Mulch and Hemp: How Mulching Contributes to Better Growth

06. 11. 2023

You have probably seen mulch in flowerbeds, vegetable gardens or under trees. But did you know that mulch can also be beneficial for cannabis plants? Mulching is needed for several reasons. It is an essential part of organic growing. It provides protection from disease, and can also preserve nutrients necessary for growth and retain moisture in the roots.

What is mulch?

Mulch is a layer of substrate that is used to cover the soil. It can consist of any organic material that is easy to decompose. In a forest, mulch is made up of what will decompose on its own in a given forest environment. This is usually leaves, undergrowth and woody plants. It also includes dead insects. All of these ingredients make up a mulch full of nutrients.

Benefits of mulching

The main benefits of mulching include:

Improved soil quality

Mulching helps loosen the soil and allows better air and water movement around the roots of plants. As the mulch decomposes, nutrients are released. The type of nutrients released depends on the mulch substrate used.

Better thermal insulation

Mulch provides reliable isothermal protection for the soil. It stabilises the temperature in the substrate. Helps protect roots in winter and maintain moisture in summer. A thick layer of mulch prevents water evaporation from the soil by forming a barrier between fertiliser-laden soil and hot climates.

A healthier environment

Helps the overall biological balance in the soil. As the decomposing material provides a home for beneficial microbes, bacteria and insects, it creates an ecosystem for them to thrive in. By maintaining the optimum soil temperature, mulch protects the garden from pests and bacteria.

What kind of mulch is best for cannabis?

Suitable mulch materials include:

shredded bark,
grass residues,
sawdust,
wood chips,
dry, crushed leaves and plant cuttings,
grass clippings,
straw.

While this material is the most common for mulching, it can be made from a variety of other materials. It's up to you which mulch material you use. The most suitable mulch is one that is a combination of different materials, making the most of their beneficial effects.

How to mulch cannabis?

Mulch is an important source of nutrients and also improves soil quality. However, the requirements of plants vary depending on their growth stage and growing conditions.

Woody mulch

Woody mulch, which is made up of shredded tree bark, is a suitable environment for fungi. If you have a chipper handy, crush the stems of last year's cannabis crop. These can help to reintroduce nutrients to the soil. It is best to use branches, bark or straw to acidify the soil and keep the pH in the ideal range needed to promote flowering and phosphorus and potassium uptake. In fact, fungi prefer a slightly more acidic environment, which is also suitable for cannabis during the flowering phase.

Fresh grass

In the early stages of growth, it is best to choose an organic mulch made from leaves and plant debris. This type of mulch is made up of freshly cut grass, leaves from last year's cannabis harvest and cut twigs, which are conducive to bacterial growth. Hemp in the vegetative phase benefits from a higher bacterial content, which contributes to better nutrient absorption. But make sure the mulch is free of pesticides or chemical fertilizers and free of any unwanted weeds.

It's also important to add nitrogen. A high nitrogen content promotes proper plant growth and development. Without nitrogen, the life of micro-organisms would be endangered. Micro-organisms are responsible for decomposing the bark, which is how nutrients get into the soil.