Modified on: 10/02/2021
The 5 tips about the best soil for sowing marijuana.
Are you wondering how to plant marijuana to get a good plantation? First of all, we want to remind you that in the UK you can only plant industrial cannabis (THC weed seeds cannot germinate). Secondly, you must know that the soil is a fundamental aspect of excellent cultivation.
What should you look for in the soil for hemp plants?
Most hemp crops – light and high THC level and content in those countries where it is possible generally, choose a dark, soft and well-drained soil. It means that it should absorb water from watering without becoming muddy.
If we want to go into the specifics, you will find in the article 5 crucial information about the suitable soil for planting cannabis seeds!
But be careful: what you read next is for information purposes only. We do not suggest to put it into practice because in Italy the germination of THC marijuana seeds is not allowed. However, you can rely on this information if you intend to grow light cannabis (or cannabis with high THC content in countries where cultivation for personal use is allowed).
1) There is a particular soil for planting cannabis for sale!
But in reality, this land is not indispensable and could be too expensive. Growers usually simply choose a good ‘generic’ soil in which to plant auto flower seeds, feminized seeds or regular cannabis seeds and fertilise it regularly.
You can add nutrients directly into the soil (using natural fertilisers such as vermicompost, called worm tea) or dissolve the nutrients in watering water.
But which basic soil to choose when planting marijuana seeds?
Any mixture of organic soil is fine (of course it must be suitable for sowing). Just ask for the best soil in a garden shop or nursery, and you’re done!
2) The soil for cannabis seeds must be strictly organic.
Organic potting soil is free of substances that are harmful (or potentially harmful) to both marijuana seeds and plants and flowers, such as slow-release chemical fertilisers. Growers, using organic soil, add organic nutrients when the cannabis seedlings begin their vegetative phase, the growth phase, during which the roots rapidly consume all the nutrients.
Usually, during the germination of hemp seeds, which precedes the vegetative phase, no additional nutrients need to be added to the soil.
Organic soils are usually dark, rich and incredibly soft: a sowing soil is never too dry and muddy! Do not disdain those with perlite, i.e. small white pebbles that make the soil even more draining.
3) Plant marijuana in the ground? Drainage is essential!
Whether you want to plant the outdoor weed seeds directly into the ground or you want to sow them in pots, the drainage capacity of the soil is critical, perhaps even more so than the nutrients in it.
For the best marijuana seeds to germinate and for the plant to grow and flower without difficulty, the roots must be both well hydrated and well-oxygenated as they can dry out very quickly. Likewise, they should not be exposed to water stagnation as they would rot very quickly.
So, the best soil for growing cannabis has to be light, water-restricted, but the water must not
stagnate! For this reason, muddy soils are not recommended: they leave the roots moist for too long and make them rot.
4) Here is what to add to a basic potting soil for cannabis seeds.
The perfect soil for sowing and growing cannabis is very light, draining and dark. At first glance,
it must appear “alive” and give off a fresh and pleasant smell (never prone to mould!). Besides, you can add materials and substances that make it even more suitable for hemp seeds.
Here are which ones:
- Perlite: white stones that increase the drainage capacity of the soil and increase the oxygen supply. The quantities of perlite to be added can range from a minimum of 10% to a maximum of 40% of the soil volume. Those who intend not to use a lot of extra nutrients usually add little perlite, those who intend to add proper amounts of natural fertilisers during plant growth typically use high quantities of these pebbles.
- Vermiculite (different from vermicompost): this material improves the soil’s ability to retain water and nutrients and lightens the soil. Those who add both vermiculite and perlite (recommended) should never add more than 50% of the total soil volume.
- Coconut fibre can be purchased either in small blocks to be hydrated or in shavings to be used as they are. Coco coir improves the absorption capacity of the soil without weighing it down. It promotes a fast development of the cannabis plant’s roots and at the same time prevents the rootlets from suffering from an excessive water supply. Growers usually add coconut fibre in quantities ranging from 10 to 30% of the total soil volume.
- Vermicompost (earthworm humus), an excellent biological fertiliser obtained from the digestive waste substances of worms. This substance dramatically nourishes the soil and improves its quality, as it contains many beneficial substances and good microorganisms present in the digestive system of earthworms. Growers usually add 30% of vermicompost to the soil.
Now we see all the characteristics of good potting soil for sowing cannabis.
5) The ideal potting soil composition for cannabis seeds.
Perfect soil for growing marijuana seeds is organic, dark, alive and fertile. It is also very soft,
well-draining and absorbs water quickly without becoming muddy.
Here are the ingredients for an ideal potting soil (they may already be present in the base soil, or you can add them yourself):
- Sandy” soil.
- Acidic sphagnum peat.
- Coconut fibre.
- Earthworm humus / bat / guano or other natural fertilisers.
- Dust such as dolomitic lime, azomite, leonardite and others.
It looks a bit like a magic potion, but it’s what it takes for cannabis seeds to germinate well and seedlings to grow and bloom luxuriantly! Daily and not excessive watering and an adequate supply of light help to make a cannabis planting profitable.