Surely you have already wondered when and how you should harvest your cannabis plants. With this article we seek to help you solve all your doubts, guiding you step by step so that you get to know how and when you should do it.
When is the optimum time to harvest?
The flowering stage usually lasts about eight weeks in total. During this period of time, flowers and resin are produced. To know when this flowering period ends, we will observe that the plants no longer develop new flowers and the production of resin stops. This is when the time to harvest approaches.
However, a few weeks before the optimum harvest time there are already formed buds, but you have to be patient, because it is during the last weeks of flowering that the buds get fatter at a higher speed. The last weeks are very important to ensure that the plants achieve the highest possible production and the highest level of THC. If they are harvested before the ideal timing the buds will have less psychoactive effects and will also be less aromatic.
Does the time of harvest vary according to the variety?
Depending on the variety we grow, the harvest date may vary. Here we detail the harvest periods according to the type of variety:
|Variety Type||Indoor Grow||Outdoor Grow|
|Photoperiod-dependent||Between 7 and 9 weeks.||Depending on the strain it may vary between September and October.|
|F1 Fast Version®||Between 6 and 7 weeks after changing the photoperiod to 12/12.||Maturity occurs 1 to 2 weeks earlier in regards to the original versions.|
|Autoflowering||From 7 to 9 weeks from germination.||From 7 to 9 weeks from germination.|
Choosing the harvest day
There are two ways to decide when to harvest:
1. Observing the stigmas/pistils: This is the simplest and easiest method. It consists of looking at the stigmas (pistils) of the flowers. When more than half of the stigmas (white or pink hairs) have changed to brown, the plant is very probably ready to be harvested. According to the variety and to the taste of each grower, the plants can be harvested when there are 60 to 90 percent of brown stigmas.
2. Observing the color of the trichomes: This is a more accurate and at the same time more laborious method. It consists of observing and controlling the color of the resin glands (trichomes). The resin, which contains THC, is in the glands that cover the flowers. These glands are transparent while they continue to produce new resin. When they stop doing it, they change color, first acquiring a yellowish tone and then reaching to an amber tone.
You can keep track of this color change with the help of a microscope or a watchmaker’s magnifying glass. The optimum point of harvest occurs when a large number of the trichomes show amber colororation, while a few milky and even transparent trichomes are still present.
Influence of the harvest time in the psychoactivity of the different photoperiod-dependent and autoflowering cannabis varieties
|Type of Variety||Early harvest||Normal harvest||Late harvest|
|Indica||Relaxing but also energetic, allowing to perform activities.||Narcotic and relaxing, almost too much to be active.||Very narcotic, adequate for sleeping or as medicine.|
|Hybrid||Fun, without unexpected euphorias.||Good balance between relaxation and excitement. More active if the sativa genetic is dominant and more relaxing if they have more indica genetics.||Relaxing, but not as much as indicas.|
|Sativa||Euphoric, almost to the same extent as amphetamines.||Exciting and entertaining.||Psychoactive but a bit more meditative, sometimes almost lysergic.|
The effect descriptions are illustrative and approximate; cannabis psychoactivity is very complex, the strains are very diverse and each person is different from all the others, so the range of the effects may vary a lot.
Types of trichomes
Trichomes are very similar to hairs, covering the surface of plants. Some types of trichomes secrete substances (such as resin) and are called glandular trichomes or resin glands, versus non-glandular trichomes that do not secrete anything.
Marijuana resin glands are cells that secrete essentially terpenoid compounds. It is in these glands that THC is also synthetized. THC is the main psychoactive compound of cannabis, among many other cannabinoids (CBD, CBN, CBDA, etc.)
There are several types of glandular and two non-glandular trichomes that do not contain resin or cannabinoids.
- Bulbous glandular trichomes: Small trichomes without peduncle and with a small head of about 20μ.
- Glandular trichomes with peduncle and head: These are the main trichomes responsible for the psychoactivity of the plant. They are crowned by a large head that comes out of a peduncle (they have the shape of chupachups lollypops). The head presents a diameter of up to 100μ.
- Glandular sessile trichomes with head: They do not have peduncle, but a medium sized (40-60μ) head full of resin.
- Cystolytic hairs: Short hairs, swollen at the base. They contain calcium oxalate crystals. We find them on the surface and at the tips of leaves and bracts.
- Unicellular hairs: Long and narrow, they have no head and look like real hairs. They cover the entire surface of the plant.
Harvest tricks and techniques
Next we leave you a few recommendations and tricks for an ideal harvest.
- Flushing Cannabis Plants. Use only water during the last two weeks before the expected date of harvest (do not use fertilizers). This removes the remaining traces of nutrients from the soil, forcing the plant to consume the nutrients stored in its tissues. This will make the final taste of the buds much softer and more pleasant.
- Avoid harvesting plants while the soil is wet. It is advisable to let the soil dry before cutting the plants.
- If you have small plants, the best and easiest thing is to cut them at the base of the central stem and harvest them completely at once. However, in large plants it will be advisable to cut branch by branch, making it easier to manicure.
- In dense or large plants the top buds usually mature before the lower ones, so harvesting the top branches before may be a good idea, as you can then leave the lower part of the plants a couple of weeks longer until these flowers achieve maturity.