Lloyd Johnson - The Beginner's Guide to Growing Marijuana

Start with compost. Successful compost building must balance four ingredients: carbon, nitrogen, moisture, and oxygen. Leaves, straw, and cornstalks are high in carbon. Manures provide nitrogen. Ideally, use three parts carbon-rich materials like dead leaves, shredded newspaper, straw, or cornstalks to one part nitrogen-rich materials like fresh leaves, manures, vegetable peelings, or fresh grass clippings.

Your pile should be at least three cubic feet, if not larger. If you use a composter, inoculate the mix with soil, finished compost, or fresh manure. You want the pile to get hot and “cook” in the beginning. The heat will kill weed or grass seeds that may be in the manures. Turn the pile once a week and keep it moist. The compost is ready when it is cool and looks like moist chocolate cake. It should smell good, like fresh-turned earth.

Make your own compost from one-third horse or cow manure layered with two-thirds leaves. Sprinkle with some high-nitrogen blood meal, keep moist, and turn it weekly. The more shredded your ingredients, the faster they will become finished compost.

Compost can take nine to twelve months to mature, so outdoor cannabis gardeners should build compost piles in the fall. Some growers build a new compost pile over each plant site each fall. Then, in the spring, they mix it into their soil, test to see what amendments, if any, are needed, and the planting sites are ready and refreshed.

Every type of plant has a different perfect level of soil acidity/alkalinity that allows it to perform to optimum standard. Cannabis in general prefers soil to be just slightly acid at 6.5. This is about the same as a tomato plant. If you have a garden spot where you have successfully grown large and healthy tomatoes, it is probably going to be all right for your cannabis. Soil pH is measured on a scale from 1.0 to 14.0. A pH of 7.0 is pH neutral; pH below 7.0 is considered to be acidic; and pH higher than 7.0 is considered to be alkaline.

The pH level of your soil will determine how well your plants are able to absorb nutrients. If the pH level is out of the proper range, the growth rate of the plants will slow down or even stop. Your plants will become visibly stressed. It is worthwhile to purchase a meter or test kit; you can put your young cannabis plants into properly balanced soil from the start and avoid stressing or damaging the plants from too high or low pH levels.

If you are using purchased, bagged, premixed soils, the nitrogen, phosphorus, and potassium (N-P-K for short) levels should be listed. If you are mixing your own soil, it is advisable to test your soil for N-P-K using a soil test kit. These are easy to use, and there are reliable kits that contain separate tests for pH, nitrogen, phosphorus, and potassium.

A soil test kit will contain materials for a certain number of tests before you have to buy another; some can be used to check pH, nitrogen, phosphorus, and potassium levels ten times. Once you have tested your soil, you will probably need to make some amendments; cannabis is extremely forgiving of less than perfect soil conditions, but your goal is to raise healthy, productive plants that produce delicious, resin-covered flowers. If the plants are struggling, you will fall short of this goal.

A pH meter is long lasting and gives more accurate results than other methods of measuring pH. They have probes and batteries that eventually will need to be replaced, so consider a one-time use pH test kit. If you continue growing, and are continually buying new test kits, a meter can be a good investment.

Different organic soil amendments are usually needed when you are starting a grow site. Unlike chemical fertilizers, organics rarely burn plants, but testing your soil and understanding the different properties of different organic amendments can help you choose wisely. (It will help your budget, too.) Packaged amendments generally list the big three of plant needs as follows: nitrogen (N), phosphorus (P), and potassium (K). Always check, as extremely high nitrogen levels can burn plants.

The great value of manure is its extended availability of nitrogen, which is of particular value in readily leached sandy soils. Nutrient content and rate of availability can vary, depending mostly on manure source or type, how it’s applied, and water content. Fresh manure worked in immediately after spreading will retain the most nitrogen.

The advantages of adding organic matter content, and disadvantages of possible weed seed, should be considered in using uncomposted manure. Manures should be composted before using in direct contact with growing cannabis plants. Uncomposted manures should be applied in the fall to outdoor grow sites; they will compost and mellow through the winter while allowing winter rains to leach any salts.

Composted manure can also be used to make a tea to feed your plants during the vegetative stage; there is little chance of burning the plants, so you can be quite generous and feed a manure tea as often as once a week. Hot or fresh manure should be composted before using. Manures are usually available free from small farmers or horse stables.

Mushroom compost is not made from mushrooms but for them. Mushroom farms make this compost as a growing medium for commercial mushroom crops. Mushroom compost is normally made in a hot composting process with straw, animal manure, and gypsum. Frequently the materials come from racetracks, where racehorses are bedded on oat or wheat straw.

There are usually other nutrients added either while composting or after composting. Many of them are organic in nature, such as blood meal or cottonseed meal, but sometimes there are inorganic additives such as urea.

The one big advantage of mushroom compost is the price; large amounts are incredibly cheap, especially if you pick it up yourself. The fine texture of mushroom compost also makes it easy to dig and work with. Ideally, you will have a mushroom farm close enough to pick it up yourself; generally the farm will load your truck for you. Some farms will give the compost away, but most are now charging a nominal fee for a truckload.

However, mushroom compost does present some problems. Sterilization is one problem with mushroom compost; microbiology is vital for disease prevention and in supplying nutrients to your plants. Spent mushroom compost lacks these benefits; it is basically dead matter, though it still provides a good substrate and food source for that biology. You can reintroduce microorganisms by mixing with your own compost before applying it, or set it outside and let nature start working on it. Always check with the supplier to make certain they have not used pesticides, and smell the compost before you buy it. If it smells like chemicals, start asking questions.

Another problem is that mushroom compost tends to have a high salt content. This is not necessarily very different from any manure-based compost. Putting the compost outside for a while will allow rain to leach away the salts, or you can speed up the process by watering the pile. Due to the salt content, use mushroom compost to improve tilth in clay soils, but avoid using it too heavily year after year. Eventually you will have too much salt, which will impede the plants’ ability to take nutrients from the soil.

There is also the fact that many mushroom composts contain traces of synthetic fertilizers. This will also eliminate it as the preferred compost for yearly application on outdoor grow sites. Do not use mushroom compost as a replacement for good compost, but it is a cheap soil amendment.