Q.Tomato Plants Spindly and High
I have started tomatoes from seed in my house and while waiting for them to be transplanted outside, they are getting very tall and spindly with very narrow stems. Can I cut the main stem back by about one third or so to try to limit the height of the plant and thicken up the main stalk?

Certified GKH Gardening Expert
Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-fertilizer.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/should-you-prune-tomato-plants.htm

plant the plant up to the first or second set of leaves, the part below soil will turn into root system within a week of transplanting ,