I'm in zone 5 Indiana. The tomatoes have been in the garden just one month (since last freeze) and now have blooms. They look very healthy (used some composted horse doo-doo) and are knee high. I hope the early blooms don't abort like they did last year!

It can be genetic. There are varieties that have the precocious flowering trait that will always set flowers by the 6th of 7th leaf stage. It can be physiological. If the plants are kept root bound but have plenty of nutrients, it will induce early flowering. It is NOT caused by cold weather. In fact, cold temperatures slow down seedling growth so much that they won't set flowers until the cold shock has been offset by much warmer weather. Cold temperatures within some limits are beneficial to tomatoes. You can search and find studies where tomatoes exposed to cold temps for about 2 weeks produce more flowers and set more fruit. Regardless of why the plants are flowering, I would pull off any flowers or fruit until the plants have been in the ground at least 3 weeks. Plants that try to support fruit load any earlier don't have a root system developed enough to continue growing at the same time. As a side note, the most beneficial thing you can do to a tomato seedling is to semi-starve it for water. The plant will develop a much larger root system. This pattern of growing more roots will continue even after the plant is transplanted into the garden. These plants will produce a larger crop because the root system is larger. Darjones

This year i have two each of 8 varieties. I picked the flowers off half of them. so far there is no noticeable difference in plant growth (both are thriving) and a few of those original flowers set fruit and are sizing up nicely. Others seem to have aborted. Since it doesn't seem to have affected their initial growth I will probably leave the flowers on in coming years, but I may do the same thing next year as a second test. The varieties I planted are below. All had flowers or buds when I transplanted them on May 3rd. Cherry Roma (seemed to abort many of the early flowers, but there are a few tiny fruit). Park's Whopper (seemed to get fruit from all (most?) early flowers and is sizing up nicely), Black Krim (some fruit) German Pink (No fruit yet) Marianna's Peace (no fruit yet) Kosovo (some fruit and sizing up very nicely. this one might be my surprise winner for early toms) Opalka (no fruit yet) Italian Heirloom (most flowers seem to have aborted but I have one tomato) Those that I pinched the flowers off have no fruit but have lots of new flower/bud trusses (trusses?) so, even though the growth seems to be similar, perhaps they will set more fruit later in the season. But, I really haven't paid close attention to which ones have the most flowers. I suppose time will tell. -jon ps. i really appreciate all of the regular responders on this forum. I have learned so much. thanks.

I wouldn't want my 12" plants blooming (even though they would already be in the garden for me if they were that tall) so I would remove the blooms. How long until you can plant them in the garden? Dave