How to Save Leggy Tomato Seedlings? Garden Tips 2024

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Tomatoes are a great starting plant for any beginner. You can plant the seedlings indoors early and then transplant them to your garden once the weather has warmed up. Unfortunately, tomato seedlings may become leggy, but here’s how you can save them.  

How to save leggy tomato seedlings:  When tomato seedlings are too crowded or aren’t exposed to enough light, they can become leggy. Start by repotting your seedlings and burying the stem up until the first set of leaves. The stem has tiny root structures that will grow under the soil to strengthen the plant. Space the seedlings out so they aren’t competing for sunlight and always use new potting soil that is full of nutrients.

What is a leggy tomato seedling?

All seedlings can become leggy at some point but it does seem like tomatoes are more prone to this condition than others. After the seed sprouts, it will grow up through the soil as it reaches for more light.

In ideal conditions, a seedling will have multiple pairs of leaves along its stem. However, leggy tomato seedlings will have a long, bare patch of a stem with only a few leaves at the top.

The problem with any sort of leggy seedling is that plants need more leaves in order to absorb sunlight and store energy. Furthermore, leggy seedlings are a sign that there is a problem that may stunt the growth of the plant or even prevent it from surviving.

What causes leggy tomato seedlings?

Not enough sunlight

Seedlings grow upward to get to a light source. If that light source isn’t immediately available, they will keep growing, but at a quicker rate than the growth of their leaves.

You might think you have placed your seedlings near a light source but this might only be for a few hours in the afternoon, which isn’t enough. Hours of sunlight are especially a problem in the winter as there are fewer daylight hours and more cloud coverage.

The direction of the sunlight can also be a factor. Seedlings can actually move throughout the day, chasing that light source.

Not enough space

Even though seedlings start off tiny, they do need enough space to grow. This lack of space can affect the plants both below ground and above ground.

Crowded root structures may result in the seedlings putting too much energy into their stems, which causes legginess. However, if the roots aren’t strong enough, the plant can topple over or not receive enough nutrients from the soil.

Above ground, overcrowding can create shadows that limit the amount of sunlight the seedlings can get. If you have a wide seedling tray, the plants at the back may be continually cast in shadow.

How to save leggy tomato seedlings?


It’s not too late to save leggy tomatoes and the easiest method is to repot them. Spread the seedlings out so they aren’t competing for space. The new soil will have fresh nutrients which will help the seedlings grow stronger.

When replanting, bury the seedlings up to their lowest set of leaves. Unlike other plants, tomatoes have the ability to grow roots, even from their stems.

As the long stems are placed underground, the tiny root structures along the stem will grow larger, which will then strengthen the whole tomato plant.

Add a light source

If your notice that the window you initially placed your tomato seedlings next to was not providing enough light, then you might want to install a grow light. These emit continuous light and you can angle them so they shine directly down on the seedlings.

Provide space

As we mentioned in the repotting section, your seedlings need space and when you repot them, be sure to spread out the seedlings. This can be hard if you have limited space but is important if you want your seedlings to recover.

Some gardeners will actually repot their seedlings two or three times before they transplant the seedlings to the garden for good. Again, this can be hard work but is important if you want to allow the plants to keep growing as they mature.

How to prevent leggy tomato seedling

Watering schedule

Tomato seedlings prefer slightly moist soil. When the soil dries out, the seedlings slow their growth, and then when they get water, they grow too quickly.

You want to stick to a consistent watering schedule. Test the soil every few days with your finger to ensure it is moist but not soggy.

You can also try bottom watering where you place a seedling tray into a larger tray of water. Then, the water is taken in from the bottom up for more even absorption.


Knowing that seedlings will grow quickly, don’t start them off in large clumps. Stick to proper spacing with seedlings so you can go longer before repotting them.


Seedlings need a good, all-purpose potting mix to start with. This will have the right nutrients for the tiny plants to grow and thrive.

Don’t use the old potting mix as this has the possibility of being moldy. Instead, always start with new soil when you first plant.


Placing seedlings near a window is the most common location. However, windows can be quite cool, especially in late winter and early spring when you plant seedlings.

Move the trays away from the windows so that they still get the benefit of light but aren’t exposed to the cold glass.

Avoid placing seedlings anywhere that is drafty or has extreme temperature changes, such as if the heating is turned off at night.

You can always invest in grow pads that heat the bottom of seedling trays or grow lights. If you have a grow light, you don’t have to worry about keeping your seedlings near a window.


While leggy tomato seedlings can result in stunted growth and lagging development, if you catch the problem early you can correct it. Repot your tomatoes in fresh soil, ensure they have enough light and regular watering and watch for success.

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