READ the back of the seed packets. LOTS of info there as to when and how to plant.

Too early? Well peppers can be started much earlier (8-12 weeks) than tomatoes as they are much slower to germinate and to grow. Tomatoes are normally started approx. 6-8 weeks prior to your transplant-to-the-garden. You can stretch that to 10 weeks with multiple potting-ups to larger containers but after that, even if they don't get root bound, they start to get too big to tolerate transplanting as well.

A 6-10" transplant is considered the ideal size for tomato plants; a bit larger for peppers. When one gets into 12-20" plants the root system has difficulty supporting the top growth and the plant is much more heavily stressed by transplanting; takes it longer to recover and is susceptible to pests and disease during that recovery period.

Dave

I am assuming that the time on the packs is minimum to transplant. I've seen (and bought) very large plants from nurseries that obviously not the minimum growth listed on seed packages. What I am asking is do others grow for longer periods to get larger plants? I'm in the Buffalo are so we have a realitivelt short season. I am not assuming the seed packets tell you EXACTLY when to plant/

What I am asking is do others grow for longer periods to get larger plants?

Given the many posts here and on other forums about starting their seeds now or 'already started' regardless of their zone, yes, I'm sure they do. Everyone gets antsy to start and as long as you can cope with all the potential problems then give it a try. It is a good learning experience and about all it costs you is some seeds and your time.

I understand your concern about the short growing season but please understand that many studies show that (1) using large plants for transplanting doesn't equate with earlier production and that (2) standard 6-10" transplants quickly catch up with and even surpass extra large transplants.

But go for it. It is the best way to learn what works best for you.

Dave

DBA,

You are correct, with your better lighting you could start earlier than the recommended times and set out much more advanced plants. In past years I have set out tomato, pepper, and eggplant plants that were in bloom and with small fruits set on them, using overdriven fluorescent shoplights as my light source for no more than 1000 foot candles on the leaves. That is less than 20% of full sunlight outside. (Full sun can range from 5000 foot candles to 8000 foot candles). Your lights are probably much better than mine.

If you do plan to set out much larger and more advanced plants, you will need to re-pot them to larger pots as your plants outgrow the pots they are in. I start my plants in 3.25-inch square pots, re-pot to 5-inch square pots, and re-pot again to 8-inch square pots.

If you are growing your plants in a soilless growing medium (I use Premier ProMix BX), you will also need to water your plants with a dilute but complete nutrient mix. The ProMix that I use does contain enough calcium to get the plants beyond the seedling stage, but by the time they start to bud out, the calcium is depleted and the plants start to suffer calcium deficiency symptoms. To prevent that, I add a little calcium nitrate along with the other soluble nutrients. Hydroponic growers always supply calcium nitrate in their nutrient solutions, and you will probably purchase yours from a hydroponics supplier. Calcium nitrate is an inexpensive soluble nutrient.

Actually, if you think about it, growing plants indoors in a sterile growing medium is, in effect, a form of hydroponic gardening. You are just using a different root support medium instead of soil. Hydroponics is defined as "a technology for growing plants in nutrient solutions (water containing fertilizers) with or without the use of an artificial medium (sand, gravel, vermiculite, rockwool, perlite, peat moss, coir, or sawdust) to provide mechanical support."

You might want to use soluble nutrients that do not contain urea as a nitrogen source. Most plants can absorb urea through their leaves as a foliar feed, but apparently not through their roots. Their roots can take in nitrate ions or ammonium cations. There are several sources of urea-free soluble plant nutrients. I use Better-Gro Orchid Plus and Better-Gro Bloom Booster. I usually purchase my Better-Gro nutrients at a local Lowe's Home Store to avoid paying shipping. There are other good urea-free nutrient formulas in the marketplace. But I am in a Lowe's store from time to time anyway, so it is handy for me to pick them up there.

ZM
(not associated with any product or vendor mentioned or linked)

In addition to all the great info shared here, it's been our experience that when it comes to tomatoes, the best seed starting date is 6-8 weeks before you set them out in the garden. Plan to put them in the garden 10-14 days after the last frost date (tomatoes don't like to be cold.) As an example, if your last frost date is April 15, then start tomatoes around March 1. Set them in the garden in late April or early May.

Here is a link that might be useful: When to start tomato seeds