Long, Thin Stems on Seedlings

Q. I planted cauliflower and spinach seeds indoors about 4 weeks ago and my seedlings have 6 inch skinny stems with small leaves at the ends. I don’t think the stems are supposed to be long and thin like this — why are my cauliflower and spinach plants growing so long and skinny and not looking like the seedlings I see in nurseries?

A. You must give seedlings maximum light for 14-16 hours each day IMMEDIATELY when they emerge.  Otherwise their stems will stretch and become long, thin, and weak as they search for the essential light they must have in order to photosynthesize and live.  This is the main reason most people have poor success in growing their own seedlings.  Maximum light in someone’s house does not mean a window sill that gets direct sunlight 2 or 3 hours each day.  You need 4-foot shoplights with one cool and one warm bulb, or the more expensive “grow-lights”, and they should be no further than 3 or 4″ from the plants.

Even a few hours will make the difference between healthy plants with sturdy thick stems and ones that are weak and spindly.  Nature’s laws are simple, but immutable, and you must obey or pay the price.