I start my tomato seeds indoors, with fluorescent grow lights about 24″ above the trays. Every year, the seedlings grow tall and spindly, and they’re very fragile. What should I do? -David
The main reason for tall, spindly tomato seedlings is a lack of light. As the plants strain toward the light, they grow taller, thinner, and more fragile. To help with this, you can:
- Increase Light: Lower your light fixtures, increase the wattage, or raise your trays to get them closer to the light source.
- Provide Sunlight: Grow lights are great, but they’re no match for pure sunshine. As soon as the weather allows, move your plants to a spot with plenty of natural sunlight, even if it’s an indoor window.
- Encourage Branching: Pinch back the tops of your plants as they grow, to encourage them to branch out.
- Transplant Correctly: When you transplant your seedlings into the garden (or into pots), plant them deeply so that at least half to two-thirds of the stem is buried. Some gardeners bury tomato plants all the way up to the topmost leaf cluster. The spindly stem will sprout roots and become part of a deep, strong root system, and the top part of the plant will quickly grow to make up for it.