas really really struggled from mismanagement this year. I fried them under a row cover and then I froze them outside at night. Well, I didn't, but the weather froze them severely. It went down to - 9 C. They're okay.

[00:11:17]So this is the pea bed. I have it wrapped in chicken wire because of the rabbits. Um and all these sticks are to trellis it. This is a dwarf variety of peas, so they don't need a big tall trellis. Sticks will do or even a single string. These actually have their first little blossoms of the year.

[00:11:37]So, not bad. But my point here is that they're so small. These peas are so small still. Yes, they're a dwarf variety, but they still grow to 24 in or so. And they shouldn't be this small and flowering. Like, they are stunted. and anything I've direct sewn. I've direct sewn some peas in here, too. Um they are at this point maybe 3 in tall. It's kind of hard to see what's what in there, but um they are going to catch up now. It's just it's hard it's hard to predict.

[00:12:04]Now, with frost and light freezes, peas are going to be okay. You really don't have to worry about them. They'll be happier if you can cover them, give them a bit of warmth. And so, like with my carrots here, I could have had these growing faster if I'd put just a frost blanket or something on top. I just didn't get around to it. You only have so much energy in the day and sometimes I just have to let nature do its thing.

[00:12:28]Go along for the ride. I can't always be out here controlling everything. I already do the row covers. Can't do it for all the beds and all the gardens and all the crops. So, the carrots are growing. They're just fairly slow still.

[00:12:40]Those little babies. Oh, I saw the coolest bug in the soil yesterday.

[00:13:04]Under this row cover here, I have sewn my bean seeds. So, beans are another one of those things that need it quite warm in order to germinate and grow happily.

[00:13:13]not warm enough yet to grow beans just out in the elements. But by keeping a plastic row cover on here, it heats up quite a bit during the day, which then heats up the soil. And at this point, even if we go down to minus1 Celsius at night, just below freezing, it's still going to retain its warmth. The black soil absorbs the heat and uh the row cover helps keep some of that heat in.

[00:13:37]Uh so I do have bean seeds sewn. I just sewed them two days ago, maybe 3 days ago. Let me see if we can see anything here. No sign of any beans coming up yet, but ooh, it's nice and warm in here.

[00:13:53]Very nice and warm.

[00:13:56]Oh, and then over here, there's a couple more things that are fine with the cold weather that I don't even bother covering. Got leaks. This is rhubarb flour that the kids have been throwing around, but we've got leaks in here that are fine. And some spring turnips. I mean, it's in the name. Spring turnipss do well in the early spring. And what is this?

[00:14:20]H I don't know what that is.

[00:14:23]Anyway, there's also spring turnipss planted in here. There's some rudabggas, some more k robbies, and some parsnips, which haven't come up yet amongst our garlic.

[00:14:34]Those are all things that are going to be totally fine with a freeze. I mean, if it went down to like - 7 or 8 Celsius, I would cover them for sure, even just with a frost fabric, just to help them out a little bit, keep them a little bit happier. Now, one of the things that is most negatively impacted by these dramatic swings and and unpredictable late frosts are our perennial fruit trees, fruit bushes, things like that. Um, peaches, their buds can handle, I think, down to minus2 Celsius before they're completely frost damaged and will not produce fruit anymore. And even at that temperature, you can still lose blossoms because because they just they don't tolerate being frozen. And so our peach tree has just been lovely so far this year this spring.

[00:15:25]And luckily for us, it didn't start blossoming until the first couple days of May, I think. And so when we had a couple frosts and a couple freezes, it was okay still. But now the buds are open. And yesterday when I looked at the forecast, it said that tonight's temperature was supposed to be minus3 C, which would mean that all of these blossoms would be toast and we get no peaches. And same with our we have Asian pear and we've got plum blossoms over here, European pear here, and the apple trees got eaten by the rabbits, so it's not amongst my list of worries. But we've got all these beautiful plum blossoms, and we've got pear blossoms over here that are also stunning.

[00:16:10]And all of that would be lost if it went down to minus three. Uh, and it's because we can't cover this many trees in a large scale orchard. They do lots of things to try to save their blossoms.

[00:16:22]When this happens, they can rent helicopters or they have helicopters that they use to push warmer air down onto the trees. Um, there are misters that they use. So, if you spray buds and blossoms with a fine mist constantly throughout a freezing period, that somehow, the physics is beyond me, but it somehow protects the buds and the blossoms from freeze damage. Um, and there's also a chemical, I don't know if it's an organic chemical or not, but it's something that orchards have available to spray on blossoms that is like an antifreeze and will stop them from freezing. So, like there are tactics that orchards will take that are probably very costly. Um, oh, and there's also the fires. You may have seen a lot on social media this spring.

