Follow tips when transplanting indoor plants

As outdoor plants break dormancy and start to grow in response to the longer days and warmer spring temperatures, houseplants usually put on a spurt of growth as well. Eventually, these indoor plants outgrow their containers and need to be repotted. To check if your plants are becoming root-bound and need a larger pot, inspect the root system by sliding the plant out of its pot.

Most houseplants should be repotted in the spring as new growth comes out. For many people, however, that would mean repotting when the weather is still too cold outside, so the chore often doesn’t get done until the plants can be moved outside.

During the replanting process, don’t break off too many roots on a plant that is now going to get more sun and more heat. Be careful to watch the watering needs of the plant after it has been moved outside. Give them some slowrelease fertilizer while they are actively growing as well. Use the hose to give them a bath occasionally so that dust and bugs can be rinsed off. If you have plant saucers under the pots, don’t let them remain filled with water, especially during rainy spells.

Water is crucial

Watering several hours before you plan to repot a plant makes it easier to remove plants from clay pots. On pots that are 8 inches in diameter or less, place one hand over the top of the pot with the stem of the plant passing between two fingers and then turn the plant upside down. If necessary, rap the edge of the pot against a table. The root ball should come away from the pot. On pots that are more than 8 inches in diameter, if a bit more encouragement is needed, place the pot on its side and rap the top edge of the pot with a rubber mallet. Turn the plant a few degrees and then repeat the procedure until the root ball releases.

Once the plant is free, take a look at the root ball. If the soil is covered by roots, the plant needs to be moved to a larger pot. Loosen the roots, and spread them out. You can prune any roots that circle around the pot.

Pot size

If the original pot is less than 10 inches across, move it up an inch in diameter. If it is 10 inches or larger, increase the size of the new pot by 2 inches. If the pot has drainage holes in the bottom, cover them with a piece of cloth, paper or coffee filter so the potting mix is not washed out during watering. If the new soil doesn’t have fertilizer, you can add some slow-release fertilizer following package directions.

The top of the soil should sit at the same level it was in the old pot. Add potting mix to the pot, but make sure there is still room for water at the top of the pot. The soil mix will need to be firmed slightly before the plant is placed on top of it so it doesn’t settle. After the plant is placed, fill in around the original root ball with potting soil. Firm this soil with a slender stick, or tap the bottom of the pot on the table. If this firming is not done, new soil may be so loose that water will move through it rather than through the old soil.

Water the plant thoroughly after repotting, but be especially careful not to overwater for about two weeks. The new soil may stay too wet until roots start to penetrate the new soil. Overwatering can lead to the roots rotting. Some plants need to be repotted annually, though larger plants may be able to go several years before repotting.

Environmental conditions

Before buying a plant, it is important to take a look at the environmental conditions in your house. The condition that confuses people most is how much light to give a houseplant. There are many ways to measure light, but there are no light measurement tools like we do for temperature and humidity.

Let’s keep it simple. In low light, you will just barely see a shadow of your hand. If you can see a shadow with fingers, it is medium light, and if the shadow is sharp and contrasts with the light, it is a bright light.

What kind of light can you expect indoors? If there are no outside obstructions like trees or nearby buildings on a typically sized residential window, a south-facing window will have direct sun all day long. On the opposite side of the house, the north-facing window will see no direct light at all. The east side windows will get morning light, and the western windows will get afternoon direct sunlight. Within 3 feet of a directly sunlit window, there will be bright light. Then there will be medium light for another 3 feet and finally low light to about 10 feet away from the window.

Of course, shade from trees and buildings can block a lot of sunlight, making an otherwise bright window into a low-light window. Large, atrium-style windows can allow much more light into a room than a normal window.

Plants can even shade themselves. A plant that is leaning to the light or is one-sided is indicating that it needs more light. That plant needs to be rotated on a regular basis so that it gets enough light on all sides.

Many people don’t realize that tropical plants are affected by daily and seasonal temperature changes. The flowering and fruiting seasons may be signaled by temperature changes and changes in rainfall. Many houses are controlled by thermostats that keep the temperature the same 24 hours a day. It is beneficial to plants to allow the nighttime temperatures to drop — and it may benefit your utility bills.

Many new gardeners want to water their plants on a schedule. Plants in nature are not on a schedule. They may get daily rain in the wet season and then no rain for weeks during the dry season. Plants can be divided by their soil moisture needs. They may need wet, damp or dry soil, which may change seasonally. Touch the soil at the top of the pot. If it is cool to the touch, it is damp and probably doesn’t need to be watered yet.

The proper humidity for growing tropical plants is important for plant health, but it is often neglected. A tropical jungle plant may need humidity levels over 70% to thrive. The humidity level in a home in the summertime may be 40% to 50%, but in the winter, it may drop to below 20%. Plants needing more humidity will often have leaf tips that turn brown, leaf edges that turn yellow and leaves and flower buds that fall off.

You may not need to raise the humidity in the whole house to benefit a few plants. A room humidifier may be useful. They may be helped with a regular misting or by placing a tray of water under the plant. The water will evaporate and raise the humidity in the area around the plant. Too much water in the saucer under the plant may drown the plant roots. Placing some stones in the saucer to raise the plant pot will keep the roots healthy and allow the water in the saucer to increase the humidity.