As your houseplant grows larger and the roots either begin to grow through the drainage holes or become pot bound, repotting the plant into a larger pot will become necessary. After deciding to repot, following a few steps is all that's needed to complete this task successfully. First though, have fun looking for and choosing a container that will really complement your houseplants.
Choosing a container
Many varieties of containers are available, but the container you eventually select should be based on your preference. There are, however, a few considerations to think about when choosing a container. The new container should be just slightly larger than the current one, as a container that is too large may look out of balance with the overall plant. Containers should not detract from the plant; rather the size, color, and material chosen should complement the size of the plant, leaf texture, and leaf and flower color. Before repotting, test perspective containers by placing potted plants inside them. Then place the plant in the location where you'll display it permanently, step back, and take a look at the entire combination. Ask yourself whether the color and texture of the container compliments or detracts from the plant. Is the size of the container appropriate, or is it too small or too big for the plant? If you are not pleased with the look, try another option and give the combination another critical look.
When choosing a container, the basic options are plastic and clay (terra-cotta), clay being available in glazed and unglazed. Both have advantages, and again the option you choose is primarily based on your preference. An advantage of choosing a plastic container is that it is lighter weight and easier to move than a clay pot when the plant and potting mix are added. Clay pots, on the other hand, are less likely to tip over when a plant becomes top heavy and the potting mix dries out.
Other advantages of using clay pots include reduced waterlogging and salt buildup, as the clay tends to pull water and soluble salts from the potting mix. For these same reasons, plants in clay containers will need to be watered more often than plants in plastic containers. The decorative features of these types of containers can be numerous, as more ceramic, fiberglass, and other synthetic containers are available for purchase.
Another option is to place potted houseplants in a potholder. Potholders can be made of metal, wood, or other decorative materials; however, they may not be suitable to plant a houseplant in. Instead, a potted houseplant can be slipped inside the container to achieve the desired look.
A container with drainage holes is necessary for excess water to drain, preventing the potting mix from becoming waterlogged--this can contribute to potential disease problems. Drill holes in the bottom of a container if necessary. Then use a drip tray to collect excess water and prevent furniture or surfaces that are not waterproof from becoming damaged. If it is not possible to drill a hole through a decorative container, first repot the plant into a container with a drainage hole and then use the decorative container as a potholder. Make sure that there is space between the drainage hole and the bottom of the decorative container to allow water to drain freely from the potting mix.
Deciding if the plant is pot-bound
The best time to repot a plant is in the spring so that actively growing roots will have enough time to grow into newly added potting mix. There are several signs that houseplants can exhibit when they are pot-bound. First check the frequency you are watering the houseplant.
- Do you notice that the potting mix dries out quickly even during periods of cooler temperatures?
- Also, are any roots growing through the drainage holes?
- Does it appear that the foliage and stems have either stopped growing or growth has slowed even when fertilized regularly in spring and summer?
If the answer to any of these questions is yes, remove the plant from the container and examine the roots. If the roots are circling around the rootball or are so dense that it is difficult to see any potting mix in the bottom third of the root ball, it's time to repot.
When you discover that your houseplant is pot-bound, you have a few options. First you need to decide whether you want the plant to continue to grow larger or if you're satisfied with the current size. If you don't want a larger plant, it will be necessary to remove the outer section of plant roots, return the rootball to the container with some new potting mix, and cut back some of the plant's top growth. If the goal is to let the plant grow larger, get ready to repot it.
Choosing potting mix
Using garden soil in indoor containers for houseplants could lead to disease and pest problems. Instead, choose a potting mix or potting soil especially created for potted plants. These could include a composted soil or peat mixture with fertilizers to supply nutrients. A peat-based potting mix will weigh less than a soil-based mix; however, it is more difficult to wet if it dries out. Wet the potting mix prior to repotting houseplants to ensure that the potting mix will absorb water evenly. To create your own potting mix refer to the fact sheet entitled "Homemade Potting Medium."
Repotting the plant
After you chose an appropriate container and potting mix, you can begin the repotting process. Water the plant in its original container and let it sit for one hour before repotting. If the container was used previously make sure that it is clean before you start. If you have a new plastic container, no preparation is necessary. A new clay container will require overnight soaking in water. This will prevent the container from soaking up any moisture from the potting mix when the plant is first repotted. If using a clay container with drainage holes, place a few pieces of a broken clay container over the hole. This will allow excess water to drain through the hole, but prevents potting mix from doing so. Next, remove the plant and gently "tease" the roots so that they are no longer circling the rootball or are densely matted. Place some potting mix in the container so that when the rootball is placed on top, the top of the rootball is slightly below the lip of the new pot.
Then add more potting mix around the rootball and gently firm the top layer so that the potting mix fills the container, but is not so compacted that it restricts water and air movement into and through the pot. When filling the container, leave an inch of space between the potting mix and the top of the container so that there is room for water and additional plant growth. Next, water the potting mix and place it its intended location.
- Hessayon, D.G. 2002. The Houseplant Expert. Transworld Publishers, London.
- Jantra, I. and Kruger. 2000. The Houseplant Encyclopedia. Firefly Books, New York.
- Kramer, J. 1999. Easy-care Guide to Houseplants. Creative Homeowner, Upper Saddle River, New Jersey.
Prepared by Kathleen M. Kelley, assistant professor of consumer horticulture and Mary Concklin, Montgomery County extension educator.