Why Seedlings Get Leggy. Fix Proven Issues To Succeed

It can be quite disheartening to garden with substandard seedlings, especially when they are delicate and thin. The long and slender stems or internodes of a seedling make them vulnerable to the severity of transplant conditions, decreasing their chances of favorable growth, and possibly leading to the demise of your vegetation. This might result in disordered, dense bunches of greens that detrimentally impact yield when cultivating your own food.

Why do seedlings get leggy? There are several reasons seedlings get leggy. But the most likely is lack of light. The seedling is in the growth phase and is searching for a better light source. Providing adequate light levels at the proper range and spacing when your seedling germinates is essential.

The Advantages Of Starting Seedlings

The advantage of indoor seed-starting cannot be denied. For one, it gives you complete control over the varieties and types of crops you grow. It also gives you control in terms of how the plants get produced. However, growing indoor seedlings does come with maintenance.

They are not unlike babies in which everything has to be just right. Without the right conditions, seedlings develop small leaves and pale stalks and grow thin and long instead of stout and robust.

Leggy Seedlings Equals Weak Seedlings

The weak stems can’t hold themselves up. They look like they are striving to grow because they are. Not only do they look unsightly, but this also means that when transplanted, they are unlikely to survive the outdoors.

Legginess means the seedlings aren’t storing as many carbohydrates. If plants are not getting sufficient sunshine or light levels indoors, they won’t be able to deal with the rigors of wind and sun.

Getting A Jump Start With Seedlings

Many serious vegetable gardeners start seeds indoors to get a jump start on the season for growing. In cold climates, planting seeds indoors assures that squash, zucchini, cucumbers, tomatoes, and other slow-maturing plants will produce fruit by midsummer. For flower gardening, this works too. Purchasing flower seeds is one practical alternative to buying younger annuals and perennials.

The Challenge Of Growing Seedlings

The only thing is that sometimes, starting seeds indoors can be fraught with challenges. The most common of which is that the seedlings turn out leggy. Even carefully sown seeds in the suitable soil, placed in a window facing south, diligently watched until germination and sprouting sometimes fall victim to spindly, weak stalks. Legginess is a pattern of irregular growth.

This is brought on by low light levels indoors. Even when in south-facing windows. Light levels are short in winter when most gardeners start their seed sowing. This can harm your seedlings if inadequate light levels are present.

This is not exactly healthy for your plants as they grow larger. The reason is that being leggy will make it unable to support its weight. Also, leggy seedlings face a significant challenge once exposed to outdoor elements. Ensure your indoor conditions create well-established plants that thrive well in a garden setting. This way, when you transplant them outside, they grow correctly and sustainably.

What Makes Seedlings Get Leggy?

Traditionally, legginess is caused by a lack of sunlight or light. When light is either indirect or too weak to meet the needs of the plant, what happens is that the stems grow thinly because the plant reaches its leaves towards the light desperately.

Seeds that start when the sun is low in the sky, such as in early spring or later winter, are prone to this growth pattern. Sunlight in these seasons isn’t strong enough to allow plants to grow, let alone thrive.

Prevention of Leggy Seedlings

To prevent seedlings from getting leggy, a few surefire methods are known to work. Here is a list that ensures you never have to transplant leggy seedlings.

  • Adjust Your Light Source When Seedlings Get Leggy
  • Use Artificial Light When Seedlings Get Leggy
  • Give Your Seedlings Direct Light
  • Remove the Competition When Seedlings Get Leggy
  • Seedlings Get Leggy From Overheating
  • Seedlings Get Leggy When There Is Not Enough Water
  • Check the Soil Ammonia Nitrogen Content
  • Thigmotropism

Adjust Your Light Source When Seedlings Get Leggy

Remember to keep your light source close enough to your seedlings so they never have to reach out to get it. Make sure not to cause the leaves to burn by keeping artificial light two to three inches from the top of your seedlings. If you place artificial light any further than three inches, the tiny plants tend to stretch themselves, becoming leggy.

Use Artificial Light When Seedlings Get Leggy

They are providing artificial light. You can use artificial lighting if no window anywhere near gives direct sunlight for seven to nine hours. Various grow lights specially made for growing seedlings are available at plant stores.

Of course, regular fluorescent shop light fittings with T5 bulbs will also do the trick. Use artificial light to provide at least sixteen hours of light on your seedlings daily. Get a timer to make tracking exposure time easier without any extra effort.

These days lighting technology has moved on in leaps and bounds. LED has dramatically improved, idramaticallyding the correct light levels for seedlings at affordable costs. I recently produced a video on one such unit that I love.

LED makes lighting so much easier and very economical on your energy bills. This unit is awesome for providing the required light and stopping leggy seedlings. The Spiderfarmer SF1000 available on Amazon is perfect for this task. You can see the video below.

Spider Farmer SF1000 Led Grow Light

Give Your Seedlings Direct Light

To prevent leggy seedlings, you will need to provide light directly. Just because it seems as if a window seems bright from appearing till sunset does not automatically mean that there is direct sunlight created for growing plants.

You need to place seedlings by a window that directly experiences seven to nine hours of sunlight daily. Even outdoor plants that thrive in partial shade during summertime need sunlight now for seedling propagation.

