There is not a distinctive period of time in which one can conclusively determine that a plant will become root bound. Depending on the plant’s species and size of its container, it may take over fifteen years before symptoms of severely constrained roots appear. A root bound plant will eventually suffocate itself regardless of how often one may water or fertilize. Unexplainable foliage decay is typically the first noticeable sign of this condition It is important to diagnose a root bound plant right away and take appropriate action to preserve the life and vitality of the plant.
Other indicators of a root bound plant include:
- Roots visible from drainage holes or in masses above soil.
- Poor water retention; the water is not properly absorbed.
- impenetrable top soil.
- All houseplants should be repotted once every two or three years.
- It is wise to purchase a pot that is no larger than double the size that you’re currently using. This will allow your plant to reach its full potential and stay healthy.
- Do not be afraid to remove up to 1/3 the root system when repotting.
When it finally emerges, the roots will most likely appear thick, rotted/discolored, and wrapped around in desperate spirals; molded to the shape of its old container. The soil entangled between the deepest roots will be severely compacted and as dry as if it hadn’t been watered in three weeks. These observations are typical of severely root bound plants and must be corrected before re-potting.
There are three steps:
- Remove all rotten and severely discolored roots/cut thickest roots in half.
- Do not remove any bright white roots, they’re healthy.
- Break up the remaining root mass with your knife and hands to promote growth.
Center the revived houseplant in its new pot and firmly pack soil around the edges. Do not be alarmed if the plant suffers or experiences stunted growth for awhile after it is re-potted. The foliage may temporarily weaken or seem dormant because the plant intensively focuses its energy on healthy root fortification and homeostasis.
For more information about container gardening, read a beginners guide to container gardening.