By Dr. Matthew Lisy, UConn Adjunct Faculty
UConn Home & Garden Education Center
Finally, spring is here! It will soon be time to repot all our houseplants as soon as the cold weather completely stops. Many of the plants purchased over the winter, as well as the ones sitting around for years should be repotted. This does not imply that the pot size needs to be increased. Many times, the plant can be left in the same size pot. If it is rootbound, and the plant is known to get large, it’s good to go one pot size up. Increasing the pot size when it is not needed just leads to root rot as the soil will not dry out properly. Alternatively, if the plant is getting big, another option is to divide it into numerous smaller plants, each requiring a smaller pot.
Many people think that if the pot size does not need to increase, then there is no need to repot. This could not be further from the truth. The plant is in a fixed medium. The soilless mix will quickly run out of nutrients, even with regular fertilization. Also, salts tend to build up in the soil, which harms the plant over the long run. This is a natural consequence of plants in pots. Soil can also get compacted too much over time and interfere with proper aeration of the root zone. Tease away the loose soil from the root ball being careful not to break the roots. Add the new soil and watch the plant grow!
This is also a great time to change out the pot. Most of our houseplants come in plastic pots. These are usually not very attractive. Plastic pots are good for plants that like to be kept moist. I prefer a clay pot in most cases. This allows the soil to breathe and makes it harder to over water. What I do not care for or recommend are the automatic watering pots. I have found that these have a tendency to keep the soil too moist, and do not allow for a drying out period between waterings. Stores use them as they require no maintenance from their staff, and the plants cannot wither and die due to lack of water. Long term, these types of pots lead to root rot.
Different plants have different soil needs. Cacti and succulents like it dry and fast draining. Orchids like it airy and chunky. Most houseplants prefer a mix that holds moisture but drains. Try and match the plant to the right soil type. There are great commercial mixes available for purchase, and prices on these have come down some lately. Take some time to research the proper soil type for each plant. Many of the plants take a typical houseplant mix, but some require additional drainage. In this case, add perlite and/or sand. To enable to soil to hold moisture for a longer period of time, add some vermiculite.
In all honesty, almost any soil can work for almost any plant provided that the watering is controlled. Most of the time, houseplants get overwatered which leads to fungal problems. People want to water at some magical interval, like every Friday, for example. In reality, the weather greatly influences how quickly or slowly our plants dry out. Sometimes they need water sooner, and sometimes they do not need water at all. Let the plants determine the watering schedule. If all these suggestions are followed, our plants will be living in a potted paradise, as will we!
The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations.