How To Save Leggy Seedlings

How To Save Leggy Seedlings
If you happened to get started early with your seeds this year, it’s likely about this time where you could be facing the problem of leggy seedlings! 

Leggy seedlings are those that grow tall and spindly with thin stems and small leaves due to a lack of sunlight. Below is a picture of a tomato plant I started from seed this year that is getting a bit too stretched. It is not the best example, as there can be much worse cases than this!

After putting all the effort into sowing the seeds and minding the seedlings to this point, I’m sure the last thing you want to do is get rid of them just because they’ve become weak.

In this post, we’ll look at a few things you can do to save leggy seedlings.

1. Transplant Into Larger Pots
If your seedlings are already leggy and drooping over. Transplanting them to larger pots is the first step.
Along with a stretched and weak stem, seedlings have shallow root systems, which makes them unstable.
Transplanting them into larger pots will give them more room to grow and will provide them with more stability.

When transplanting them, bury the stem right up to the first set of leaves, the part of the stem you bury will put out new roots from the stem. With tomato plants, if they have become really leggy, you can even clip off the first set of leaves (cotelydon leaves) and bury the stem all the way up to the first set of true leaves. This will provide the plant a lot of stability, and help it to stand up straight again.

When transplanting, fill the bigger pot up with compost and make sure you make a hole in it that is deep enough that you will be able to bury the long stem.


With tomato plants, you can do this multiple times when repotting them as they grow. In the picture below, you'll see a tomato plant I grew last year. When transplanting this one into its final pot/bucket! I cut off multiple sets of true leaves, allowing me to bury a lot of the stem, which then produced lots of new roots. The plants I did this with were really strong.

2. Give Them More Light
After transplanting, you’ll want to give the seedlings a new light source. The main reason for leggy seedlings is lack of light. When your seedlings don't receive enough light, they stretch towards the light source they have, making them tall and thin. This happens when we grow seedlings inside for too long.

If you're using artificial light, make sure that the lights are close enough to the seedlings. Most seedlings need at least 12 hours of light per day. If the light source is too far away, the seedlings won't receive enough light, and they'll continue to stretch towards it.

If you're growing your seedlings near a window, make sure that they receive plenty of direct sunlight. Rotate your seedlings regularly to ensure that all parts of the plant receive equal amounts of light.

3. Harden off Your Seedlings
The best thing to do with seedlings now is to harden them off before putting them outside for good, so they can receive more natural light.

Hardening off is the process of gradually acclimating your seedlings to outdoor conditions, such as sun, wind, and temperature fluctuations. It is a good bit of work, but worth it.

Start by placing your seedlings outdoors in a sheltered area for a few hours each day. Gradually increase the amount of time your seedlings spend outside each day, and gradually expose them to more sun and wind.

Be sure to keep an eye on your seedlings during the hardening-off process. If the weather is particularly windy, you may need to bring your seedlings indoors to provide them with shelter. Do this for about 2 weeks.

Hardening off your seedlings can help to prevent transplant shock and prepare them for life outdoors. By gradually acclimating your seedlings to outdoor conditions, you can help to ensure that they grow strong and healthy after transplanting.

4. Give Them Support
Lastly, If the seedlings are very weak even after burying the stem during transplanting, you may need to provide them some support with a cane or stick. This will help to keep your seedlings upright and prevent them from breaking. Place the support close to the seedling and tie it loosely to the stem. This will help the seedling stay upright and grow straight. Make sure not to tie it too tightly, as this could damage the stem.

In conclusion, to save leggy seedlings:

1. Transplant them to a larger pot to bury the stem and provide support.

2. Try and give the seedlings more light, as the lack of light is the cause of them being leggy.

3. Harden them off so they can be left outside, or in an unheated greenhouse where they will get more light.

4. Support the seedlings to prevent them from breaking.

I hope you might have found this useful, and hopefully it might give your seedlings a second chance if they have become leggy!