Brief Overview of Cannabis Genetics

There are many varieties of cannabis, but typically three main types are distinguished: Cannabis sativa (native to tropical climates such as Africa, Latin America, Thailand, etc.), Cannabis indica (Afghanistan, Pakistan, etc.), and Cannabis ruderalis (mainly wild fields in Eastern Europe: Ukraine, Russia, etc.). In this guide, I will focus only on three types: Cannabis sativa, Cannabis indica, and their hybrids.

You might ask, “What about our native variety?” Unfortunately, it doesn’t quite measure up. If you decide to grow it, my advice is: “Plant it only outdoors, as its only advantage is a short flowering period.” Industrial hemp is mostly Cannabis sativa, grown for fiber, paper, fuel, and many other useful products. In some countries, like Germany since 1995, hemp cultivation and production have resumed.

Cannabis sativa tends to grow very tall with narrow, long leaves. It also takes a long time to mature and often produces a moderate yield. Cannabis indica tends to stay moderately tall, has a bushy shape with very broad leaves, matures earlier, and forms thick, resinous buds. Cannabis indica has the highest resin coverage on its buds, which is why the best hash is always made from 100% indica. These two types are also distinguished by their effects: indica is very calming, almost narcotic (Americans call this state “stoned”), while sativa gives an active, energetic, cerebral effect (“high”).

What you prefer is a personal choice, but today, most high-quality strains, such as those from the Netherlands, are hybrids. I strongly recommend growing these: if you start with “A” class seeds, even with less-than-perfect results, you’ll end up with “B” class weed, but if you start with “B” class…

For example, Skunk #1 (50% Colombia, 25% Mexico, 25% Afghanistan), bred by Cultivators Choice, is mathematically 75% sativa and 25% indica, but the effect is sativa-like, and the plant stays short and yields well. Thanks to Dutch seed companies for their careful and meticulous breeding.

The Cannabis Life Cycle

At the beginning of its life, cannabis needs long days to grow vegetatively (in height, width, and leaf production). When the plant receives long days, it doesn’t produce flowers (buds) but grows taller and develops new leaves. Under continuous light (24 hours a day), the plant can theoretically grow indefinitely (for several years) without showing flowers.

Female plants (as you know, each cannabis plant is either male or female) start flowering as soon as they receive the necessary amount of darkness. Equatorial sativas require longer periods of uninterrupted darkness (12–13 hours) than indicas (10–12 hours). Remember, the most important thing for flowering is uninterrupted darkness—even the light of a full moon can disrupt this delicate process! In complete darkness, cannabis begins to produce a hormone that is quickly destroyed by light.

If you grow cannabis outdoors, knowing the life cycle isn’t as crucial; you just need to choose a strain suited to your latitude. But for those who want to grow top-quality cannabis at home, being able to manipulate the plant is essential.

Germinating Seeds

Germinating seeds is usually not a problem: 90% of high-quality seeds sprout successfully. To germinate seeds, take a saucer (or something similar) and two pieces of cotton (or paper towels). Pour enough water into the saucer to soak both layers of cotton, place the seeds between them, and check daily to ensure the cotton doesn’t dry out. Put it in a warm place to speed up germination. Seeds should show a small white root within 24 hours or up to 7 days. Once the root appears, plant the sprout in soil at a depth of about 0.4–0.6 inches (1–1.5 cm). In 2–5 days, you’ll see the first shoots.

Remember the recommended germination temperature: soil temperature should be between 75–80°F (23.8–26.6°C), and air temperature can be 5–9°F (3–5°C) lower.

Transplanting Seedlings

To achieve the desired number of plants, always plant more seeds (some may not sprout, others may be male). For germination, you can use small pots (a cut plastic bottle or milk carton works). To minimize transplant shock, transplant after 5–7 days, while the main root is still small and less likely to be damaged.

Transplanting a small seedling is easy: take a large spoon, insert it into the soil 0.8–1.6 inches (2–4 cm) from the stem and 2–2.8 inches (5–7 cm) deep, and press down on the end of the spoon like a lever. Place the resulting soil clump into a new pot (the soil should be wet) so the stem is at the same depth as before. Water thoroughly.

Remember, transplanting is a major shock for plants and slows their development, so try to transplant only once per cycle.

Sex Differences

As you know, each cannabis plant is either male or female. If you’ve smoked marijuana, you probably know that the highest THC content (the active substance people seek) is found in the female flower (in this guide, seedless female flowers are the number one goal). Why seedless (sinsemilla)? Because this is the most potent part of the plant. When a female flower is pollinated, all its energy goes into producing seeds. If the flower is not pollinated, it continues to grow new flowers and its potency increases significantly. “Commercial growers” produce seeds (which contain no THC) because they only care about the weight of their product—not the consumers, right?

What you do with the males is up to you, but remember, the potency of the leaves does not depend on the plant’s sex. If you plan to keep female leaves, male leaves are just as good. Also, male flowers (though there are few) are 3–4 times stronger than the leaves from the same plant.

To get high-quality sinsemilla, you must remove all males before they release pollen. One male flower can ruin all your females—don’t give them a chance! Before you’re left alone with your “girls” (not bad, right?), you need to learn to identify the males early. It’s not that hard—just give them a little time to develop. You have enough time before the male flowers open and start their mischief. The simplest and best way is to look for two small (0.2–0.4 inch / 0.5–1 cm) “antennae” in a V-shape growing from each small female flower (bud). Male and female buds look the same, but only the female bud has antennae growing from it. The first flowers always appear on the main stem where leaves and branches grow out.

On average, cannabis plants are 50% male and 50% female (out of ten plants, five are female and five are male). This ratio also depends on the strain and environmental factors.

Fertilizers

As I mentioned, all my friends (not just in Russia) grow cannabis only with organic fertilizers. I won’t list all the advantages of this method and leave the choice up to you. I think an experienced gardener should try everything and make their own decision. I’m almost sure you’ll choose organics over chemicals. Ask for only organic fertilizers at garden stores.

Organics

You can grow completely healthy cannabis without adding fertilizers (especially outdoors). But to increase yield, speed up growth, and prevent nutrient deficiencies, a small amount of fertilizer is recommended. When preparing the soil, add some manure (chicken, horse, etc.). Don’t use manure from your own garden, as it often contains insect eggs that can destroy your efforts—buy special manure from the store (it’s a bit more expensive). If you can’t find this in stores, don’t worry—there’s an alternative. Add wood ash and urine (yes, your own urine, as it’s rich in nitrogen) to the soil (but don’t overdo it). Both options provide everything the plant needs throughout its life.

Remember, the plant needs plenty of air. Mix soil in pots as follows: 60% good, fertilized soil and 40% sand or (if you can find it) perlite. After 2–3 weeks of vegetative growth (if there’s no sign of fertilizer overdose), add a bit more nitrogen (urine). Experiment!

Add the recommended amount of fertilizer to one plant, double the amount to a second, and none to a third. Keep records—next time, you’ll know exactly how much fertilizer your plants need.