Avoid all-in-one fertilizers as they can be too high in nitrogen for the flowering cycle and damage any beneficial microorganisms that may be present in the soil. Instead, choose a line of nutrients created specifically for cannabis, and use its suggested feeding charts to avoid over- or under-feeding. Organic sources of nutrients are best, as they are a great source of beneficial microbes, but they may take longer to break down and become available to the plant. Both types of nutrients can be found in dry, pre-blended powders or liquid emulsions, but can also be made from scratch with the right ingredients. Organic compost tea, which includes nutrient-rich ingredients, like molasses and earthworm casting compost, is a popular homemade brew for cannabis farmers.
Greenhouses also offer growers the ability to harvest more than once per year, if they are equipped with a light deprivation system. These systems allow growers to control the hours of sunlight their plants receive, much like turning lights on and off in an indoor garden, by covering the greenhouse with a black tarp that deprives the plants of sunlight.
Plan to put plants in the ground based on the temperature, season, and light where you live so your cannabis plants have time to finish flowering before cold, rainy weather sets in.
Containers vs. in-ground
Cannabis requires more nutrients than many of the other plants you may have in your garden. Quality soil contains enough organic nutrients to start the growth cycle, but as your cannabis plant grows and transitions into flowering, it may deplete the available nutrients and require additional fertilizers.
Whether using seeds or clones, many cultivators start growing their plants indoors to ensure they are not exposed to damaging weather conditions as they develop their initial root system. The plants can be transitioned outdoors when the weather and light conditions are ideal. Extending the indoor vegetative growth period can help increase yields and allow growers time to select the best plants to be moved outdoors.
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.
Greenhouse structures range from inexpensive polyvinyl chloride (PVC) tubes, often called “hoop houses,” to highly engineered, fully automated, and purpose-built steel greenhouses. Due to their efficiency, greenhouses are quickly becoming the preferred growing method for many large-scale cultivators.
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.
We also advise against using nutrients designed for indoor weed growing—they are generally composed of synthetic mineral salts and can damage soil bacteria.
We recommend these organic fertilizers:
It’s crucial to have a good understanding of the climate in the area you’re going to grow. Cannabis is highly adaptable to various conditions, but it is susceptible in extreme weather.
Buying the right soil for an outdoor cannabis grow
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.
Garden plot: Probably the most common outdoor growing spot, many will plant cannabis alongside other growing veggies.
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.
What size pot do I need?
The best way to identify loamy soil is by touching it. How does it feel? Sandy soil should be difficult to compact while clay should compact into a tight ball that won’t crumble. When squeezed, loamy soils should form a loose ball that will hold its structure momentarily before breaking apart in large chunks.
Sustained temperatures above 85°F will cause your plants to stop growing, while continued temperatures below 55°F can cause damage and stunting to plants, even death.
Native soil is different everywhere, and the levels of fertility and drainage vary greatly from place to place. Your best bet is to send away some soil samples for testing so you’ll know exactly what you need to do to make it better. I believe in no-till gardening, meaning you just continue to place composted material on top of your soil without ever having to dig it up. Some growers recommend digging up the soil the first time you plant in it, but this is dependent on how rich your soil is in the first place.
It’s easy to get a decent harvest of outdoor buds as long as you take certain factors into account. The most important aspects are the amount of direct sunlight your plants will receive, the genetics of the plants you choose to grow and the care with which you harvest, dry and cure your finished branches. So be sure to find a good space to put your plants, choose great seeds or clones of known origin, and put an emphasis on your processing techniques when your plants are ripe.
I’ve done small grows the past two summers so I’m basically a beginner. I just want to be able to grow the best marijuana I can outdoors. I want it to be the bushiest plants with the best yields and highest THC levels. I hope to get serious in the marijuana business not just because I love smoking it, but I hope to grow marijuana for medical use to help other people. If there are any tips on what soil I should use, what I should put in the water, or anything special I can do to help grow more and bigger buds with higher THC, I would appreciate it. — Conner
As for the water, plants in good soil and full sun will need a lot of it. Use plain water often but also plan for feedings with a nutrient solution. I prefer organic formulations and always advise using less than the recommended amounts unless you’ve detected a deficiency. Drip systems work quite effectively on outdoor plants, delivering a near constant supply of water without over doing it and reducing the amount of water wasted to evaporation and overflow.