Compost

Marijuana Horticulture

by Jorge Cervantes

Compost is outstanding. It solves most problems outdoors. Compost is an excellent soil amendment. It holds nutrients and moisture within its fiber. However, using backyard compost indoors is tricky.

Some growers have no trouble with organic composts, but others have bad luck and even lose their entire crop when growing in backyard compost. Good compost recipes are available from monthly publications such as Sunset, Organic Gardening, National gardening, etc, or from the companies specializing in organic composts. Outdoor growers love compost. It is inexpensive, abundant, and works wonders to increase water retention and drainage. It also increases nutrient uptake because of biological activity. Indoors, compost is not very practical to use in containers. It could also have unwanted pests. If using compost indoors, make sure it is well rotted and screened.

A good compost pile includes manure – the older the better. Manure from horse stalls or cattle feedlots is mixed with straw or sawdust bedding. Sawdust uses available nitrogen and is also acidic and not recommended. Look for the oldest, and most-rotted manure. Well-rotted manure is less prone to have viable weed seeds and pests. Fresh nitrogen=packed grass clippings are one of my favorites to use in a compost pile. Put your hand down deep into a pile of grass clippings. The temperature one or two feet down in such a pile ranges from 120 to 180F. heat generated by chemical activity kills pests, breaks down the foliage, and liberates the nutrients.

Build compost piles high, and keep turning them. Good compost pile recipes include the addition of organic trace elements, enzymes, and the primary nutrients. the organic matter used should be ground up and in the form of shredded leaves and grass. Do not use large woody branches that could take years to decompose.

Before using compost indoors, put it through 0.25 inch mesh hardware cloth (screen) to break up the humus before mixing with soil. Place a heavy duty framed screen over a large garbage can or a wheelbarrow to catch the sifted compost. Return earthworms found on the screen t the medium and kill cutworms. Make sure all composts are well rotted and have cooled before mixing with indoor soil.

Some growers mix up to 30 percent perlite into organic potting soil that contains lots of worm castings. Heavy worm castings compact soil and leave little space for air to surround roots. Adding perlite or similar amendments aerates the soil and improves drainage.