Recognizing a Root Bound (Pot Bound) Plant

Jun 24, 2009Updated 8 months ago

A root bound plant
A plant becomes root bound if it is allowed to grow in the same pot for numerous years. In nature, a plant’s root system naturally extends three times the length that it does into the sky. As plants grow fresh foliage above soil they are simultaneously extending and thickening their root systems. If left to grow in the same space for an extended amount of time, a plant will literally suffocate itself like a boa constrictor.

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.
There are three general rules pertaining to container gardens and re-potting that one should remember at all times:

  1. All houseplants should be repotted once every two or three years.
  2. 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.
  3. Do not be afraid to remove up to 1/3 the root system when repotting.
The strength required to remove a root bound plant from its pot will be incredible. Therefore, one should try to saturate the soil before removing the plant from its pot. The water will act as a lubricant against the sides of the pot; simultaneously loosening its soil.

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:

  1. Remove all rotten and severely discolored roots/cut thickest roots in half.
  2. Do not remove any bright white roots, they’re healthy.
  3. Break up the remaining root mass with your knife and hands to promote growth.
It is also important to note that one must remove at least 1/3 of the plant's roots because they are unnecessary. The old and gangly roots that are torn from the plant will be rapidly replaced by a more functional and healthy root system.

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.