Sand is easily permeable for root growth, for instance, but it does not hold on to water or fertilizer well.
The optimal ratio for loam is 20% clay, 40% silt and 40% sand. Most folks think a pH of 6.0 is best for cannabis, with a range of 5.8 to 6.3 being acceptable. With a pH close to neutral, loam is typically in that zone or close to it.
Of these types, loam is by far the best soil mix for growing marijuana plants and many other types of crops. Loam is a mixture of clay, sand, and silt, bringing forth the best qualities of these disparate types of soil while minimizing their worst attributes.
Loam for Growing Marijuana & Other Crops
Clay is just the opposite. When it’s hot and dry, clay can become hard as a rock, making it difficult for roots to penetrate. Clay drains poorly and is hard to cultivate. On the plus side, it is rich in minerals and natural nutrients.
Greenhouses can be a great middle ground between the complexities of an indoor setup and the uncertainty of growing outdoors. They provide ample protection from the elements and use far fewer resources than an indoor grow. Greenhouses can be more costly than an outdoor garden and require more planning, but they also allow you to extend the growing season considerably.
Plants grown from seeds are typically heartier and more vigorous than clones, as they produce a sturdier taproot that clones are not able to replicate. Photo by: Gina Coleman/Weedmaps
Plants grown from seeds are typically heartier and more vigorous than clones, as they produce a sturdier taproot that clones are not able to replicate. The vigor that comes from deep roots can be an advantage when dealing with harsh environmental conditions and pest pressures. The disadvantages of growing seeds are the additional attention required to germinate the seeds, the necessity to eliminate any males before they pollinate the females, and the high variability in growth characteristics that results from their genes.
Depending on your location, you may need to plan for rain. In most regions, the rainy season is typically aligned with the end of the flowering stage and the start of the harvesting period, but this may not always be the case. Rain can be detrimental to an outdoor flowering crop so being prepared to cover or move plants can help ensure a successful harvest. If it does rain on your plants, make sure to immediately shake off any excess water, as lingering moisture can lead to the formation of mold and nobody likes moldy weed.
Pest and weed control
In the Northern Hemisphere, cannabis can be planted in early to mid-spring and harvested in mid-fall, depending on the cultivar. In the Southern Hemisphere, the growing season will be reversed with planting in early to mid-fall and harvesting in the middle of spring.
Container gardens can be convenient as plants can be moved around the garden to maximize sunlight or protect them from harsh conditions such as rain, heavy winds, or extreme temperatures.
Daytime temperatures between 75 and 85 degrees Fahrenheit (23.9 to 25.4 degrees Celsius) are ideal for cannabis, while temperatures above 88 degrees Fahrenheit (31.1 degrees Celsius) or below 60 degrees Fahrenheit (15.6 degrees Celsius) can delay growth. Cannabis is considered heat-tolerant, but sustained highs and extreme lows will usually lead to complications that could eventually kill your plants.
Planning your garden
Avoid clay pots as they can be costly, heavy, and retain heat that could dry out the plant’s soil and roots. Fabric pots are the least expensive and most effective solution, as they allow for ample drainage and plenty of oxygen to get to the roots. Plastic containers are also light and inexpensive but tend to retain more heat than fabric pots. Flowering plants need a container that is at least 5 gallons (18.9 liters) to prevent them from outgrowing their containers and becoming rootbound.
Cannabis is a hardy plant that has adapted to climates all over the world. From the cool and arid mountains of Afghanistan to the humid regions of Colombia, over time the plant has been forced to adapt its defenses against a host of problems. But cannabis is still susceptible to extreme weather conditions. Whether it is heavy winds breaking branches or excessive rain causing mold, the great outdoors presents challenges to growers that can be mitigated with sufficient planning.