by Sunny Datko
Air pruning is a technique designed to encourage the plant to grow a denser system of root hairs, increasing nutrient absorption and enabling the plant to grow more rapidly.
Air pruning works by exposing the root tips to relatively dry air, causing the apical cells at the very tip of the root to dehydrate, or become air-pruned. This stimulates the growth of secondary roots that branch out from them within the growing media. These secondary roots spread throughout the container until they reach the sides and bottom where they get air pruned again, stimulating more root growth. The overall effect of this technique is the establishment of a well-developed root system that is spread evenly throughout the entire pot.
In plastic pots where air root pruning does not take place, the roots tend to keep on growing and spiraling in the pot, discouraging root expansion. When the plant is transplanted, the roots will continue to circle inside the new container, reducing uptake of water and nutrients and limiting growth. Plastic pots can also get fairly warm, especially under grow lights or if exposed to direct sunlight. Healthy, highly branched root structures allow a plant to take in more water and nutrients, accelerating growth and increasing overall plant health. Much like pinching out the top of the plant to create a bushier plant, air pruning allows the root tip to dry in order to create a more branched root system within the growing media.
Spotlight on Smart Pot:
These soft growing containers allow more air to reach the growing medium and roots, improving drainage and keeping the root system from overheating on hot days. Plant roots also benefit from their natural tendency to grow into soft surfaces like the Smart Pot, becoming thick and healthy instead of circling the inside of the pot and becoming root-bound. These pots are aeration containers allowing the air to prune the plant root structure. Simply remove the containers before transplanting. These pots will help plants become established more quickly after transplanting.