Composting for Your Cannabis Plants

What is Composting?

Composting is nature’s way of recycling. It is the process of breaking food and plant waste down into usable soil. Microorganisms break down organic matter in the pile into available nutrients, ready for plants to absorb. This process can take weeks to months depending on what you compost. The end result is a nutrient dense soil that you can use in your gardens, indoor and outdoor. It’s an economical choice for gardening because you turn food scraps and plant waste into something usable. Every plant, including your cannabis plants can benefit from adding compost to their soil mix.

Do I Need a Compost Bin or Container?

No, you can have a true compost pile without a container in your yard or compost in a container. Although,having a pile with no container makes it more prone to attracting insects and animals. You can purchase compost bins of many different styles or make one yourself. You can make them with wood pallets, wire or plastic storage totes. The bin should have some air holes or venting for proper air flow. Be sure to put mesh on any larger holes or openings to prevent flies from laying their maggots in your compost pile. You also need to be able to access the compost to turn it regularly.

What Goes Into the Compost?

When composting, you have to have a proper balance between “greens” and “browns”. The “greens” are rich in nitrogen, while the “browns” are rich in carbon. You want to start the pile with a base of “browns”, then add some “greens” on top of that and finally add some soil to introduce the microbial life to the pile. After all the ingredients are together, you’ll need to turn over the pile with a pitchfork or shovel. You want to moisten the pile completely but not soggy.


  • Dried leaves
  • Twigs or branches; chopped
  • Hay or straw
  • Newspaper; shredded
  • Cardboard; shredded
  • Brown paper bags; shredded
  • Egg shells; crushed
  • Wood ash


  • Grass clippings
  • Weeds (if they haven’t gone to seed)
  • Fresh leaves
  • Hedge clippings
  • Flowers
  • Fruit scraps
  • Vegetable scraps
  • Table scraps
  • Coffee grounds/filters
  • Tea; bagged and loose leaf
  • Seaweed & kelp

There is so much more you can compost but decided to only list some common ones as examples. Some items will take longer to break down. For example, corn cobs and tree branches take a long time to fully decompose and break down.

What NOT to Put in the Compost

  • Meat including fish
  • Fats, lard and oils
  • Bones
  • Dairy products
  • Eggs (shells are okay)
  • Diseased or infected plants
  • Pet waste or litter
  • Glossy printed paper
  • Plants treated with pesticide or herbicide

How Long Until the Compost is Ready?

You should turn the pile over 1-3 times a week and make sure it’s moist for best results. Keeping it moist rather than wet will also help keep odour levels down. When you turn the pile, you want to introduce as much oxygen to the pile as you can. This will help to further the breakdown the materials in the pile. If you turn the pile often and keep it moist, you can have a usable compost in just 6 weeks.

The compost will be ready faster if you cut and chop everything into smaller pieces before adding it to the pile. You’ll notice the pile will create heat. This is a sign that the bacteria, fungi and other organisms are breaking down the organic material. You can check for the heat with a compost thermometer or if you just want to make sure it’s working, you can simply feel the heat with your hand.