Maximizing Root Growth in Containers -1

I have written posts about How to Water properly,  soil and water availability, and about growing in small spaces.  The problem is even good growers cannot keep potting up to bigger and bigger pots to allow for bigger root masses. If you want to maximize root growth which can maximize yield and prevent disease there are some techniques you could try. A lot of container space often goes unused, because roots usually do not grow into the top few inches of soil/container. Roots generally grow towards gravity but the soil at the top of containers is often dried out from powerful lights and low humidity. Although I should mention the #1 problem I reply to is over watering. You want to find the Goldilocks of soil moisture, not too wet, not too dry.

If your pot is over one foot tall and like most growers you don’t have roots growing in the top 1-1/4inches, you are wasting 10% or more of your soil. I would wager many people waste up to 25% of the space in their pots. You should always use tall skinny pots if possible. If you use pots that are wider at the top than the bottom, the amount of wasted soil is even greater!

I have written about compost, one suggestion would be to use compost as a mulch to keep the top of the container/soil moist; the added benefit is it would also supply organic nutrients and beneficial bacteria to your plants. The down side is compost from outside could have pests, and it could attract or be food some pests too. You could try using a layer of coco coir as a mulch layer. One benefit is that because it is fibrous, water will pass right through it. This means you can fill your pot to the very top without worrying about water spilling over the sides. The coir will dry out much faster than soil, you can notice this with a color change, coir will change from dark brown (wet) to light brown (dry). If you are mindful of the soil under the coir you can keep your soil moist as the coir shields the soil from the lights, and slows soil water evaporation. Allow the coir to stay dry for a day or three. (You can use the finger test - stick your finger through the coir and into the soil to see if the soil is wet – to determine if you should let the coir dry out one or three days). A soil meter is also a tool that could help. You want the top layer of the soil to be damp, not soaked.

You could try this with other materials like perlite or vermiculite, but be careful not to use anything heavy that might compact your soil the way putting pebbles would.

Good Growing
Dr. E.R. Myers