So, what is the best time to harvest?
There is more to harvesting cannabis plants than just cutting them down. Before harvesting, the plants should be fed plain water only with no fertilizer (nutrients). This is to remove any fertilizer that has built up in the plants themselves, and the hydroponic media or soil they were grown in. After the plants are harvested, they have to be manicured and dried.
Even with a small indoor or outdoor garden (less than 20 plants) it can take a few hours to harvest, manicure, and hang the buds for drying. A large garden (more than 50 plants) may take a full days work, or longer. The plants must be manicured and hung to dry right after they are cut down, and this can be time consuming.
Make sure you leave yourself a steady 6 hours of time to work, the first time you harvest a small garden. Make sure you leave yourself a full day to work, the first time you harvest a large garden. You can base the time it will take to harvest future crops based on the amount of time it takes to harvest your first crop.
If you have grown a particular cannabis strain before, you will have a good idea when it will be ready to harvest. If you are a first time grower or if haven’t grown a particular strain before, try to get your seeds from someone who can tell you not only what strain it is, but also the expected harvest time.
The reason why it is so important to know when the plants will be ready to harvest is because prior to harvest, you will need to remove the fertilizer contained in the plants. The plants themselves and the hydroponic media or soil the plants were grown in will store some of the nutrients that have been fed to them.
cannabis plants need fertilizer so they can grow, mature, and produce THC. In order to remove fertilizer from plants, you feed them water with no nutrients for one or more feedings just before they are harvested. Tap water will have some chemicals present, it is best to used distilled water or water treated with reverse osmosis for this purpose.
When you know the approximate time the plants will be ready to harvest, you will be able to wait right before you are going to harvest and give them water with no nutrients. In this way they are allowed to grow for the maximum amount of time (large harvest) before being flushed.
The plants will use up the fertilizer they have stored in them and growth will not slow down, if done properly. If nutrients are not flushed from the cannabis plants, the resulting cannabis will taste bad and may also be hard to ignite.
If you are growing hydroponic cannabis, start clearing about 7 days before harvest. This can be done by changing the solution and using only distilled water or water treated with reverse osmosis (no nutrients). Some growers will change the water two or more times before harvest because the media may still hold nutrients after the first flush.
With soil you need to change to distilled water or water treated with reverse osmosis about 14 days before harvest. Avoid slow release fertilizers because they are hard to remove. Soil growers that have to use slow release fertilizer should employ regular nutrients for the last month.
With hydroponics, if you know that the cannabis strain will be ready to harvest 10 weeks after flowering is started, switch to water only feeding about 9 weeks after flowering. With soil, if you know that the cannabis strain will be ready to harvest in the middle of september, switch to water only feeding at about the beginning of september.
When growing in soil, you can stop watering the plants 2 days prior to harvest. This is not essential but it will speed the drying process. Do not stop the flow of water to hydroponic plants. If you do, they will wilt and begin to die within a few minutes to a few hours.