what are leggy seedlings?

Seedlings sometimes get very tall, with weak skinny stalks and leaves up high. These are 'leggy' seedlings. Legginess occur most often when seedlings are not getting enough sunlight. 

The first leaves that emerge from the seed are called cotyledons. They are a part of the seed's embryo, and provide the first nutrients to the seedling until the plant's true leaves start to grow. They are reaching for more light and to ensure the plant has enough nutrients, making them tall and skinny, instead of short and lush.   

For a densely planted baby greens garden, leggy seedlings aren't a big deal - the plants will still grow baby greens, though they may be slightly weaker and smaller. But if you are planting seedlings indoors for transplant later, like tomatoes, peppers, and others, leggy seedlings can mean weaker plants with lower success rates later.

This side-by-side comparison shows kale seedlings that are not leggy (left) and leggy (right). They were planted on the same day, and given different amounts of light.

here's what you can do about leggy seedlings

NOTHING. 

For baby greens gardens, leggy seedlings are ok. Not ideal, but if you just can't find more sunlight, they'll still grow!

THIN OUT SEEDLINGS. 

This is especially important for the seedlings you start indoors to transplant outside. Gently remove seedlings to reduce the density, so the plants are not all competing for the same limited light. You should have 1-3 seedlings per grow pot. If you are growing seedlings in a flat container (no individual pots, one larger shallow grow space like a berry container or other plastic flat) space your seedlings out so they are 1-2 inches apart. 

MOVE SEEDLINGS TO BETTER LIGHT. 

This is the most important solution. You can do this by moving your seedlings to a sunnier window. South and west facing windows are best. I put my seedlings outside during the day when it's warm out, and bring them back inside at night to avoid cold weather and frost.   You can also invest in an indoor grow light if you do not have other options for sunnier windows or access to the outdoors. Follow grow light instructions for best results. 

MOVE SEEDLINGS INTO A NEW POT + BETTER LIGHT. 

If it's too late and your baby peppers or tomatoes look leggy beyond repair, there still may be hope. You can transplant your seedling to a new, slightly larger pot. When you transplant, plant the seedling deep so that the soil comes up almost to the first leaves. This will encourage the plant to grow new roots. Allow the plant to continue to grow in good sunlight for at least another 2 weeks before transplanting into a garden.