Leaves drying on seedling ends and falling off

by Deb T.
(near Denver, CO)

A. I have a unique situation where I bought a LED grid light this winter and planted indoor tomato seeds on January 15. Now, eight weeks later, I have six plants that are about 2' tall, some already producing fruit. Only one plant is having a problem. The ends of the leaves and drying and curling. They are still green, not turning color. Then the whole leaf falls off the stem. I do need to re-pot all of them. They are in brand new Miracle Grow soil and there are no insects. I keep the plants in my guest bedroom and all the tomatoes are treated the same. I'm just curious what could be causing problems for this one plant. It's Beefsteak, the seeds came from a package.

A. You didn't mention how close you have set the plants to the lights. When tomato plants are too close, leaves can curl, develop brown edges, or become damaged.

Further, your plants at 8 weeks old most definitely need to be re-potted ... in fact, at that age, it would be time to set them in the garden (if outdoor temperatures were cooperative.) Plants are likely stressed. As you re-pot you will see the root system. Hopefully the plant is not root-bound. Set the plant in the largest pot possible until it is time to harden it off into the garden. More room in the pot will reduce its stress, allow the roots to spread their wings, and let plant absorb enough water to sustain itself until it goes into the garden. Bury the stem as deeply as possible.

In a small container, the plant also is likely struggling to get adequate food. Water it with a one-quarter or one-third strength fertilizer solution. Your photo shows plenty of new growth in suckers at branch intersections. The plant also looks a bit leggy. Those factors together tell us that the plant is reaching up to the light (and is eager to get outdoors) and that it is in need for additional nutrients.

Good luck and happy gardening!
Your friends at Tomato Dirt