Our average last frost date is April 2 and I normally try to plant the early tomatoes the second week of March. I use modified dry ice shippers to protect the plants from frost. The soil temp is normally 65 degrees when they are set out. The shippers also protect the plants from wind.
I put the lids on if the forecast call for temps below 40 degrees.

Those containers appear to have a foil liner which should also help reflect light onto the plant. Interesting...

psa said:Last frost date works well around here. While tomatoes won't grow too much in cooler temperatures, you want them to get a chance to settle in and put out some roots before the heat pushes them to grow. Additionally, if your tomatoes don't come from a source that grows them cool, they will need the cooler weather to help them harden and trigger early bloom and fruit set.

Paul,

I would like to know more about growing them cool. What temperature is considered "cool"? At what stage of plant growth is this critical. I have a tomato book that mentions 13ºC (55ºF) when the plant develops the 4th set of leaves. Does that match you advice?

Yes, 55ºF is usually ideal, striking a balance between stimulating good growth and hormone regulation, and encouraging pathogens at lower temperatures. Of course, you get faster, more luxuriant growth at higher temperatures, so not all sources follow best practices in producing plants for consumers (as opposed to the greenhouse and commercial production industries who are very picky about such things). Individuals growing their own plants from seed often have difficulty maintaining this temperature unless they have an outdoor controlled temperature greenhouse. This brings us back to the fact that home growers can recover some of the benefits of cool growing by carefully choosing when to plant.

And remember, just because you don't see much growth above ground doesn't mean they aren't growing. Often the are making amazing roots below the soil line. A clear container allows you to see the root development.

My wintersown tomatoes, these photos taken in April 2011. Outside in Ohio in April, they tend to be at cool temperatures. I can't say at that temp they grow, because they are at the mercy of Mother Nature. You can see how small the plants look, growing in their 16 oz. cups


But you can see the roots through the cups, already reaching the bottom of the 16 oz. cup. By the time they're planted out in May, they're still tiny above ground (as in my above post), but they have huge roots relative to their small size


Karen

Karen,
Do you find that your plants are heavy producers for flowers & tomatoes since they are grown cool from get go?

Usually, but honestly, there are good years and bad. I only grow 6-8 plants a year. Last year they weren't very productive, but most people in this area seemed to have similar results. We had the worst heat and drought in decades and most plants (veggies, flowers, everything) didn't do well.

Most years, those 6 to 8 plants produce more tomatoes than we can eat and give away.

Karen

Karen, When would you recommend that I wintersow tomatoes? Typically, I would transplant plants end of May. late March to ws?

I don't know about your cold climate, Joanne. I sow my seeds around March, and keep the containers in morning sun. I would guess you could sow them around late March, and they'll germinate when they reach adequate temps.

That said, if I were you I'd just experiment with a few, and continue to grow most under lights as you usually do. Just in case I just don't know how well the WSown ones would do in such a cold climate.

Also, if we get a frost/freeze after my seeds are up, I do give them extra protection overnight by throwing a blanket over them. I do that for toms as well as tender annuals.

Karen

Ok, thanks Karen. Yes I will be starting lots under lights. One community garden pre-orders about 80 every year (mostly Heirloom). I'm going to try ws some early varieties and see what happens.

psa said: ... Additionally, if your tomatoes don't come from a source that grows them cool, they will need the cooler weather to help them harden and trigger early bloom and fruit set.

Being a novice, this is new to me and now I am wondering how they grow the tomatoes that are used for late summer planting. We have two growing seasons in east Texas and you will commonly see tomato plants for our fall garden being marketed in July/August.

And following this line of thought, those I start from seed for the fall garden will not be productive as our summers are sweltering?

We can't safely put anything in the ground until the first week of June...and even then we sometimes have to cover them at night for a couple of weeks.
We start them in the house late March and when the day temps warm up they can spend some time in the greenhouse...most of May...but if the night temps drop too low in May they come back in the house at nights.

I'm with you Kristi, a Newbie and close to your Zone. Plus in my shady yard I fight for the sunshine. I managed a less than so-so crop of tomatoes last year It's too bad they were grape tomatoes, So I am going for Patio tomatoes this year since space is also an issue for me. After I do some modifications this weekend to my raised bed garden on the deck, if I can find tomato plants at my favorite nursery, they are going in when the paycheck arrives. I suck at planting seeds so I won't ever go there.

I'm similar to Joanne (same city) in that I start my tomatoes indoors, but don't have a greenhouse. I grow almost all my tomatoes in large pots, and very seldom put them into the ground and therefore usually choose fast maturing determinants. The season is so short that only having one flush of blooms isn't an issue. I usually start the seeds in late February.

I tend to move my tomatoes outside and out from under the lights very early--usually when the daytime temperature is around 10C. Even though that is a bit cool for growth, I've found that earlier transition to sunlight helps the plant adjust more easily to natural light and to transplant when the temperatures are warmer. July is about the only month here where the night time temperatures are over 15C, so the objective is to have them fully mature by that time to achieve optimal flowering.

Kristi, one of my best tomato crops I had was when I babied my spring tomatoes through the hot summer into fall. I had tomatoes coming out my ears! That was the first year I gardened and I didn't know that tomatoes didn't live through the summer here. I have heard that you can take one of the branches on your established tomato plants and lean it over until it touches the ground. Anchor it with something to keep the branch on the ground. It'll root and start a new plant. Then you can clip your old plant and you have a new plant for the fall.

Lucky you, having a spring and a fall season. No such thing as a fall garden here, the hard freeze zaps everything by mid to late October, then nothing grows until about April. Some years I can plant spinach or other frost tolerant seeds in April, but usually not until sometime in may. Tomatoes never go out until after June 1, and then with nighttime protection. We can still have killing frost as late as early June.

I wish I could grow maters...I love them, but they hate me. No matter what I do I just can't seem to grow them. for friends who can and are happy to share. I also like zuccini and get blessed with lots

my last frost dsate is usauyally may 15th but after getting burned two years in a row with frost i now wait until the first day of june to put my plants out

Frank, my data confirms that; it says that you have a chance of frost up until June 2nd.