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.
Becoming intimately familiar with your local climate and seasons is one of the most important steps in producing high-quality outdoor marijuana. Before you grow, you’ll need to know the ideal temperature your plants require in order to thrive, the best site, optimal timing of planting and harvesting, and the season’s photoperiod — the amount and intensity of light available through the duration of the growing season.
Using Mother Nature to cultivate cannabis
If you live in a climate with exceptionally hot and sunny days, use shade cloth to prevent your plants from overheating. In cold areas, natural enclosures and cement or brick walls can be used to help retain any available heat and keep your plants warm.
You can plant directly into the ground, using the preexisting soil, but you’ll need to understand your soil’s composition and amend it accordingly. If you go this route, we recommend getting your soil tested, which will minimize headaches, and it’s easy and relatively inexpensive. A soil test will tell you the makeup and pH of your soil, any contaminants present, and will recommend materials and fertilizers to amend your soil.
You may need to put all of your plants in containers if you don’t have great soil. Also, if you’re unable to perform the heavy labor needed to dig holes and amend soil, containers may be the only way for you to grow your own cannabis outdoors.
Soil, at a basic level, is defined as the topmost layer of earth in which plants grow—it’s a mixture of organic remains, clay, and rock particles. Cannabis plants thrive in soil rich with organic matter, and they need good drainage.
Soil and other media for outdoor cannabis growing
While shopping for soil, you might be overwhelmed by the options available at your local garden store. The soil type is the basic structure of your soil. From there, look at nutrients, microorganisms, and other amendments that improve the soil. Your choices will be flooded with words like:
In general, 5-gallon pots are a good size for small-to-medium outdoor plants, and 10-gallon pots or larger are recommended for big plants. Regardless of size, you’ll want to protect the roots of your plants from overheating during warm weather, as pots can quickly get hot in direct sunlight. This will severely limit the growth of your plants, so be sure to shade your containers when the sun is high in the sky.
Buying the right soil for an outdoor cannabis grow
Relying on the power of the sun, you won’t need to spend a ton of money on an outdoor grow. You’ll need some soil, fertilizer, seeds or clones, and maybe a small greenhouse to get them started. You won’t need to pay for electricity for lights, AC units, or dehumidifiers, and you can even collect rainwater.
These are just some examples of amendments commonly used in different types of soils. Heavily amended soils will have long lists that break down all organic nutrients they contain. Some companies create soils that offer a great structure with base nutrients, but allow you to fill in the gaps as you desire.
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.
Four basic soil types exist: sand, clay, silt, and loam. Each has its pros and cons for gardening.
Just like humans, plants need the right nutrients. The most important ones for your cannabis plants are nitrogen (N), potassium (K) and phosphate (P). These make up the ratios you will typically see on fertilizer labels.
You will want to provide the proper amount of light and water to your plants, of course. A drip irrigation system can cut your water bills while improving the health of your plants. Kits are available that give you everything you need to get started. If you prefer, you can start from scratch and obtain separate components to put them all together.
Loam for Growing Marijuana & Other Crops
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.