My next-door neighbor who owns a landscaping company thinks I have lost my mind.
I am cutting rows of big round holes in the sides and bottom of the 30 new 27-gallon growing containers that I bought this year to expand my garden with a hold saw attached to my cordless drill. He laughed and said "they will never hold any soil in them now with all those holes in them". Apparently he is absolutely clueless when it comes to air-pruning.
Air-pruning allows the plants to develop a fuller healthy root system which does not happen when growing in traditional plastic pots. When you grow in a plastic pot, once the tap roots reach the sides of the pot they continue to grow, wrapping round and round the pot causing the plant to become "root-bound". With air-pruning, this does not happen.
Just like when growing seedlings in soil blocks, in an air-pruning container, once the tap roots reach the sides of the container and are exposed to air, the root stops growing which sends a signal to the plant for it to produce the finer capillary roots which are more effective in providing water and nutrients to the plant than the larger tap roots are. The main function of the tap roots are to secure the plant into the ground for stability. The smaller capillary roots are the roots that actually feed the plant.
By air-pruning, you are forcing the plant to develop a healthier root system and preventing it from getting root-bound. This leads to a much healthier plant which will produce a more plentiful harvest with less chance of plant diseases and pest problems.
To turn any plastic container into an air-pruning grow container, simply take a drill with a hole saw and start cutting rows of holes all around the container.
Typically, I will use either a 2" or 3" hole saw (whichever I happen to have available) to cut the holes in the sides of the containers. I will use a ½" drill bit to drill many holes into the bottom of the containers for drainage.
Once you have the sides of the container filled with holes, you need a way to hold the soil inside the container for the plants to grow in. The best thing to use is simple weed fabric, but you can also use burlap or any similar fabric which will allow air and excess water to pass through it. Simply cut a piece large enough to line the inside of the container with, and start filling the container with your preferred potting soil mix.
The potting soil will hold the fabric against the sides of the container so there is no need to attach it with anything.
The air-pruning holes in the sides also allow excess water to escape the container so the roots do not become swamped in heavy rain leading to root rot.
Air-pruning growing containers can be used for any plants. You can also make smaller air-pruning containers for your house plants and flowers. They are also perfect to start trees in, or to grow dwarf fruit trees.
I will be using these containers to plant my beans, tomatoes, peppers, and potatoes and sweet potatoes so that I can expand the capacity of my garden this year.
These grow containers will last you many years, and depending on the fabric that you chose to line the inside of the containers with, the lining should last anywhere from 3 to 12 years as well. I always recommend going with the higher-quality weed fabric so that they will last longer before you have to replace the lining saving you both money and time.
Hopefully that gives you a better idea of what air-pruning is, and how easy it is to make your own D.I.Y. air-pruning growing containers instead of buying the expensive manufactured versions that are available.
Until Next Time,
Aloha & 73