Cannabis seeds are a great source of nutrients and contain the plant’s genetic code. They grow from pollinated flowers on female plants and can be eaten or used in smoking, but they don’t have any of the psychoactive or medicinal properties that we associate with weed.
Spontaneous hermaphroditism occurs frequently in cannabis plants. The stigmas of hermaphroditic flowers develop receptive papillae and collapse around a central core (anther).
Germination
Cannabis seeds require warm, dark and humid conditions to sprout. The best time to germinate them is during the Spring equinox if you’re growing outdoors. Using an indoor growing setup though allows you to germinate them whenever you want, as long as the environment is a good match for their natural growth conditions.
Soaking seeds in water works well, especially for the older seeds with harder shells that may need a wake up call. Soak the seeds in a glass of room-temperature water for 12 hours and store them in a dark place.
The main drawback to this method is the risk of damage to the seeds as you move them from one container to another, and the seeds can dry out and die if not kept in a damp towel or between two plates. If you use jiffy pellets or seedling cubes, they already come moistened so there’s less of a risk of damage when moving the seeds.
Soil
Using soil that is rich in nutrients and beneficial microorganisms is the foundation of growing cannabis. The nutrient pool of the soil enables plants to grow from cute little seedlings to healthy, productive adult plants with a canopy of dank buds.
Use sterilized potting soil, organic compost or a mix of organic topsoil and non-peat potting soil. Add perlite to any mix you choose – these light airy “rocks” increase drainage and oxygen levels.
Do not buy soil that has a lot of big visible wood chip fragments in it – the chips keep water and nutrients from reaching the plant, so the plants struggle.
There are a few brands of potting soils that are specifically formulated to work well for plants like cannabis. These “super” soils contain mycorrhizae, kelp, fish bone meal, worm castings and lobster compost that provide slow-release organic nutrients that see the plant through its entire growth cycle – no need for additional chemical nutrient supplements.
Water
During the flowering phase of cannabis, plant growth can require a lot of water. For this reason it’s important for the grower to have a good idea of how much water they are using. A hygrometer can help to give an accurate reading of the moisture in the soil or growing medium.
Generally speaking, cannabis seeds like to be kept in moderately dry conditions. Too much water can cause the seeds to rot and die.
When it comes to purchasing cannabis seed, it’s always best to choose a trustworthy seed bank with a great reputation. ILGM, Beaver Seeds, and Crop King Seeds are some of our top picks for their customer service, high germination rates, and reasonable prices.
When it comes to watering cannabis plants, distilled or filtered water is ideal. Bottled water often contains added minerals and nutrient levels which can stunt plant growth. A pH level of 7.0 is ideal for cannabis root zones, and it’s also recommended to use a hygrometer to ensure the right amount of water is being used.
Stone Wool Blocks
Stone wool (rockwool) is a popular hydroponic substrate used by cannabis growers. It’s made from molten rock spun into cotton candy-like fibers that are then compressed into a variety of shapes and sizes – from plugs to blocks to slabs, all tailored to different plant stages and cultivation methods.
Unlike peat and coco coir, which can be contaminated by fungal spores, pests and other carbon-based organic material, Grodan stone wool is highly consistent and inert. It also has a higher water uptake capacity than soil and a more uniform texture that allows for better root zone management during vegetative growth.
Cultivators using Grodan Grow-Cubes and Grow-Slabs for clonal propagation find that their consistency from planting to transplanting supports precise root zone management and tightly choreographed vegetative growth. They can also count on consistent size and structure for a smooth integration with automation systems to reduce labor costs and facilitate data collection that maximizes facility productivity.
