Homemade Compost for Weed: How Long It Takes and How to Apply It

Homemade compost for cannabis

Compost is organic matter broken down by microorganisms that release nutrients into the soil as they feed, and homemade compost usually takes a few months to a year to mature. Once it's ready, you can top-dress your cannabis plants with it, mix it into your soil before planting or brew it into compost tea, and your plants use those nutrients to grow.

The basic recipe for traditional compost is a mix of nitrogen-rich 'greens' and carbon-rich 'browns,' plus oxygen (air) and moisture (water).

The microbes doing the work are aerobic bacteria, which need oxygen to survive, so good airflow is key. They also need water to thrive (ideal moisture is somewhere between 40% and 60%). As they break things down, the bacteria give off heat (and carbon dioxide), which warms up the pile. If your compost feels warm to the touch, that's a good sign it's working.

Composting is also a natural way to recycle food scraps and other organic waste so they can return to the soil, which cuts down on trash and is good for the planet. It also helps you rely less on pesticides and synthetic fertilizers, which is a real win for the health of animals, plants and people alike.

Making compost at home

Making your own compost is the best way to guarantee a steady supply of high-quality nutrients. Composting works best in warm, sunny weather, since the breakdown of organic matter slows way down when temperatures drop and the cold sets in.

How do you make good compost at home?

Step one is finding a good spot: somewhere warm and away from the busiest parts of the house. Composting means organic matter is rotting, so it can produce some smells (although a well-managed pile really shouldn't stink). Keep it somewhere easy to reach with a hose nearby, since you may need to add water on hot days.

You'll need a compost bin or container, which can be as basic as a homemade wooden box. Lots of people just use a big plastic tub. Drill holes in the bottom and sides to help with airflow. A lid matters, because it helps the compost hold on to heat and moisture.

You'll also need garden tools to turn the pile so the material on top gets mixed in with the rest. The warmest part of the pile is the center, so turning it often helps everything break down evenly.

How long does homemade compost take?

How long your compost takes depends on several things: temperature, moisture, the materials you use and your composting technique.

In general, it can take anywhere from a few months to a year to get fully mature, ready-to-use compost. During that time, microorganisms break down the organic material through natural decomposition.

To speed things up, keep a good balance of carbon-rich materials (dry leaves, twigs, paper) and nitrogen-rich materials (kitchen scraps, grass clippings, manure). And turn or mix the pile regularly to get air in and speed up decomposition.

Homemade compost is a cheap, sustainable way to recycle organic waste into high-quality organic fertilizer. Use it in gardens, containers and vegetable beds to enrich the soil, improve its structure, help it hold moisture and feed your plants naturally.

The composting process, layer by layer

Start with a layer of dry grass and leaves. As you add more layers, aim for roughly 60% carbon materials (dry grass and leaves) to 40% nitrogen materials (green plant matter). Other good carbon sources include untreated cardboard, straw, wood chips or sawdust, dry twigs and so on.

On top of that first carbon layer, add nitrogen-rich material like cow or horse manure, grass or garden clippings, eggshells or veggie scraps (carrots, cucumbers, pears, apples, potatoes and so on, chopped up fine). 

The third layer should be soil that's free of pesticides and synthetic fertilizers. Check on your compost regularly and mix it well every few days, adding water whenever the center starts drying out. 

Leave out: dairy, fats, meat, fish and dog or cat poop. Some of these won't break down or take forever, and others will attract animals or pests you don't want. When it's done, your compost should be dark and earthy.

Why compost is great for cannabis

Compost feeds the soil, while fertilizers feed the plant. Compost also builds richer, more balanced soil. Use both together and you'll give your cannabis plants ideal growing conditions.

Homemade compost is dead simple to use. Spread it as a layer of topsoil around your plants. How much you need depends on the quality of your growing medium and its nutrient levels. Mixing compost into your soil is also a great way to kick off an indoor grow.

How do you apply compost to cannabis plants?

One common way is top-dressing: spreading a layer of mature compost over the soil around your plants. That layer works like a protective mulch, helping the soil hold moisture, keeping weeds down and feeding the roots as it slowly breaks down. To do it, spread a layer about 2-5 cm (1-2 in) thick around your plants, keeping it off the stems to avoid rot.

Another option is mixing compost into the soil before planting or transplanting. Dig a hole big enough for the root ball and backfill it with a mix of soil and compost. That loads the soil with nutrients and organic matter and gives your plants a great environment to grow in.

You can also make compost tea: soak some compost in water for a while, then use the liquid as a natural liquid fertilizer. Spray it on the leaves or pour it at the roots for a fast, effective nutrient boost.