Can Leggy Seedlings Be Saved? (Yes, Here's How!)

Legginess happens to the best of us. It is one of the most common problems when starting seeds indoors. Whether you are brand new to seed starting or you are an experienced seed starter, at some point, you are likely to run up against this problem. The question, when you do, becomes

Can I save these leggy seedlings?

Jump to:

• Can Leggy Seedlings be Saved?
• What is Legginess in Seedlings?
• Why is Legginess a Problem?
• How Leggy is Too Leggy?
• How Do I Fix Legginess in Seedlings?
• First, Fix What Caused the Legginess
• Potting Up is the Best Way to Correct Leggy Seedlings
• Know when it’s okay to pot up seedlings
• Keep Conditions Right to Stop (and Prevent) Leggy Growth
• Vigilance is Key to Continued Success
• Ways to Encourage Stronger Stems
• Correcting Legginess in Older Transplants
• Catch and Correct Legginess and Have a Great Gardening Year

Can Leggy Seedlings be Saved?

Fortunately, the answer is usually “Yes.” With a little effort, leggy seedlings can be saved in most cases. At the very least, it’s usually worth trying, unless that legginess has just gone too far.

What is Legginess in Seedlings?

Legginess is when seedlings grow far too tall and cannot support proper growth and development. Instead of growing stout stems and beginning to form close to the soil line, the little plants shoot up and grow long, lanky, thin, stems that are unable to support leaves, foliage, and mature plant development.

Signs of legginess in seedlings include:

• Long stems, much longer than they should be for the type of seedling you are growing
• Very thin stems, not much thicker than a piece of thread; thinner than a length of string
• Stems that don’t appear to thicken and color as the plant grows
• Pale-colored stems
• Stems that bend, often curving up from the bottom with part of the stem laying across the soil
• Plants that loop, curl, or bend in the middle or top part of the seedlings
• Seedlings with pale, thin, small leaves, smaller than what you would expect for the type of seedling
• Seedlings that break because the top leaves are too heavy, or they are too tall with no lower support
• Seedlings that grow a lot of stem length before they grow true leaves

Why is Legginess a Problem?

Legginess is a problem for a few reasons:

• It invites disease and makes seedlings more prone to things like damping off disease
• It creates weak plants
• Stems cannot support the weight of foliage and break, which causes death to the plant because it cannot continue to feed itself
• Seedlings that do survive are too weak to live outdoors when transplanted
• Plants will not form properly
• Seedlings are stunted and weak and struggle to produce
• The stems cannot get enough food, water, and nutrients to the leaves, and the plant ends up dying
• Plants easily break when handled, blown, or jostled

How Leggy is Too Leggy?

Again, just how leggy a plant is before it reaches the point of no return depends, in part, on the type of plant and how long the leggy stem is. It also depends on how well the plant will respond to corrective measures, which depends on its growth structure and type of root development.

For most seedlings, if their stems are thready, thin, and longer than one to two inches before they start to form true leaves, they are leggy and need to be addressed. Keep in mind, though, that this is different for different types of plants.

A lettuce plant, for example, would be considered leggy if it has much more than a half an inch of single stem before leafing and branching, while a tomato seedling can reasonably have an inch or more of stem before it starts to grow true leaves. The more plants you grow from seed, the better you will get at spotting legginess. If in doubt, though, you are better off erring on the side of caution and taking steps to prevent or correct legginess as soon as possible.

You will generally know a leggy seedling is beyond repair if:

• It is three or more inches long before leafing
• Stems bend, twist, or loop
• Stems travel across the soil before they head upwards
• Stems fall over from the weight of growing leaves
• Stems are breaking
• Stems are pale and light in color, almost transparent
• Leaves are pale and look malnourished

How Do I Fix Legginess in Seedlings?

There are a few steps you’ll need to take to fix your leggy seedlings, starting with correcting whatever it is that is causing your seedlings to grow leggy.

First, Fix What Caused the Legginess

Legginess is almost always a light issue, but there are some other things that can either cause legginess or contribute to it and make the matter worse. The first thing to do is address the light issue, and then move through the list to see if any of these other causes are the cause or are contributing factors:

-Light Management: Light is either not strong enough, not the right type, is too far away (the usual culprit), or not available for enough hours of the day. Very few homes have enough light from windows to start seeds without them becoming leggy. You need a good set of grow lights. Grow lights need to be full-spectrum, and they need to be on for about 14 hours each day. They also need to be close (for most lights, they should be kept two to three inches above the tops of the plants).

-Temperature Control: Most seedlings are happy in the 65- to 75-degree Fahrenheit (18 to 14 C) range. If they are hotter than this, they may grow leggy. This is especially true if the soil temperature is high. A common mistake is to leave seedling trays on germination mats after the seeds have sprouted. This is unnecessary and often leads to legginess. Once seeds have germinated and pushed through the soil, take them off the mat. If they are too close to a hot heat source, move them or reduce the room’s temperature.

-Moderate Fertilizers: Overfertilizing can cause seedlings to grow too tall too fast, putting too much energy into stem growth and not enough into development. Seedlings will do better with some fertilizer, but don’t overdo it. You should hold off fertilizing at first, then start with a diluted strength, and then maintain a weekly schedule. Here is more on how and when to fertilize seedlings: including a week-by-week schedule.

-Good Watering Practices: Insufficient and inconsistent watering can lead to legginess and poor leaf growth, which also affects how the plant uptakes water. Water regularly as needed and always bottom water. Spritzes and spray bottles are not a guarantee that your soil is getting wet all the way through. Check plants daily to see if they need watering, but only water when needed.

