The life cycle of marijuana plants. See which phases they go through.

Everything that is alive on this planet, has a life cycle and follows a life path. The marijuana plant starts off as a single seed, to become a seedling, kicks off the vegetative growth stage and eventually reaches the flowering stage.

Germination of marijuana seeds

Germinate your seeds in sterile soil when you grow outside. You can also use a hydroponic medium of rockwool or vermiculite.

Planting in vermiculite gives the marijuana seedling a lot of oxygen and the roots of the plant love it. Rockwool cubes also work extremely well. When the marijuana seed sprouts, place the rockwool cubes into larger rockwool cubes. No repotting or transplanting and no soil mixing!

You can germinate marijuana seeds just by placing them in a bowl or plastic cup with a little water at the bottom. Then cover it with plastic wrap to keep it from drying out. Put the bowl in a warm area... for example on top of the gas stove, the water heater or close to warm lamps. Check regularly if it is still moist.

Once the root has come out (about 1 to 2 inches), put the germinated seed with the grow tip up in a growing medium. Be very gentle and do not touch the root tip.

It is best to transplant as little as possible by germinating in the same container as you intend to grow the marijuana plant in. Then you reduce the risk of damaging your little plant.

It depends on where you live, but often there are substances like chlorine in normal tap water that can damage your baby plant. So be sure to use distilled water, when germinating your seeds. You can also buy bottled water from the supermarket.

Warm temperatures are very important. Many marijuana growers experience low germination rate if the temperatures are out of the range of 72 to 80°F (22 to 25 °C). So keep things nice and warm, just compare it to a warm summers day.

Germinating marijuana seeds don’t have to be in direct light, but seedlings do, once they have sprouted. Plan on transplanting as little as possible by using the biggest containers possible right from the start.

Vegetative growth of the marijuana plant

Once sprouted, the marijuana plant starts the vegetative growth. This means the marijuana plant will be photosynthesizing as much as possible to grow tall and start many grow tips at each pair of leaves.

It is possible to grow marijuana plants with no dark period, and increase the speed at which they grow by 15 to 30 inch (37.5 to 75 cm). A cannabis plant can grow from 12 inches to 12 feet (30 cm to 3 meters) before being forced to flower, so there is a lot of latitudes here for each gardener to manage the garden based on goals and space available. It is up to the gardener to decide when to force the marijuana plant to flower.

The flowering period of a marijuana plant

The marijuana plant will be induced to flower with dark cycles of 11 to 13 hours that simulate the oncoming winter in the fall as the days grow shorter. There is no other requirement other than to keep the dark cycle for flowering very dark with no light interruptions, as this can stall flowering by days or weeks.  

Once a marijuana plant is big enough to mature (12 inches/ 30 cm or over), dark periods are required for most marijuana plants to flower. This will require putting the lamp on a timer, to create regular and strict dark periods of uninterrupted light.

In the greenhouse, the same effect can be created in the summer (long days) by covering it with a blanket to make longer night periods.

A strict schedule of covering the marijuana plants at 8 pm and uncovering them at 8 am for two weeks will start your marijuana plants to flowering. After the first two weeks, the schedule can be relaxed a little, but it will still be necessary to continue this routine for the marijuana plants to completely flower without reverting back to vegetative growth.

Outdoors, in spring and fall, the nights are sufficiently long to induce flowering at all times. Merely bring the marijuana plants from indoors to the outside at these times, and the marijuana plants will flower naturally. In late summer, with fall approaching, it may be necessary only to force flowering the first two weeks, then the rapidly lengthening nights will do the rest.

When most of the pistils have turned color, the flowers are ripe to harvest. But don't touch the buds as the THC will come off on your fingers and reduce the overall yield. If you want to inspect the buds just hold on to the big leaves, so nothing will be damaged.

Add high-quality fertilizer to your growing medium

If you give your plant extra nutrients, it will become stronger and produce a higher yield. So add high-quality fertilizer to your growing medium in each growth phase your plant is in.

Marijuana plant flower