Mulch is essential for a number of reasons. First, it cools the soil and cuts down on water loss. It also acts as a proactive cover that reduces erosion and suppresses weed growth. Applying cannabis mulch is easy; and it keeps the surface from drying out. Adding a 3 to 6 inch layer of mulch will also prevent sediment run-off and keep your plants happy.

Choosing the Right Cannabis Mulch

As organic mulches break down, soil fertility improves as it decomposes. The perfect mulch is one that is readily available, cheap and abundant. In other words, don’t go out of your way when selecting ground cover. Mulches do not have to be expensive. In fact, they should be the cheapest amendment in your garden and often times are free! Wood chips, straw, newspaper, cardboard, compost, grass clippings, and leaves all provide suitable options.

Mulch can also make it difficult for water to penetrate soil evenly. In fact, many mulches absorb water that often times prevent water from entering the soil. Make sure water penetrates soil evenly by using a aerated nozzle when applying water. Some mulches like rocks and stones provide great drainage, but are difficult to remove when adding new organic nutrients.

Why is Cannabis Mulch so Important?

Applying mulch is a common practice that most cannabis growers employ. The best time to apply mulch is when temperatures rise and top soil has warmed. To check your soil temperature, inexpensive soil thermometers work great. On hot days, it is easy for top soil to rise above 120°F. Cannabis will not grow under these conditions. Regardless of how you grow, you should apply mulch in all growing conditions including pots and raised beds. Small pots can be difficult for controlling soil temperatures and heat stress, especially black pots exposed to direct sun light.

Indoor growers should avoid outdoor mulches that might have bugs. For indoor growers, I usually recommend using expanded clay pellets or perlite. Not only will they insulate your soil, but they will also protect your plants from fungus gnats!

Plastic Mulch for Cannabis

I’ve noticed recently that some growers are using plastic mulch or rubber mulch to keep their soil cool. Rubber mulch is cheap and easy to find. It also doesn’t really degrade so it lasts a long time. And since it doesn’t have any water retention ability, it therefore allows water and nutrients to pass freely. Another positive is that it doesn’t attract insects. However, I personally can’t get on board with recommending this type mulch. For me, it doesn’t seem right to put an inorganic mulch that is petroleum based on top of the soil of my flowers. I get that the manufactures state that it is safe for flowers and plants, but is it really worth the risk of toxic substances leaching into your soil? Nah.

Cover Crops for Cannabis

Some growers use cover crops to nurture their soil. In my opinion, cover crops should be employed during the offseason to maintain your soil. Cover crops have a number of benefits. For example, cover crops prevents erosion, eliminates unwanted weed growth, sequesters nutrients, reduces soil compaction and provides a suitable habitat for your beneficial organisms. There are a lot of different cover crops that are suitable for your grow. My favorite type is clovers because they sequester nitrogen back into your soil!