5 Signs It’s Time to Repot Your Seedlings
Seedlings mature quickly, evolving from tiny seeds to mature plants in weeks! It’s best to repot them before they grow rootbound so they continue sprouting healthy root systems. Watch for these five signs that signal your plants need a repot—wait too long and they may suffer!
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Late winter and early spring are ideal times for starting seeds, though you can do so year-round! Some crops, like cauliflower and cabbage, perform better during fall than spring, meaning you’ll start them from seeds in midsummer.
No matter when you start seeds, the sprouted species eventually outgrow their containers. Their roots poke out the drainage holes, they lose leaves, and water drains freely from their containers. Grant them bigger containers and they’ll thrive until you’re ready to transplant them into the garden.
If seeds need large containers, why not start them in big pots from the start? Roots grow downward before spreading horizontally. A small pot encourages ample horizontal root growth, creating strong specimens that transplant well. Watch them closely and they’ll tell you what they need by the way they grow.
5 Signs It’s Time to Repot Seedlings
These five telling signs show that it’s time to repot your seedlings. They typically appear a few weeks after seed germination, when the plants’ roots are actively growing in the pots. Get them into larger containers before they form bound roots; they’ll grow well without setbacks for the rest of the year.
Water Drains Quickly
Water draining freely from the drainage holes is a telltale sign that the seedlings should be repotted. As they grow ample roots, they take up space in the container and spread into tiny air pockets in the soil. These pockets, or micropores, hold water and nutrients for them to access.
As the roots fill out the micropores, they leave no space for water and nutrients to sit. The moisture and fertilizers flow freely from the container, causing dry roots and weak specimens.
You may combat free-draining water by adding excess moisture until the pot soaks it up, though it’s best to repot the plant species so they thrive with average moisture levels. Grant them slightly larger containers that are deeper and wider than the previous ones.
Perpetually Dry Soil
When roots take up space in dirt, they lessen the water-holding capacity of the soil. Have you noticed that fresh seeds stay wet for a while, while full-grown potted plants need frequent watering? This is because of the high proportion of roots to dirt inside the containers.
Free-draining water and perpetually dry soil go hand in hand; because water doesn’t sit in the soil, it runs out the holes and leaves the plants as dry as bones. You may combat this with repeated watering, though it’s time-consuming and can lead to root rot.
It’s best to transplant your seedlings into larger pots if their dirt stays dry after watering. If left too long, the roots can grow more bound and constrict the plants’ growth, killing them before you can repot them. Your specimens should need water every three to four days, not every day!
Roots Poke Out Drainage Holes
Root pieces growing out of the pots’ drainage holes are the most common signs that seedlings need repotting. As they mature, they put down ample horizontal and vertical root fragments. They creep into every space below the soil.
Once the roots fill the pot, they’ll start adventuring outward for more soil. More root growth equals more top growth; providing plenty of underground space during the growth process leads to healthy, robust plants in spring and summer.
Catch escaping root fragments early and you’ll avoid heartache later during transplanting. As they creep out of the drainage holes they continue growing, creating a bottleneck effect you must break during repotting. This can harm the plant, as it must compensate for its loss by growing more roots rather than leaves, stems, or flowers.
Stunted Growth
Alongside the previous three symptoms, stunted growth is another sign repotting is necessary. It usually occurs after the other symptoms, as the plants struggle to continue growing in their tiny containers. Without ample water, nutrients, and space, they can’t form healthy new growth.
Stunted plants have small leaves, short stems, and little fresh growth. They also may experience frequent leaf drop, dying stems, and rotting rootballs. As with the other problems, the simple solution is to repot the plants into larger containers.
Mature Seedlings
Though these four signs are negative symptoms, you don’t have to wait until the seedlings suffer to take the time and repot them! Mature seedlings are ready for repotting when they have ample leaves, stems, and new shoots. Catch them before they grow rootbound and you’ll avoid the other adverse sprouting issues.
Peppers, tomatoes, and eggplants are ready for larger pots after they sprout four or more true leaves. If you pull on a plant and the entire rootball comes out, it’s ready for repotting. Though you can wait longer, you’ll start seeing stunted growth and perpetually dry soil as the roots continue growing in the small pot.
Your plants this year may not show any of the previous four symptoms unless you let them go too long. Most growers catch their seedlings in time, granting them larger pots as they need them. Pay attention to your plants, and they’ll tell you what they need with the signs they display.
How to Repot Seedlings
Repotting seedlings is easy enough with the right tools! Gather pots, trays, soil, and a watering can. Some species, like peppers and tomatoes, benefit from plant grow lights in dark indoor spaces. Ensure your growing crops have ample light, water, and space, and they’ll thrive throughout the seasons.
Prepare New Containers
Your new pots should be slightly larger than the existing ones—they shouldn’t be more than double the size, and they shouldn’t be so small that it’s hard to repot the seedlings. You want them to have enough space for healthy horizontal and vertical root growth.
Add soil into them so it sits on the bottom and sides. This soil cushion is where new root growth occurs. Use a potting or seedling soil mix for best results; they have fine pieces of grit that are easier to grow in than large chunks.
Situate the pots on a tray so they don’t spill in your home. The trays collect water after you irrigate, allowing you to water your plants without moving them outside.
Transplant
With pots ready, it’s time to remove the plant species from their containers. Gently lift, taking care not to damage the stems in the process. If a plant struggles to come out, orient it on its side so you can gently ease it out of the container. After removing the pot, tease the rootball a bit so it dangles downwards, and remove any circling or bound roots.
Transplant by gently dropping the rootballs into the new containers. Ensure they sit completely inside and upright, with no root fragments poking out of the soil surface. Add more potting soil around the bases to firm them until it reaches the container’s surface.
Water well, then place the plant species in bright locations where they can continue to grow. They’ll thrive for a few weeks or months before they require another repotting.
Continuously Monitor
After transplanting, continuous monitoring ensures you catch growing issues before they spread out of control. Watch for root fragments poking out of the holes in the containers, dry soil, and free-draining water. These symptoms are evidence that it’s time to repot!
Most species require one repotting before they’re ready for transplanting outdoors. Others, like peppers, may need two or three depending on how quickly they grow. Time seed starting so it coincides with your frost dates; that way, you’ll avoid overgrown seedlings and excessive repotting.