-Avoid Overcrowding: Overcrowding means that plants are shading each other (yes, even as small seedlings) and fighting for light. This forces them to reach up to find the light, and the seedlings become leggy as they try to outcompete each other. Space seeds out when planting in germination trays. Follow the packet’s recommendations for spacing. Then pot them up to one plant per pot or cell so they won’t have to fight each other for light and life.

Potting Up is the Best Way to Correct Leggy Seedlings

Most leggy seedlings can be saved by potting them up into deeper pots and sinking the long stems down into the soil. Tomatoes, peppers, broccoli, cauliflower, kale, and related brassicas usually do very well with this method, because they can grow roots from sunken stems. Lettuces and many other seedlings will usually tolerate it well enough if you pot up when they are small, and it’s always worth a try.

To pot up seedlings to correct legginess:

• Use pots or cell packs that are at least two to three inches deep (or deeper if your seedlings are bigger and very long).
• Put a small amount of soil in the bottom of the cell.
• Handle seedlings by the leaves, not the stems. Leaves are stronger than stems and have stronger points of attachment.
• Use a craft stick or something similar to gently pry up below the seedlings’ roots.
• Separate individual plants if planted together.
• Place the plant in the cell or pot, with roots on top of the bottom soil.
• If the soil pot is deeper than needed, hold the seedling up a bit and add soil around the roots.
• Fill the pot with soil, leaving a slight depression at the top so that water does not wash out of the pot when watered. Gently tamp the soil with your fingers to remove air spaces and make sure there is enough soil in the cell or pot.
• You can bury almost all of the stem, but do not bury leaves.
• Set the cell pack or pot in a tray of water and bottom water until the pack absorbs water all the way from the bottom to the top.

Not sure how to pot up seedlings? Here’s a guide on how to do it: How to Pot Up Seedlings and Transplants

Know when it’s okay to pot up seedlings

Ideally, you should wait to pot up your plants until they have at least one set of true leaves—not just their cotyledon leaves (cotyledon leaves are rounder, and most look alike no matter what the plant is). Once the plant has grown at least a set of true leaves (leaves that look more like the shape of the plant when it’s grown), it should have enough root system to survive and thrive when potted up.

It’s even better if the plant has started to grow a second set, but if the legginess is getting too bad, it may be better to pot up sooner than you normally would. When you’re trying to save plants from serious legginess, potting up a little early is usually better than waiting for bigger roots and true leaves. It is best if the roots are showing some branching, though.

Keep Conditions Right to Stop (and Prevent) Leggy Growth

Legginess doesn’t only happen when seedlings first sprout. Indeed, this is the most common time for it to occur, because new, young, sprouted seedlings will always be the farthest from the light, and they have such fast spurts of growth in the beginning that it is easy to miss the signs, making it easy for seedlings to get ahead of you.

However, transplants can still get leggy and stretched when they are several weeks old if they are starved for light or overcrowded, or overfertilized. Use the same good, steady care all the way through until it is time to harden off your transplants and plant them outside. Most importantly, don’t starve your seedlings for light, and continue to give them good care after you correct the initial legginess. Encourage stocky, strong growth as you grow your plants on.

Vigilance is Key to Continued Success

Some days our seedlings need extra care—like when they need to be watered or fertilized—and some days, they don’t need much more than turning on their light switch. But young seedlings grow fast, which means problems like legginess can crop up quickly. The earlier you catch it and correct problems, the better your plants will be.

Check and observe plants daily, even if they aren’t doing much, and even on days they don’t need to be watered. When seedlings first sprout, the difference of a single day in the dark can make them grow thin and anemic. That's not the stage you want to set.

Ways to Encourage Stronger Stems

There are a couple of common tricks that work well to encourage strong, stocky stem growth. You can (and should) do this at any stage, but this is particularly helpful for seedlings that have already gone leggy and need some correction.

• “Pet” your plants. Each day when you check your plants, brush your hand lightly over the tops of the leaves. Movement and vibration like this stimulate the plants to grow thicker stems.
• Create some “wind”. Put a fan blowing over or oscillating near your seedlings to create some wind and movement. In nature, wind stimulates stem growth in response to movement to keep plants strong. This is missing from indoor grow setups. The breeze doesn’t have to be strong—a little air circulation in the room from an oscillating stand fan or a small fan blowing across the leaf tops will go a long way. Just enough to know that the breeze is hitting the tops of the plants.

Correcting Legginess in Older Transplants

If your older seedlings are stretched and leggy (for example, transplants that are about ready to go into the garden), if there is a lot of distance between the bottom of the plant and the firsts sets of leaves, you can correct this in a similar way to how you correct young seedlings.

If you have more than two weeks before the plants can be planted outside, you will need to pot up your transplants into taller pots and bury the stems deeper in the soil.

If it is close to the time to plant your seedlings outside, harden off your transplants and then plant them in the garden, but plant them deeper than you normally would to take up some of the length and legginess. You can strip the bottom set of leaves to do this if you need to.

Catch and Correct Legginess and Have a Great Gardening Year

Legginess does need to be a death knell for your seedlings and transplants, especially not if you catch it and correct it early on. The cost of seeds and materials does not need to be lost, nor do you have to lose the weeks spent germinating and growing your plants thus far. Follow these steps, save your seedlings from legginess, correct issues, and go on growing. Your plants and your garden will thank you!