Tomato seedlings

[mnfathead]

Hi all, started a bunch of tomato plants again this year and they are coming along pretty well, one ? though, they seem to be going every which way, some straight up, some kinda laying down. Any thoughts as too why? lights too close? or is it just not a big deal?? any info would be great, thanks

[Nainoa]

Hi all, started a bunch of tomato plants again this year and they are coming along pretty well, one ? though, they seem to be going every which way, some straight up, some kinda laying down. Any thoughts as too why? lights too close? or is it just not a big deal?? any info would be great, thanks

If you mean that they have long weak stems that are too weak to hold the tops up... It means they are "Leggy"

When they fall down they are "Legging Over"

Leggy is a product of either the lights being too far or the soil temps being too hot... Or Both.

With tomatoes, you can usually fix this by adding soil to the stem and repotting them... As Tomatoes will sprout new roots from the stem. However if they don't have any true leaves yet and are just living on their original Cotyledon leaves, the chances of them living through this repotting is low, as they will be prone to "Damping off" before the new roots can grow and the stem will rot etc...

But if they are already Leggy, you really don't have any other option than repotting, giving them closer light and cooler soil temps.

[eurolarva]

I doubt the soil is too hot. Usually it is too cold especially if the plants are being started in the basement. This year I built a heat pad for my seedlings using plywood and rope lights then running them on a timer to control the heat and keep it around 75 to 80 degrees. My laundry room gets as low as 60 degrees and I had similar results with tomatoes in spite of the fact that I had 6 T12 bulbs and a 400 watt lamp. This year because of the heat pad my peppers look fuller, onions are bigger and the tomatoes are already flowering. Another problem that I face is I have to water every morning and every evening till the seedlings are big enough to plant in a bigger pot and the roots a long enough to be watered less often. When you start seedlings you need to should use a seedling potting mix with no fertilizer and do not use fertilizer till the first set of real leaves show up. Then the fertilizer should be mixed very weak. I use miracle grow and mix 1 teaspoon per gallon. Seems like a lot of work but this last stretch of winter is boring and it is nice to have a hobby

[Nainoa]

Well, flowering (If it's healthy flowering) is more about day length change, than soil temp. All the Solanum plants (Tomatoes, Potatoes, Peppers, Eggplant etc...) Are "Short Day" plants. They flower as a result of the day length getting shorter after the summer solstice. It's their reaction to the fact that they need to produce fruit before the coming winter. (This is why as the day gets shorter they try to produce more and more)

When a plant from the Solanum family flowers in the greenhouse, it is the plant equivalent of a 12 year old girl trying to get pregnant after her first period. It's a sign that the soil is either too warm in the juvenile stage or too cold.

For all the promise one might feel at seeing a flower on a tomato or pepper plant is actually a bad thing.

A Tomato is essentially a "Sugar Machine" It uses the chloraphyll in it's foliage to make the compounds that store as starch in the fruit that turns into sugar when the fruit ripens.

Just like how you don't want your daughter to get pregnant at 12, you want her to go to college, start a stable career and meet a nice man first. The same thing is going on here.

You want your Juvenile Tomato plant to be building strong roots, and then developing good foliage before it starts looking to be pollinated.

What will ultimately happen with those flowers, is you will put the plant in the garden... The soil in the garden will be colder than the soil temp in the pot it's used to and the plant will experience Transplant Shock.

Extreme Transplant shock will straight up kill the plant. What usually happens though is that modest transplant shock will cause the plants growth to stall out. And that stall out will cause it to drop the flower... Mild transplant shock it usually stalls out for a couple of days, then if you get some nice sun it gets growing and you don't notice a difference.

However, assuming you plant the tomato before June 21st, the plant's reaction to the natural day length will kick back in, the plant will realize that the days are still getting longer, which means it should be in the foliage development stage of life, and it will drop the flower.

However the chemistry of the plant in flowering and fruiting mode and foliage mode call for different nutrient profiles.

Fruiting stage needs more Soluable Potash... Foliage development needs more Nitrogen.

This change from one chemistry to the next, essentially putting the plant in Reverse, will/can in a cold spring actually set your plants back as much as 2 weeks.

Long story short... In ten years I have NEVER had a flower formed in the green house turn into a tomato that made it to the table.

I have however had plants that flowered in the green house end up being set back in the early stages after planting, and took until mid July to really catch up.

The ideal, for this cold spring is to get your tomatoes used to a soil temp of around 60 degrees... Which is a good guess for the temp you'll be planting at, and the closer to that temp they are used to the less likely they will be to experience transplant shock.

[eurolarva]

Granted I do not have the years of experience that you possess however starting from seed has very little to do with what the outside temp of the soil is going to be. Getting the seed to grow into plants and be healthy is the primary goal. Hardening comes when the plant has to go outside and live there. I can not debate you on the knowledge you have however the link here shows seedling optimum growing temps and most people like me grow more then just tomatoes. I do peppers and some herbs as well and because of it a compromise must be made.

[Nainoa]

See that link is just talking about Germination... The little plant emerging from the seed etc...

During Germination you want heat. I germinate in heated seedling trays with plugs.

Once the plant is at the stage where it's getting it's true leaves. Too much heat (Or poor light) from that stage on will cause them to grow too tall, too fast and they get "Leggy" if they get too Leggy, the stem can't support the foliage on top and they fall over.

Or say a plant gets a little leggy, but doesn't topple. Then when it goes out into the garden, the stem is on the weak side and ill prepared for the winds mother nature throws at it.

As close as you can come to ideal, is to keep the soil temp of your seedlings at 59 degrees... Then wait to plant them until the soil temp is in the garden is 60 degrees.

Going from the same soil temp to the same or slightly warmer is less likely to cause transplant shock.

If the soil temp of your seedlings is 75 degrees and you put them into 55 degree soil; Then planting will have the same (Transplant) shock on them as jumping into a cold bathtub would to you.

You want that transition from your Cold Frames where you've been hardening them to the soil of the garden to be as seamless and have as little change as possible.