What's the secret...

[barryla61]

...to getting thick stocky stems on plants that are started at home.

Is it best to have them in a dark room with fluorescent lighting only?

Is there a seed starting manual for dummies ?

I'm new to this so bear with me.

[Darren Abbey]

As much light as they can get will help… insufficient light will induce the plants to stretch out as they try to grow quickly towards what light is available. This is the motivation for keeping fluorescent light fixtures close to the tops of seedlings.

...but one aspect that is often overlooked is plants' need for physical agitation.

Plants gown outside have the constant buffeting of wind and they grow stronger stems to deal with such stress. Those grown inside will generally find no wind and grow only the strength they need to remain upright.

You can correct for this by placing a reciprocating fan aimed to sweep over your seedlings. I'm planning to place a set of small computer fans around my seedlings. (I like to tinker.)

[kayrobbins]

Darren Abbey is right about needing to simulate wind to make stocky plants. I have heard it referred to as manual manipulation. I don't use a fan but every day I brush my hand across my plants. Everyone always asks me why my plants have such stocky stems and I think that is the reason.

[Farmette]

How old should the seedlings be before you put the fan on them?

[RootLoops]

are you talking about the nursery grown tomato plants that are maybe 6-8" tall but the stems are big as a preschool pencil? i don't know for sure but i figure those are grown from cuttings and not seed. that way you could easily get a short plant with a nice thick stem. i could be wrong but that would seem like the easiest way to achieve that goal

[Pappi]

It is indeed agitation(wind or otherwise), ample light, and proper nutrients that does it. That's what gives you the stout thick stemmed transplant with lush green foliage. Helps to fund our SAR budget every year selling these type of plants. Makes the difference between people coming by to just buy a plant out of support and people actually putting in an order a half year in advance. People don't want to buy a plant that doesn't look healthy even if it's to support something.

As for nursery starts they do it the same, no cuttings/sucker/clones. Each operation varies between starting in six packs to dense planting then up potting. Two seeds to a cell is common, that's why you often have a second plant growing in the same cell/pot, they don't cull.

For the home gardener it's often easiest to have a light, fan, and dilute liquid nutrients. To each there own really and I find it usually comes down to your level of dedication to raise good starts. I participate in a few seedling swaps and I would say the majority are usually off color very tall plants with skinny weak stems and sparse foliage. There are even a few of those people who comment about how tiny my plants look, but the majority just want to know how to grow them. Anyway, I have a tendency to rant so...

Pappi

[RootLoops]

good to know! i wondered myself what caused that i'm gonna add an oscillating fan in as soon as i can

[beeman]

I was talking to our local nursery about the gorgeous plants they were selling last year. Seems they temp treat them.
She explained that day time temps were kept fairly low by ventilating the greenhouse while still snow on the ground. Then at night time they raised the temp to 70 degrees. Seems they have a different growing rate in the dark!
Best, strongest tomatoes I have ever seen. Will be trying it myself, soon as these Arctic lows have finished.

[dpurdy]

Originally Posted by beeman

I was talking to our local nursery about the gorgeous plants they were selling last year. Seems they temp treat them.
She explained that day time temps were kept fairly low by ventilating the greenhouse while still snow on the ground. Then at night time they raised the temp to 70 degrees. Seems they have a different growing rate in the dark!
Best, strongest tomatoes I have ever seen. Will be trying it myself, soon as these Arctic lows have finished.

barryla61,
beeman's answer is very close to what I do. I've found that temperature is as important as the light source. I don't exceed 70 degrees in my nursery room. The growth rate is slowed down, plants are much greener, and plants have thicker stalks. I'd much rather have a twelve inch stocky plant with a good root development, than the 18 to 24 inch tree-like plants that I used to grow. I try to maintain a temperature range between 65 to 70 degrees in the grow room. If your using florescent lights, try to keep them between 2 to 4 inches above your plants.
dpurdy

[Tom A To]

In addition to what is mentioned above, I would pinch the plants above the fourth set of new leaves. This puts energy into the roots, stem and stimulates new shoots.

Also, when weather allows, get them outside as much as possible to begin the hardening process. That will get them the light and agitation they need.

[madddawg]

Originally Posted by Farmette

How old should the seedlings be before you put the fan on them?

I would like to know that answer too.

I also temp treat them. I let the garage cool down to the 60s during the day then fire up the stove at night and get it up into the 70s. Then let the fire burn out overnight. and repeat the process the next day.

[Tom A To]

I am not a tomato scientist nor do I pretend to be one but I think tomatoes are not nearly as sensitive to temp changes as they are to UV light. The hardening process has more to do with that kind of conditioning. There are extremes however.

I also don't think it's necessary to put a fan on tomatoes although many certainly do. My stems turn out very robust with the jostling they get as I manhandle them in and out of the greenhouse as often as possible to condition them at the earliest age. If you aren't moving the plants in and out like I do, just shaking the table or bench they are on will suffice, in my opinion.

I would think that moving air evaporates the water from the starting mixture faster.

[Darren Abbey]

Originally Posted by Tom A To

I am not a tomato scientist nor do I pretend to be one but I think tomatoes are not nearly as sensitive to temp changes as they are to UV light. The hardening process has more to do with that kind of conditioning. There are extremes however.

I've been thinking of including a black-light in my seedling lighting setup for just this reason. I haven't heard of anyone experimenting with it, however.

[Doug9345]

I don't think a black light emits the right UV.

[Darren Abbey]

Originally Posted by Doug9345

I don't think a black light emits the right UV.

A good point. I should be able to get UV-C bulbs, but it would be an experiment in either case. I haven't read anything about what frequencies tomatoes use to trigger their intrinsic sunscreen. If UV-A (blacklight) is able to do it, all the better, since UV-A bulbs are easier to get and work with.