Indoor plants respond to the longer daylight hours by moving from a dormant state to producing new growth. Now is a good time to assess plants and determine if they need to be repotted. Repotting always involves disturbing the roots. An actively growing plant will regenerate new roots quickly and suffer little setback as opposed to a dormant one.
A typical indoor or tropical plant will do better underpotted as opposed to being placed in a large pot. Potted plants tend to fill the pot first and put on new growth once they have developed their roots. If the top of the plant is not large enough to produce nutrients to develop a large root base, the whole plant suffers. Another scenario is that the excess soil will hold too much moisture and the roots will begin to rot.
There are a number of indicators to show that a plant needs repotted.
Plants should be watered once a week. Give the plant enough moisture that the excess flows out of the bottom of the pot. When the pot is filled with roots the soil doesn’t have space to hold enough moisture making it necessary to water it more often.
If there are too many roots in a pot the roots and soil can push upward leaving little or no space between the lip of the pot and the soil. In this case watering is difficult as the water is just as likely to run over the top of the pot as sink into the soil.
Look for roots that are growing out of the drainage holes on the bottom of the pot. This happens more often if the saucer under the plant is moist.
If any of the above symptoms are present, remove the pot and look at the roots. If the plant needs to be repotted, the rootball will look like a mass of roots making it difficult to see the soil. Expect to see larger roots that circle the pot. At this point the plant needs to be repotted into a pot one size larger than the present pot.
The next size up gives the plant some room to grow but roots will quickly reach the edge of the pot and start producing new growth.
When repotting a plant, use a clean container with good drainage holes. Place moist soil on the bottom of the pot. Break up or disturb the existing roots to encourage them to move out in the new soil before placing it in the pot. Place the plant in the center of the pot and place new soil between the root ball and the inner wall of the pot. Press the new soil and existing plant firmly into the pot. Water the soil to remove air pockets and add soil where needed. If possible, place the plant in an area that doesn’t receive direct sunlight for a few days allowing the plant time to adjust to the transition.
When plants appear to be unhealthy first check the foliage to see if there are hosting insects. If this is negative, remove the pot and look at the roots. If a massive pile of soil spills out and very little root mass, chances are that it will need a smaller pot. Placing a plant in a smaller plant will encourage new growth.
Check the moisture of the soil both at the top and bottom of the pot. If a plant has been over watered, the top of the soil may be dry but the bottom will be wet. When this is the case look at the roots. Roots that are alive and healthy, will be firm and pliable. Dead roots are most often black, limp, flat and come apart easily.
Remove all the unhealthy portions of the roots and pot the container up in a smaller pot. One where the roots can touch the sides.
It will take plants a couple of weeks to recover from being repotted, but once adjusted the plants flourish.
Linda Tomlinson is a horticulturalist that lives by Rocky Mountain House. She can be reached at firstname.lastname@example.org