Friday, April 30, 2010

Rerun: Late Frost and Tender Seedlings

I ran this post last year, just after a late frost in the middle of May. It occurs to me that running it a bit earlier this year might prevent some over-eager gardeners out there from planting too early and risking damage to their tomatoes and other heat-loving plants.


Here I am gardening in hardiness zone 6B. Depending on whom you believe, our average last frost date is either May 5th or May 10th. It's May 19th and there's frost on the grass outside as I type this. I watched my neighbor cover up his tomato seedlings yesterday evening, as I brought my tender heat-loving seedlings indoors for the night. I'm not going to gloat. I hope his seedlings made it. He built some beautiful wooden trellises this year to support his plants. But I am going to take this opportunity to throw my own piece of two-bit advice into the marketplace of gardening ideas.

Don't plant your tomatoes as soon as your last frost date has passed. Don't even plant at a certain amount of time after that date. I'm not saying this simply because of the chance that a late frost could surprise you. The thing I watch for is the day when I can be reasonably certain that overnight temperatures will no longer fall below 50 F (10 C). I know this will come at least a week or two after our average last frost date, and possibly three weeks later or more. I watch the five-day weather forecast, and I won't plant until I see five solid days of overnight temps above 50 degrees. If the predicted overnight low a few days out is exactly 50, I wait. If I see an overnight temperature of 51 or 52, I might plant with a row cover. But mostly I wait.

Why do I use this temperature as a guideline? Because tomatoes are essentially tropical plants. Yes, they've been bred to survive in our northern climes. They'll live through 40 degree nights. But they won't thrive. In my experience, any tomato fruit which has ever been exposed to temperatures below 50 degrees will never develop a good tomato flavor. Even if that fruit is a tiny green bud that has just shed its blossom. And what are we growing our own tomatoes for if not for superb, better-than-candy flavor? Tomatoes need heat and are completely allergic to cold, especially at the beginning of the season. Other gardeners get earlier tomatoes than I do. But the fruits aren't worth a damn, in my opinion.

Even my earliest fruits don't compare to those that mature during the three golden weeks of August. Those fruits probably never know temperatures below 60 or even 65 F. Now those are tomatoes worth eating. They're also worth waiting for. That flavor is the reason why I gave up buying fresh tomatoes at the grocery store, no matter what it says on the sign. "Vine-ripened," "hothouse," - whatever; I don't care. Once you've tasted a real tomato, you won't see the point of eating those red globs of cardboard that are offered for sale 52 weeks out of the year.

All of this goes doubly for pepper plants. They are even more heat-loving than tomatoes. As a rule of thumb, I aim to have my tomatoes in the ground on June 1st, and my peppers in the ground in mid- to late June. That's what works for me in my area anyway. Just don't let your tomato or pepper seedlings get rootbound as you are waiting for the temperature to cooperate. Repot them in larger containers if you need to. Rootbound plants seldom recover to do well in the ground.

I'm sure that seasoned gardeners have their own habits and preferences based on long experience, and I don't intend to start any argument. Direct experience is the best teacher, and it should not be lightly set aside on any authority. My recommendation is offered however to novice gardeners, and I understand that there are many people taking up gardening for the first time this year, due to our lousy economy. It's very easy to get discouraged when our first attempts at any new enterprise fail. So if you're new to gardening, don't necessarily follow what your neighbors are doing. Gardeners can be notoriously optimistic about frosts and planting dates. Everyone is dieing to get that first homegrown tomato. You may do better to wait it out with your heat-loving plants.

Gardening can be an extremely frugal hobby. But it's only frugal if you manage to keep your plants reasonably happy and productive. Losing plants you've grown from seed is absolutely heartbreaking. So take rules of thumb about planting dates with a grain of salt, and beware those late frosts!

12 comments:

Dana said...

Thank you for this post. I was planning to put my tomatoes out today, because we've had such a warm spring, but you've changed my mind! I realize I'm just over-eager to get things planted. I will take your advice about the 50 degree low and see how good my tomatoes are this year!

SwineInsanity said...

Hello! Not sure if you know about these. http://www.gardeneer.com/tomatos/a3_seasonstarter.html. I put them on my plants to set them out sooner. I put a put over the plant after I planted it. Then I filled the tubes up with water and removed the pot. It acts like mini greenhouses and can be used every year. Thought I would tell you about it in case you didn't know. Cheryl

SwineInsanity said...

SOrry, I should have proof read. Ugh... Or got another cup of coffee.. (I have posted in the past on your comfrey posts...) Where I said"I put a put over the plant after I planted it. " I put a Pot over the plants. Sorry. I also posted about it on my blog after I posted the previous comment.

Kim said...

Over-eager, here too. I have been trying to talk myself into putting those tomato and pepper plants out early. Thanks for the timely post.

Gardeness said...

We live in the same area as you do, and last year we planted all of our seedlings on May 16th, only to have every one of our tomatoes, peppers, eggplants and basil killed by that late frost. My plan for this year is to hold back a few seedlings, instead of planting everything we have, in case of a similar catastrophe. We're planning on planting the bulk of our summer veggies in about 2 weeks, but I'll keep in mind your suggestion, and check the 10 day forecasts for temperatures below 50. Thanks for sharing this advice!

Teresa/Safira said...

Thanks for the timely reminder. We haven't had frost in several weeks here in southern MA, but it's still getting darn cold some nights. I might put a couple of Oregon Springs out in big pots and haul them in when it gets colder, but I'm holding off on the bulk of the tomatoes and certainly the peppers and basil!

dltrammel said...

Thanks for the advice. My tomatoes are about to out grow their seed starters and I was planning on repotting them into peat pots to mature a bit more before planting them. So too with the peppers.

I did plant the first batch of my sunflowers, corn and cucumbers this past week, with beans, okra, melons and pumpkins planned for two weeks from now.

Any worry with those?

karl said...

we have been watching the temperatures very closely. we are 6b also. better sense has won out until present. this year things sure have warmed up early though.

Paula Adams Perez said...

So...hard...to...wait...

But your advise makes so much sense! Hey, did I miss it? I've been waiting to see your potatoes-in-buckets post. I live in zone 8 and wonder if it's time to do it yet? Thanks.

Kate said...

Dana, you're welcome and I wish you an ace harvest of tomatoes this year.

Swineinsanity, no worries. I often post before the caffeine kicks in myself. I've seen those or the like, but have never used them. How much do they cost, and how long have you been using them. I've wondered about the product lifespan for such things. I grow at least a dozen tomato plants per year, and I wouldn't want to invest in something like that unless they return were really there. Besides, at this point I'm used to waiting until August for that brief two-week tomato season anyway.

Kim, you're welcome. Glad this piece was timely for you this year.

Gardeness, I usually watch the 5-day forecast, since I think anything beyond that timeframe is mere guessing, at least for the area where I live. Southern Chester is a bit warmer than our area so you'll probably see the right signs in the 5-day forecast before the end of the month. I certainly won't even consider a plant out date for tomatoes, eggplants and peppers before our average late frost date. For that purpose I use May 10th as the working date. But as I said, June 1st is my personal rule of thumb date. Certainly has been a warm spring though.

BTW, if you're not familiar with PASA, I'd recommend you check it out. I think it would be right up your alley.

T/S, right there with you. It's been an unusually warm spring. This weekend was like something out of July!

dltrammel, I think sunflowers can hold their own against a frost. Corn is usually planted out after last frost date, beans a little after last frost date, and okra is a heat-lover on par with peppers. You might wait on that last one and plant them out when things are really warm. Melons I've little experience with, but squash likes warmed soil, so I go with little mounds and plant sometime around the last frost date.

Karl, not sure where you are, but only the knowledge of historical weather trends is keeping me from planting everything at the moment. It's like we're in the middle of summer here right now.

PAP, hope you've seen my latest post by now. It covers the potato buckets.

SwineInsanity said...

When I bought my plant protectors last year it was about $13 here for a 3 pack. This is my first year using them, so I don't know how long they last.

Andy and Cheryl said...

I used those Plant protectors. I live in Puget Sound, Washington. The potted plants seemed to do better in the pots than the ones in the plant protectors in the ground. I have seen one gal have good results so I may just have to continue to experiment. But I wanted to keep you posted.