How to Fix Overcrowded Seedlings in 5 Easy Steps
Did you start too many seeds and end up with overcrowded seedlings? Join farmer Briana Yablonski to learn how to give your tiny plants more room to grow.
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Starting seeds is always an exciting process, but sometimes, our enthusiasm can harm the health of our plants. If you’ve planted too many seeds in a small space, you’ll likely end up with overcrowded seedlings competing for water, nutrients, and light—thankfully, this can quickly be fixed.
If left alone, these seedlings will have a difficult time obtaining all the resources they need to grow into healthy plants. Crowded plants also experience limited airflow, so they’re more likely to develop diseases.
Instead of letting your seedlings grow into scraggly plants, you should take steps to give them the best shot at becoming healthy transplants. Fortunately, you can help your plants by following a few simple steps. I’ll explain how to fix overcrowded seedlings in under an hour.
Assess the Situation
Since spring is such a busy time in the garden, I try to stay away from unnecessary work. So, before you assume your seedlings are too close together, ask yourself some questions.
What Type of Container Did You Use?
First, look at the type of container the crops are growing in. Did you plant them in an open flat with the intent of later up-potting them to single-cell trays? Or did you sow too many seeds in a single cell?
If you’re growing in an open flat to save space, that’s great! I often plant my pepper and tomato seeds closely together in a tray so I can fit all my heat-loving seeds on heat mats. However, once the seeds germinate and develop some true leaves, it’s best to move them to individual containers before planting.
If you started the seeds in individual cells, you probably didn’t intend to move them to other containers. However, you may plan on bumping the plants up from a small cell to a larger pot.
How Many Do You Need?
When it comes time to give your seedlings more room to grow, you have two main options. You can separate them and plant each one in its own cell, or you can cut some of them near the soil line.
Determining how many plants you need will help you determine the best option for you. For example, let’s say you planted two four-cell trays with tomatoes. You weren’t sure about the seed’s viability, so you planted three tomato seeds per cell.
Well, it turns out the seed viability was great! All but one seed germinated, leaving you with 23 baby tomatoes. If you think you can use extra seedlings, moving the extras to their own cell is the right call. However, if you only have space for 8 tomato plants, you can snip the extras when they’re still young.
Removing Unwanted Seedlings
If you decide you want to get rid of unwanted seedlings, the first step is identifying the healthiest specimens you’d like to keep. You can complete this process any time, but it’s easier to remove unwanted sprouts when they’re small because you won’t disrupt the root zones of those you wish to keep. I recommend waiting until they have one set of true leaves.
Remember, the tallest sprouts aren’t always the healthiest! Look for sturdy stems, green leaves, and overall vigor.
Once you’ve determined which tiny plants you’d like to get rid of, grab a pair of sharp scissors or knife and cut the unwanted sprouts just below the soil surface. Gently remove the unwanted stems from the container to allow the remainder to flourish. This is the quickest and easiest fix for overcrowded seedlings!
Remove From Their Container
Removing and disposing of extra seedlings is a pretty simple process. However, separating and up-potting the seedlings into their own containers is a bit more involved. From this point on, this is the process I’ll explain.
If you decide you have the number of seedlings you want, but the crops are too crowded in their container, your first step is to remove them from the container. I recommend waiting until they have one or two sets of true leaves.
The container type determines the best way to remove them. If you’re growing in cell trays with holes in the bottom, gently poke the bottom of the soil with your finger or a stick until the entire soil block loosens. Then, you can gently grab the sprouts and pull them out of the container.
Pro tip: Always handle seedlings by their cotyledons rather than true leaves or stems. If the cotyledons break, the seedling will survive and continue to grow.
If you’re working with a larger container or open flat, you won’t be able to poke the soil from the bottom. Instead, gently tug a plant to help loosen it from the container. You may also be able to squeeze the bottom of flimsy plastic trays or scoop your hand under the mat of soil and roots.
Gently Separate
Once the seedlings are out of their original container, it’s time to separate them. Depending on the density and size, the roots may be separate and easily distinguishable, or they may be growing together. Either circumstance is fine, but they require different care.
If the roots are small and don’t seem to be tightly woven together, start by grabbing one seedling’s cotyledon. Gently tug until the plant begins to separate from the others. I find that a pencil or similar object is useful for gently piecing apart the baby roots.
Seedlings that are more than a few weeks old are more likely to have developed large root systems that are woven together. Separating these roots is a bit more challenging but possible. You can follow the same steps outlined above. Don’t worry if a few roots break during the process—the roots may experience a slight setback, but they’ll continue to grow.
If the roots resemble a continuous mat of fibers rather than the bottoms of individual plants, you may need to gently pull this mat of roots apart rather than separate the single root systems. While this may seem dramatic, crops like lettuce, tomatoes, and basil can tolerate this process. As long as each plant has a few roots attached, they’ll recover just fine.
Grab a piece of soil and roots around each plant, then gently pull it away from its neighbors. Aim to end up with a similar-sized root system on each seedling.
Replant in Individual Containers
After you separate them, it’s time to replant them in individual containers. Ideally, you’ll up pot them into a container where they’ll grow until it’s time to transplant.
Start by filling your containers or cell trays with potting mix. Remember to use a mix that holds water, offers excellent drainage, and provides growing crops with necessary nutrients.
Poke a small hole in each container to accommodate the roots. Most seedlings should be planted so their junction of the stem and roots is right at the soil surface. However, you can plant the stems of tomatoes, eggplant, basil, and peppers under the soil. Roots will form along the underground portion of the stem, leading to a stronger plant.
After placing the seedling in the hole, gently pack the soil around the roots. Repeat this process with each seedling, then water them well.
Provide Follow-Up Care
Moving plants from one location to another is always a stressful process. When you add in separating the roots, it’s not surprising that the plants aren’t always happy after you separate them. However, fixing overcrowded seedlings is still better than leaving them as is.
Providing the ideal growing environment will help them recover. Water the soil well, but don’t keep it soaking wet. Place the trays in full sun and limit the amount of wind they experience for the first few days after separating.
They may appear wilted for a day or two, but should eventually return to a healthy state. Continue to provide the proper amount of water and light until it’s time to transplant the seedlings outdoors.