[00:17:05]I think it was cherry orchards. They were bringing fires throughout the entire orchards, like carrying and setting fires through the rows of cherry trees to try to warm it enough to protect the blossoms. Because one erratic freeze that is beyond the point where the blossoms have already opened can decimate all of your fruit for that year. So for us, it means we don't get fruit. we don't get peaches or cherries or whatever gets damaged uh in that year. You don't get another chance until the next year. And for those orchards, it means an entire year's income is gone. So, it's serious. It's really serious. Um and I was doing a bit of reading on this and it does seem like in the last couple of decades, the problem has gotten worse. So, the trees are waking up earlier because we have warmer winters overall and it feels like it's going to be an earlier spring, but then we get these freak late frosts and late freezes just because the weather is kind of like this, just less predictable.

[00:18:03]Those average last frost dates just don't mean as much anymore. So, for us, we could try to cover these, although it's quite an ordeal. When we thought it was going down to minus 3 tonight, we planned we had teaosts. We were going to stake them in and try to drape something over um a big tarp or something like that. And it still if it freezes then it's not like keeping frost off the blossoms is going to help. So I'm just really thankful, really thankful. It looks like it's only going down to minus one. So at least most of these blossoms should be okay and we should still get our peaches this year. Thank goodness. I mean, who knows? Maybe the end of May we could still get a frost that kills them, but we'll just have to play it by ear.

[00:18:44]Wait and see. Asparagus is another one.

[00:18:47]I have asparagus in my front yard and it thought it was time to wake up from dormcy and it started to send up its spears. And then we've had very cold nights since then. I mean, we had a minus 6 night since the asparagus came up out of the ground and it can't handle any freezing. So, I've had to cover my asparagus, which you shouldn't have to worry about perennial crops like that.

[00:19:09]You know, it makes sense that if you're going to try growing sensitive crops that really don't belong in your climate, like tomatoes and peppers, like they're not things that grew here in Canada before we brought them here. Um, that makes sense. You might have to baby them. You know, they're they're here because of us, so we probably have to baby them along. They don't belong in this climate. But things that are perennial here, things that should be able to grow here, it's just it's a little bit discouraging that they are now requiring our assistance as growers and gardeners more and more so that we still get a harvest. Now, the fruit trees and the asparagus crowns, they're not going to die because of these freak late frosts. It's just that we won't get to enjoy the food from those plants because of the freak late frosts. So, if we did nothing, nature would be fine.

[00:19:58]the plants would survive, but we wouldn't get to enjoy our our fruit and our asparagus. Another thing that I do as sort of a a resiliency measure in growing food in a climate that can be very unpredictable is do a lot of succession backups. I can show you our brassasica successions.

[00:20:18]This tray here, it's actually our third tray of brassacas.

[00:20:23]And that's because most of the brassacas that we started earlier in uh late February, they died in the field. Um we had very cold nights and then the sun came out and scorched them under the row covers. So even under row covers, some of the nights that we had like - 9 Celsius was just too much for those brasacas and they died. Um so then we sewed replacements. I also had issues with my fungusnats inside. So, some of my succession sewing losses were because of that before they even got outside.

[00:20:54]Uh, but brassacas unfortunately are very sensitive to extremes. And so, if they do a lot of this, going really cold and then really hot, it can cause them to bolt or just send out their flower stock prematurely. And what you eat when you're eating broccoli and cauliflower is a very slow forming flower head that doesn't yet open. So, it gets really, really big. That's your broccoli or your cauliflower curd. You cut that off and you eat it. If you left it on, it would eventually open into flowers. But when they get stressed from too many ups and downs in temperature, it can trigger them just to send up a flower stock right away and not form that nice head that you're used to eating. You can still eat a flower stock from broccoli or cauliflower, but that is not what we are in it for. We are in it for nice huge white cauliflowers that we can slice and grill. I'm not in it for a bunch of flowerheads. So that's one thing that we do is just multiple sewings, make sure we keep them coming.

[00:21:49]Worst case scenario, we have more plants than we have space for if we've oversewn and we keep doing these successions. Um, and then we can give them away or sell the seedlings. But best case scenario, we get some in the ground that tolerate the extremes and survive and give us earlier harvests and then we plant a next round that maybe the weather will be perfect for. And if it's not, then we have another round planned. and surely the weather will be perfect by then.

[00:22:15]Also, with broccoli and cauliflowers, I like to do a variety of seed varieties.

