AboutMike Mascio Expertise I have been an avid gardener since 1985 and an AllExpert volunteer since 1998. I specialize in soil preparation, seed starting and plant propagation, flowers, vegetables, and general landscaping. I am a strong advocate of the square foot method of gardening and the use of organic controls for pests and diseases.
Question I was wondering how to get the flowers I grow from seed to stay relatively short and have thick stems like the ones from the greenhouses i used to purchase by the flat. This year I started petunias, impatients and marigolds, as well as tomato's from seed. All of them grew very tall with long thin stems, "leggy" i guess its called? I have been told it was because they grew too fast, but I dont know how to make them grow slower. Any tricks I should know? I started them in one of the small indoor greenhouses from lowes, and when warm enough moved outside. I live in Northern NY if it makes a difference.
Thanks
Ryan
Answer Ryan, leggy plants are the result of one of three problems. Either the plants are not getting the proper light, they are becoming root bound, or they need pinched to promote bushiness.
The ideal situation is to have them 3” below grow lights. I grow over 700 seedlings and hardly ever experience leggy plants. This is because I am constantly adjusting the fluorescent lights to stay just above the top of the plants.
In regard to lighting, gro-lights are the perfect fluorescent bulb because they most closely replicate natural sunlight. A less expensive alternative is to use one warm and one cool fluorescent bulb each as a set. These also will provide the proper spectrum of light.
Pinching is a simple process that entails pruning off the top set of leaves. Seedlings should never be pinched until they form their fourth set of leaves. At that time, they are mature enough to handle the shock. Pinching is a good practice to get into because it promotes a more bushier habit. I usually pinch mine two or three times before transplanting.
Once the seedlings reach maturity, they are ready to be placed outdoors, but the need to be slowly acclimated to the harsher conditions. This procedure is termed hardening-off. I recommend placing them on a protected porch or patio in indirect sunlight for 3 hours the first day. Double the time outdoors each day until they are out a full 24 hours.
They should then be able to be transplanted to the garden with no problem.
Also, check the root system to make sure the root ball is not overly bound or tangled. If it is, you need to transplant the seedlings to a slightly larger container.
I hope this helps. Good luck, and please write again if I can ever be of assistance.
