Yikes, I will be sowing seeds for tomatos this weekend in my zone 5 and you already have plants too big for your lights?

I don't have a green house, but I do think you have started quite early.

I would bet money that if you started from seed this weekend and then compared the performance of your present plants to the ones you start this weekend you would see no difference and maybe the ones you start this weekend would do even better since they didn't get all stressed out by the confines of their small pot and start flowering prematurely.

I know you will see sources say start tomatos 6-8 weeks before plant out, but I start them 5 weeks before. I used to do 6-7 weeks under HPS lighting and I ended up with 3' tall plants.

Dear Justaguy,
Actually I've had very good luck starting my plants early. I've had "real" tomatoes as early as June, and they are really producing by July. I know a lot of people whose tomatoes don't start producing until the end of July or early August, so I feel I am ahead of the game. I've also started a few "Sub-Zero" plants which are supposed to be capable of setting fruit at lower temperatures. And I plant 'staggered' maturation types, so I don't end up with a bumper crop all at one same time. l also "stress" my plants by using a fan to simulate the natural wind so the stems grow thick and strong, which works very well (e.g. no lanky plants!). All of this early preparation really helps since I also do a lot of canning.

I did find on another post that some people put their plants out, but use a heating mat to make sure the soil stays warm. I did some checking and sure enough, if the soil is warm enough, even if the air is cooler, the plants will thrive. So I've decided to set my mat up on a timer and have it run from 8:00 PM to 8:00 AM just to make sure they stay warm enough, and we'll see what happens. I'm quite confident they will be warm enough out there during the day. If they get too lanky, I can always either pot them up some more (which I've done in the past, or "trench plant" them when I put them in, which I've also done. Both work nicely. But thanks for your input. I'm sure your plants will grow fine as well, especially with the added warmth of zone 5! MacThayer

Actually I've had very good luck starting my plants early.

I have put out 3' tall plants in full flower given that I grow under HID lighting and never have I had a plant produce much more than a 6" plant set out at the same time. I know a lot of people whose tomatoes don't start producing until the end of July or early August, so I feel I am ahead of the game.

You are waaaay ahead of the game. I have never known anyone to get any tomato plant to start yielding well in the beginning of July in Wisconsin other than very early varieties and even then it's iffy. I did find on another post that some people put their plants out, but use a heating mat to make sure the soil stays warm.

A heating mat isn't going to do much good outside. Ever felt that heat mat? It isn't hot, it's barely more than room temp. It heats gently. Given the cooler air temps around and over the plants I just don't see the heat mat doing much outside (maybe in a greenhouse). If they get too lanky, I can always either pot them up some more (which I've done in the past, or "trench plant" them when I put them in, which I've also done. Both work nicely.

These methods really don't work that well. They aren't optimal methods, but rather methods to deal with the less than optimal. A tall lanky plant get's it's stem buried because otherwise it would just get blown about in the wind and possibly sheared off.

A healthy plant doesn't require this, it grows in proportion, height and stem.

You are certainly welcome to start as early as you like, but you still have time to start more from seed right now (or this weekend, or next). Don't worry about me (who am I?) or proving anything to me, just try it and observe the results yourself.

There have been studies done on this and on these forums Dr. Carolyn Male has indicated that for the thousands and thousands of plants she has grown out, those started early are surpassed by those started on time. This has been true of my own experience as much as I wish it wasn't the case.

I also just started my tomato seeds recently (last weekend). I was thinking that I actually started them a bit early. ;) But I do have this little pond named Lake Michigan right down the street which keeps me cool in the spring. Last year I got my first tom (Stupice) around the middle of July with the later varieties ripening in the next week or two after that.

I know some people who start their tomato seeds in March and then either finish them off in a greenhouse/coldframe, or put them in the ground and take their chances. Nothing wrong with that, especially if you're aware of the weather and can employ wall-o-waters or other means of keeping your plants warm if the temps get into the mid 30s or below, like hauling them inside. It is a risk, but that's fine as long as you're aware of it.

I'd recommend a black plastic mulch or something else to warm up the ground if you're going to plant soon. The soil temp should be at least 50 degrees if you want your plants to grow. Also if you have a warmer spot, maybe sheltered from the wind on a south-facing slope, you can have a micro-climate which allows you to plant a lot sooner. My micro-climate is right next to my house where the furnace vents out. When it's cold outside the furnace is running and venting more, which keeps that area much warmer than the outside temps, and the house protects that spot from any northerly wind.

Good luck! Please let us know how this works out. I'm thinking with either a run over to the greenhouse to get more seedlings, or with gloating pictures of your magnificent June tomatoes. ;)

Mike

Oh, Boy, it looks as if I have a challenge on my hands! I LIKE challenges! I still have some leftover seeds, so I will also plant some more plants this weekend. Then we shall see if the ones I planted earlier outperform the ones I planted later.

Right now, my plants do not look "lanky". They look like they are growing beautifully -- just getting too close to the light. I have a good greenhouse, which is where they are going to go. I'm going to put the heating mat in direct contact with the bottom of the pot (in this case, they are those new pots made out of dried, pressed compost --- so kind of like a peat pot-- and 4 inches square and tall). The temperatures in the Greenhouse have been running 55-70, during the day, even on a cloudy day, and even higher on a sunny day. I also have a back up space heater if the temperatures fall too far -- or, as you said -- I could always just bring them inside overnight. So that's my plan for that. We shall see how my new seedlings do once they are planted.

I do understand what you are saying about those started "on time" surpassing
those started earlier. I have read that it has a lot to do with the length of day and the amount of sun the plant receives (REAL sun -- not just grow lights) which is one reason I want to get them into the greenhouse. So stay tuned, Justaguy and Mike, as this could be an interesting experiment, if you're interested!
MacThayer

I am interested. I think all us Wisconsin gardeners would like to find a reliable means of getting late season tomatos before frost kills the plants.

I do not have a greenhouse, so instead use my exposed basement with a south facing patio door and HID lighting. It has been my experience that regardless of when plants are started, they all even out in the end.

Perhaps growing in a greenhouse will prove advantageous here.

I moved mine out to my unheated greenhouse this past week. They're all looking very happy. I have one that was a "volunteer" indoors and it's already about 2' high! I had to pinch it back to keep it under control. The others I started about 3 weeks ago and they're about 6". We've had some nice temps overnight and I have my canna and other heat lovers in the greenhouse too. Everyone's thriving, especially with the warm day temperatures.

I started seeds earlier as well. Do every year, but I sell them to friends where I work in early May, so I want them to be going and hardened off at that time. Looking at what the night time temps are going to do this week, I will put about 4 of my flats out in my coldframe tomorrow, as they are getting stocky from the fan and are growing like weeds. If we are to have a cold snap, I would either bring them back indoors for the evening, throw a very heavy blanket over the frame or put an incandescent light bulb or 2 in there to keep things just a tad toastier than outside. Let us know how things go!!!