[00:22:20]I like to sew some that are known for their heat tolerance, so they are not as inclined to bolt or send up flowers just because of spikes in heat and temperature. And then I also like to sew some that are known for their resilience in the cold. And if you have a good mix like that, then you're more likely to get something that'll do okay, even if the weather is really temperamental.

[00:22:41]Here's our little baby Brussels Brussels sprouts. These empty spots right here are red ball or red bowl Brussels sprouts. And my mom and I have tried to grow the red ones for years. I've bought seed from multiple sources. I always use new seed and they either just do not germinate or they just fail to grow. For years, we've tried the red ones. So, if you have grown red Brussels sprouts before, please tell me the seed variety and where you got it from cuz I'm really intrigued. I really want to try it out.

[00:23:11]It just hasn't worked out for me. So, springs like this can feel very discouraging and very frustrating when you're just waiting for things to grow and they aren't growing and you finally get things growing and then a frost comes and nips them back or kills them.

[00:23:26]It's discouraging. It's frustrating.

[00:23:28]But, um I try to remind myself of all the benefits of growing in a cold climate.

[00:23:34]Like really cold winters are also really good for reducing pest pressure. And we can grow some things all year long or all summer long that they can't grow in the south. They can't grow where it's warm. Um things like broccoli and cauliflower and spinach. They could maybe do that through the winter, but those plants just don't tolerate the heat very well. I mean, there are surely um heat tolerant varieties that work well. But just for your typical vegetable garden, those crops are way easier for us to grow here. And I love to take heart in the perennials that I know will do fine. Even though sometimes we have to worry about damage from frost. Here's another one of the fruit trees with full of blossoms. This is an Asian pear.

[00:24:18]But like look at the lovage. Look at the lovage. It's so lush. It does not care that we've been getting freezing nights.

[00:24:25]Doesn't care at all.

[00:24:28]And herbs, oregano, and sage.

[00:24:32]They don't care at all. Even like selfsewn self-seeded lettucees actually are just much more cold tolerant and and tough than seeds that you sew directly yourself in the spring or seeds that you start inside. I don't know what it is but selfseeded lettuce. So when you have a lettuce plant and you let it go to seed in your garden and it just drops its seed everywhere.

[00:24:56]That's what all of these plants are here.

[00:25:00]And what it might be actually is just the strongest survive. So, if there's literally hundreds of seeds, then maybe the weakest ones don't look great. They don't look any better than the ones you started inside. But you have better chances of getting a bunch of strong seedlings, too, when there's hundreds.

[00:25:14]So, maybe that's the difference. I don't know. But self-seeded volunteer lettuce is also one of the strongest early crops. And things like garlic. Garlic can always handle freezes. It does what it wants. It knows when to start growing after the winter. Things like rhubarb.

[00:25:30]Rhubarb is really tough. doesn't care if it freezes. It pushes up through the snow. Look at this rhubarb plant. It's massive. My kids were picking leaves and throwing them everywhere. But it's just it's such a happy rhubarb plant. This is the one that we forced this year and now the other one's caught up. Native berry plants are also very resilient, very tough. We have here a nanny berry that looks like we're going to get some berries on it this year. And obviously our service berry out front.

[00:26:01]Man, that thing's a stunner. And it should be loaded with fruit again this year. These plants are just much more resilient than the tender annuals that we bring in from other parts of the world and try to make work here. So, it definitely helps me to think about all of these resilient crops that just do well in these erratic temperatures and cold weather. Doesn't mean it's any less disheartening or stressful when things die from frost that you weren't expecting, but it does help. It does help to focus on the things that you know will do well where you live and things that you have to worry a little bit less about. Let me know in the comments if you are also growing in a cold climate and what your spring has been like so far. I'm curious if it's just us who has been experiencing the late freezes um or if you were able to plant out on your expected last frost date. If you live in an even colder part of the country or the world then uh I have nothing to complain about. you're probably used to planting out at the very end of May or the beginning of June, but it's really all relative, right? It's about what you're used to being able to do and then these freak freezes being thrown in after that expected date, no matter when that expected date is. That's what's frustrating. I want to leave this on a positive note, though, because the sun is out today and after tonight, there's no freezes in our long-term forecast in the twoe forecast. Doesn't mean they're not going to pop up out of nowhere, but it looks like we are approaching double digit nights, 10 degrees Celsius at least at night by uh the weekend, which will be so nice. So, at that point, fruit's going to start forming on all the trees. The tomatoes are going to be in the garden. The peppers are going to be in the garden. I'm going to be direct sewing warm weather crops like zucchini, and everything's going to feel okay again. And things are going to start growing again. I'm going to be harvesting these radishes in a week.

[00:27:52]Thanks for watching and I hope that you'll come and grow with us.