However, plants grown in pots, buckets, or barrels will likely be smaller than those planted in the ground because their root growth is restricted to the size of the container. In a broad sense, the size of the pot will determine the size of the plant, although it’s possible to grow large plants in small containers if proper techniques are used.
Heavy clay soils drain slowly and don’t hold oxygen well, so they will need to be heavily amended. A few weeks before you plant, dig large holes where you’ll be placing your weed plants and mix in big amounts of compost, manure, worm castings, or other decomposed organic matter. This will provide aeration and drainage, as well as nutrients for the plants.
Cannabis plants require a large amount of nutrients over their life cycle, mainly in the form of nitrogen, phosphorus, and potassium. How much you need to add to your plants will depend on the composition of your soil.
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.
Buying the right soil for an outdoor cannabis grow
Here are some important considerations before starting an outdoor marijuana grow.
Garden plot: Probably the most common outdoor growing spot, many will plant cannabis alongside other growing veggies.
Soil also varies in:
Most outdoor weed growers will either dig a hole and add fresh soil for the plant, or grow their weed in pots. This will allow you to better control the growing medium and the amount of nutrients your plants receive.
Organic fertilizers are nutrients that come from organic sources such as animal and vegetable waste. They also include sediments like glacial rock dust and gypsum that contain beneficial minerals for the soil and plant. They are common for outdoor growing and usually come in powder form.
It’s important to get a pH meter to check the pH level of your water when mixing nutrients. Cannabis prefers a pH between 6 and 7 in soil, and between 5.5 and 6.5 in hydroponic media. Letting the pH get out of this range can lead to nutrient lockout, meaning your plants are unable to absorb the nutrients they need, so be sure to test your water regularly and make sure the nutrient mix you give plants falls within the desired range.
Products are also generally divided into “grow” solutions, high in nitrogen needed for vegetative growth, and “bloom” solutions, high in phosphorus for flower development. You can stick to these general terms if you don’t want to get bogged down with numbers.
Organic cannabis fertilizers
Magnesium acts as the central molecule in chlorophyll and without it, plants aren’t able to generate the glucose from photosynthesis. No magnesium means no energy can be converted from sunlight.
To use liquid nutrients, you’ll need a separate water tank, such as a dedicated garbage bin, to mix them into water. You’ll also need to know how much water is needed for all your plants. Depending on the amount of water you need, add the correct ratio of liquid nutrients according to the bottle’s directions.
Comparing nutrient and fertilizer brands
Potassium also triggers the production of ATP, which works to store energy produced in photosynthesis by creating glucose. This glucose is then used as energy for the plant as it grows. Without sufficient potassium, you will see weak plants starved for energy that appear burnt because they are unable to successfully regulate the exchange of CO2, H2O, and oxygen.
A general rule of thumb is that a vegetative fertilizer should have high nitrogen, low phosphorus, and moderate potassium: for example, 9-4-5. As a plant transitions into flower, taper off the nitrogen and focus on phosphorus and potassium—seek a ratio around 3-8-7, for example.