Unlike leaves and flowers, roots grow underneath the soil where we can’t see them. They search for fertile ground, creeping and crawling into pockets underground. After filling a container with roots, the bottom ones search elsewhere for more dirt. You’ll see plant roots sticking up above the container and below through the drainage holes. 

The roots will continue growing outside the pot if you leave them alone. This creates a tricky situation when you’re ready to transplant—the fragments will most likely break off during the process! Rather than leaving them alone, it’s important to catch rootbound plants before they bind themselves. 

There are many reasons a plant grows rootbound, and there are also many solutions to help. Which is best for you and your plants depends on your growing situation. Let’s first discover why plant roots may stick out from a pot before learning how to fix them.

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Why Do Plant Roots Stick Out of Pots?

Rootbinding is common in houseplants but can be fixed with simple solutions.

Roots typically stick out because of rootbinding. There are many reasons why plants become rootbound. It’s common in spring when gardeners sow seeds early, and in houseplants that sit in their pots for many years. No matter the reason, there are simple fixes to get your plants growing well again. 

Deep Seeking Roots

Some species have deep taproots, fibrous roots, or creeping stems that determine their growth patterns.

Different species grow differently. Some sprout long and deep taproots, some form fibrous root systems, and others have creeping stems that root freely. Taproots often poke out of containers because their natural inclination is to grow downwards rather than outwards. Some common taproot-forming species are avocados, carrots, and mullein.

Though fibrous root systems tend to stay near the soil’s surface, they can also creep from pots’ drainage holes. Keep a close eye on your specimens to determine if they need more space. Common signs of a rootbound plant include leaf drop, slow growth, and water running freely from its pot. 

Spreading species like horsetail, mint, and bee balm may form new colonies if they escape. Their free-rooting stems can grow out of the pot’s holes and sprout new clones away from the mother plant. Catch these early before they spread into garden soil to prevent them from taking over your garden.

Shallow Containers

Small, shallow containers cause rootbinding faster than deeper, wider ones, so size matters.

In addition to the type of root system, the size of the container influences how quickly houseplants become rootbound. Shallow, small pots lead to root fragments sticking out more quickly than deep, wide planters. Give a plant a container two to three inches deeper and wider than its rootball.

Some species thrive for a long time in shallow containers! Houseplants like succulents, cacti, and ferns often have shallow rootballs, and crops like lettuce, spinach, and arugula are similarly small-rooted. 

Though you can transplant rootbound specimens, it’s best to factor in the mature size of your plants before choosing their pots. That way, you can select a suitable container that matches your plant. If it’s too big it may lead to root rot, and if it’s too shallow you’ll see root fragments poke out quickly after planting. 

Mature Specimens

Spider plants often outgrow their space, so frequently check drainage holes for root tips sticking out.

Houseplants live for many months or years in the same pots! They’re slow-growing and require less repotting than annuals, vegetables, and fruit trees. Though they’re slow-growing, they’ll outgrow their containers eventually. 

A root tip or two poking out of the drainage holes is a big sign your houseplant needs some care. Indoor species like coleus, pelargonium, and spider plants often outgrow their vessels. Keep a close eye on them and frequently lift their pots to see if root tips poke out.

Bonsai

Bonsai trees stay small through pruning, trimming, and repotting, best done in early spring.

Bonsai is a Japanese form of tree care. It creates miniature versions of trees that resemble their adult forms. I love making bonsai material—it’s an awesome hobby to start if you like growing trees but lack the space for large specimens. 

In bonsai, trees are kept small through root pruning, repotting, and trimming. Frequent care is necessary to keep them both small and healthy. The best time to repot them is early spring before the buds open up. 

With bonsai, creeping root tips are perfectly normal. Trim them off and wait until early spring for repotting. 

What to Do

Now that we know why plants outgrow containers, let’s explore four simple ways to fix it.

Now that we know why plant roots stick out of their pots, we’ll discover four easy ways to help them. The best solution depends on the species and time of year. Let’s dig in!

Trim Off Roots

Trim roots that are sticking out to keep plants contained in their pots.

The first solution is the easiest—simply trim the overgrown tips and leave your plant in place. This is best for species with deep-searching roots, as you’ll encourage them to spread out in the pot instead of growing outwards. 

Trimming is also beneficial for bonsai plants from summer through winter. It keeps the roots growing inside the container rather than onto drainage trays or tables. 

Though trimming removes the issue, the fragments will likely grow back in a few weeks. This is a temporary solution; eventually, you’ll want to repot, uppot, or transplant the specimen. 

Root Prune and Repot

Root pruning is best for mature specimens, starting in early spring or fall for healthy growth.

Repotting is best for bonsai, houseplants, and potted specimens on patios or porches. Rather than giving the plant a new container, you’ll trim its roots and plant it in the current one with fresh soil. This keeps ornamental species small so they don’t outgrow their space.

Root pruning can damage sensitive specimens, so it’s best for mature ones that can handle the transition. Start in early spring in cold climates, and in fall or spring in warm ones. Remove the perennial from the pot, loosen its rootball, and trim the bottom layer. 

Dump the old soil out of the pot, then fill it with fresh potting soil, compost, or a homemade dirt blend. Your houseplant, bonsai tree, or potted specimen should fare well for a year or two before it needs repotting again. 

Up-Pot

Loosen and trim roots before placing them in a larger container with fresh soil and water.

Up-potting is similar to repotting, except you’ll trim less of the rootball and put it in a new container with fresh dirt. This method is best for quick-growing species, old houseplants, and rootbound specimens. 

Remove the plant from its container, loosen the roots, and trim their ends. Then, place it in a larger pot with new soil or compost. Water it well, then put it back in its spot. Avoid moving it to a new area, as it’ll need to adapt to its new home before it’s hardy again. 

Transplant

Fast-growing seedlings like vegetables and herbs need timely transplanting to avoid rootbound stress.

Transplanting is the easy fix for rapidly growing seedlings. Veggies, herbs, and flowers need uppotting or transplanting soon after germination. They’ll struggle if they sit in their containers with circling roots. 

For crops like peppers, tomatoes, and tomatillos, start their seeds in 5” cube pots instead of cell trays. That way, they’ll have more time to fill their pots before they need uppotting or transplanting. Harden off the seedlings a week or two before you plant to transplant them. 

To transplant, prepare a hole in raised beds or in-ground beds. Dig as deep and twice as wide as the rootball, and put the plant inside the hole. Trim the rootball during planting if it looks rootbound. Backfill the soil until it reaches ground level, then water your specimen well. It’ll adapt to the site and produce bushels of leaves, flowers, and fruits!