When sets of leaves are on the seedlings, they have a root system and have established themselves. Pinch off the top sets of leaves to train them to bush and to keep the plants compact. This will allow the stalk to thicken up and make for a much more robust plant.

Remove the Competition When Seedlings Get Leggy

When many seedlings grow together, they get big enough to begin shading each other at a particular stage. This forces them to compete for light and grow taller as a result. Rather than letting them get unnecessarily tall, adding light and transplanting each seedling at the right time when their actual leaves make an appearance is a solution.

If a particular seedling crop gets larger and begins to shade the others before the transplanting day arrives, you might consider using larger seedling trays and plugs to give each seedling more space.

Seedlings Get Leggy From Overheating

When seedlings overheat, this could cause a rapid spurt of growth that leads to becoming leggy. Germination requires warm temperatures.

However, most seeds grow optimally at sixty-five degrees Fahrenheit or around nineteen degrees Celcius in the daytime and at fifty-five degrees Fahrenheit, thirteen degrees Celcius at night. If you use a heat lamp and don’t realize it is too hot, the stems will grow faster than the leaves.

Seedlings Get Leggy When There Is Not Enough Water

Legginess can also be a symptom of not getting enough water. The same can be said for improper drainage and poor soil, which stunts seedling growth as they struggle to absorb nutrients and water. Ensure you are watering your seedlings in the appropriate amounts they need for proper development. Aim for damp soil, not moist. Water from the bottom is also much better for seedlings.

While talking about water, it is much safer to use tap water with seedlings than rain or well water. This will ensure no bacteria or fungus can cause issues at such a fragile plant life stage.

Check the Soil Ammonia Nitrogen Content

I am using different mixes of fertilizer results in ammoniacal nitrogen in varying amounts versus nitrate nitrogen. The plant uses nitrogen in the form of nitrates directly. This results in more compact growth. On the other hand, ammoniacal nitrogen produces leggy seedlings.

Fertilizers used in hydroponics hardly have any ammoniacal nitrogen since these are created to be available immediately to crops. Using fertilizer, you grabbed off the shelf, designed for farming or soil gardening, the urea contributes to the nitrogen. Switch instead to fertilizers for hydroponics. Check the label and ensure no ammoniacal nitrogen content or urea.


 Strengthen your stems through thigmotropism. This means stimulating the movement of environmental stress on your seedlings. In other words, you must mimic what goes on outside on your kitchen table. You can do this by putting a small fan beside your seedlings and time the simulation of your plants blowing in the breeze a few hours daily.

If you don’t have a fan or want to reduce energy, you can stimulate stronger growth by passing your hand over the seedling tops a few times daily. This will help the stems of each seedling become more robust and ready for the outdoors.

Preparing The Seedlings For Outdoors

One common beginner mistake many newbies make is sowing tender seedlings grown indoors directly into the garden as soon as the date recommended for planting arrives. This can be disastrous as the sudden environmental change can kill seedlings that have not been acclimated. To keep your seedlings alive, start by hardening them off before the date for transplanting arrives.

To do this, move them outdoors for a few hours daily when there are light breezes and mild temperatures. Please bring them back indoors to protect them from the cold night air at night. Gradually increase the amount of time they stay outside during the day. The seedlings will be tough enough to survive any weather inconsistency by planting time.

Can You Save Leggy Seedlings At Home?

Depending on the seedlings and their varieties, you can save some seedlings if they get leggy. Others maybe have to be consigned to the compost heap. The seedling that can recover from being leggy are:

  • Any of the Brassica Family
  • Tomatoes
  • Melons
  • Pumpkins / Gourds. Squash

The above seedlings can be transplanted much deeper, even up to the cotyledon leaves (Seed Leaves). This starts the process by giving you a very short plant. You can do this because these plants can either root from the stem or do not have problems with stems being buried. Be mindful of what seedlings you try this with thought, as some seedlings will rot off if you bury them deeper.

Pplantt When To Let Go When Seedlings Get Leggy

It can be heartbreaking for gardeners to cut their losses when it comes to highly leggy sehighlyThis is particularly true when they have become somewhat emotionally attached to their baby plants and did not expect to see their seedlings get leggy. The thing is, when they get too skinny, they really won’t do well outside anyway. You need to start over with new seedlings using the above guidelines.

When seedlings get leggy, you can’t create an un-leggy plant once they have grown past a certain point. The best thing you can do as a last resort is plant more seeds in a location full of sunshine. You can tell when your seedlings have passed the point of no return.

When leaning over and quite limp, they are usually past the point of being savable. This is when you must let go and start with a new batch.


Although it sounds complicated growing seedlings, it is well worth the effort. It allows you to get good yields of food or flowers from plants that wouldn’t usually have a long enough season to grow. By following the tips, I have given you above; leggy seedlings should become a thing of the past for you. Now you know these rules; you can get this season off to a great start with no worries.

I hope you enjoyed this blog post about leggy seedlings. I trust it answers your question fully. If this interests you, why not consider subscribing to the blog so you don’t miss future content?

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And remember, folks, You Reap What You Sow!

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