Cover crops are a great way to make your cannabis cultivation more environmentally friendly. They can help your soil be healthy, increase nutrient levels, keep pests away and reduce overall water consumption.
They also increase the aeration of your soil and improve its water retention capabilities through organic matter and root zone associations with mycorrhizal fungi. This helps to reduce evaporation and dry spells and preserve the terpenoids in your buds.
Benefits
Cannabis cover crops are a great way to improve the soil, reduce weeds and fertilize your plants. They can be planted during the winter, or grown between your main crops during the growing season. They are also useful in reducing the use of chemical inputs, such as pesticides and herbicides.
Choosing the right cover crop is crucial for your success. It needs to be a plant that will provide the benefits you need, such as weed suppression, soil health, and nutrient fixation. Some of the best crops for cannabis cultivation include buckwheat, mustard, rye grass and clover.
Cover crops can also act as a deterrent for pests and weeds, helping to discourage them from growing in your garden. These plants produce chemicals that deter insects and weeds from coming into contact with your cannabis plant, which can help to reduce the likelihood of disease and pest damage.
Marigold – A common deterrent, this flowering plant is an excellent choice because it produces a substance called pyrethrum that is toxic to many insect pests. It can be used to prevent aphids, whiteflies, and slugs from attacking your cannabis crop.
Basil – This plant is another good deterrent because it produces a substance called citral that can be toxic to certain pests. It can also be used to deter aphids, whiteflies, slugs and snails from coming into contact with your cannabis plant.
Buckwheat – This cover crop can be grown both indoors and outdoors, making it a great choice for marijuana growers who want to protect their plants from harsh weather conditions. It is a fast-growing cover crop that can be planted during the winter or spring, and it will quickly establish blooms and reach maturity in just 70 to 90 days.
Clover – This plant can be planted as a cool-season cover crop, as it can germinate and grow in temperatures as low as 34degC. It will survive frost and will also help to suppress weeds, improve soil health and reduce the need for chemical inputs during the winter.
The root systems of cover crops break up and aerate heavy, compacted soils, while at the same time enhancing the growth of beneficial microbes. These bacteria, along with mycorrhizal fungi, promote healthy soil structure by improving the aeration, drainage and nutrient cycling of the substrate. They also provide a habitat for nitrifying bacteria that fix Nitrogen to the soil. This provides your cannabis plants with the extra nitrogen they need to thrive.
Prevents Soil Erosion
Cover crops can help prevent soil erosion by enhancing the amount of vegetation on the soil surface. The vegetation helps hold the soil together and reduces the amount of water that is shed on the ground, according to research from Cornell University.
In addition, cover crops can improve the health of the soil by preventing erosion and increasing the soil’s microbial activity, which is essential for maintaining its overall nutrient balance. They can also reduce the impact of eroding sediment on waterways, which can cause flooding and mudslides.
There are several different cover crops that can be used in cannabis cultivation. These include legumes and grasses, which are known to fix nitrogen in the soil for the plants to use. They can also provide a source of biomass for the crop, which helps build up the nutrients in the soil.
Some of these cover crops also contain natural terpenoids that deter pests. These can help reduce the need for added pesticides in the garden, said Josh Turner, vice president of cultivation for Southbridge, Massachusetts-based Green Meadows, a vertically integrated marijuana company.
Other cover crops, such as mustard and buckwheat, can keep weeds at bay. They also help improve the soil’s microbial activity, making it more resilient to the stresses of growing cannabis.
These cover crops can be sown as a layer on top of the soil or planted in between crops. The depth of the cover crop depends on the type of soil. It is recommended to use a mulch of hay or straw at least 5cm deep, and preferably 10cm.
The mulch layer protects the soil from air and wind, keeping it protected and allowing for the growth of the cover crop. It can be replenished periodically as needed to maintain the optimal depth.
A diverse mix of cover crops is best, combining legumes and grasses for nitrogen fixing with broadleaf species like buckwheat, mustard, brassicas and more to suppress weeds.
These cover crops are a vital part of the ecosystem, supporting a wide range of organisms, including earthworms and beneficial insects. They also add organic matter to the soil and help break up compacted soil, which promotes better aeration and water distribution. This is especially important in areas with poor soil quality, which can result in the loss of nutrients from the soil and the water that flows through it.
Reduces Weed Growth
Cover crops, especially those that are incorporated into a crop rotation system, reduce the number of weeds that will grow in the next season. This can result in fewer herbicide applications, as well as lower costs to producers.
Some cover crop species are even allelopathic, meaning they produce chemicals that suppress the germination of weed seeds. Generally, these chemicals act by decreasing the intensity of light that reaches a weed seed’s surface.
This reduction in light availability also prevents weeds from acquiring the nutrients they need to germinate. This decreases the weed population density, which can then lead to fewer herbicide applications and less risk of resistance.
Another way that cover crops reduce weed growth is by altering the composition of soil microorganisms. When a cover crop is tilled into the soil, it stimulates a flush of microbial activity that can make the soil temporarily inhospitable to most weeds and crops (Kumar et al., 2008).
These microorganisms can immobilize plant-available soil N and deprive weeds of the nitrogen they need to germinate. They also dampen off fungi and other pathogens, which can attack weed seedlings.
Some cover crops, such as cereal rye, also suppress weeds by producing compounds that inhibit the growth of other plants that are growing nearby. These allelochemicals can suppress a variety of weed species, including the problematic Amaranthus tuberculatus, for example.
However, it is important to note that cover crop biomass must be sufficiently high in order to consistently achieve weed suppression. Research has shown that corn and soybean planting dates influence cover crop biomass accumulation. In areas like central Iowa, the fallow period between cover crop plantings limits how much biomass can accumulate before the usual cropping season starts.
For this reason, it is critical to scout fields to determine the uniformity of cover crop biomass prior to using them in a rotation. If cover crop stands are uneven, weeds may be able to escape the stand and gain control in the next season.
Increases Nutrients
Using cover crops in cannabis cultivation increases the amount of nutrients that plants can absorb. These nutrients are essential for a plant’s ability to grow and thrive, and they also help protect plants against pests and diseases.
While there are many different ways to use cover crops in cannabis cultivation, two of the most common are crop rotation and incorporating winter cover crops. Both of these practices promote soil health and biodiversity, and they can be used by both outdoor and indoor growers.
Crop rotation is a practice that involves planting different types of crops in the same area over time, and it has been shown to improve soil health and reduce pest outbreaks. This is especially effective for cannabis cultivation, as it can prevent soil depletion and increase the number of plants that are able to survive in a given space.
Another way that cover crops can increase nutrients is through their ability to fix nitrogen from the air. Nitrogen is one of the most important nutrients for plants, and if a plant does not have access to it, it will stop growing. This is why it’s important to choose cover crops that are able to “fix” Nitrogen from the air, such as clovers and legumes.
This practice is not only beneficial for improving long-term soil fertility, but it also saves growers money by not needing to fertilize as often as they would otherwise. The nitrogen that is fixed by a cover crop can then be slowly leached into the soil for the main plant, so you’ll only need to fertilize the plant when it needs it.
Additionally, cover crops can provide organic matter to the soil, which is vital for building soil health and preventing erosion. They can also help to suppress weed growth, and they provide a habitat for beneficial insects, which can protect plants from pests.
As a result of these factors, many commercial growers are using cover crops to produce their cannabis products. These crops can be planted as either green manure or under perennial crops. It’s also a good idea to check the local ordinance and state regulations for your specific area before trying this practice, as it may be illegal in some places.
