How to tell when your pot plant is ready for harvest

Make sure everything goes as planned.

Mar 31, 2018
How to tell when your pot plant is ready for harvest

Joaquin Fonseca, the president of a cannabis club and owner of a grow-shop harvests a cannabis plant in Montevideo, on December 10, 2014. (Photo by Nicolas Garcia/AFP/Getty Images)

You’ve spent months pampering what looks suspiciously like the most beautiful marijuana plant in history.

Your “burning” desire to smoke those yummy-looking buds is having a battle royal with your need to wait until the time of maximum potency. After coming this far, this is no time to screw up. When is the perfect time to harvest? Here’s how to tell.

Don’t become overdependent on estimated flowering times.

If you’ve ever bought seeds, you’ve probably seen general guidelines such as “indica: harvest after eight weeks of flowering” or “sativa: harvest after 10 weeks of flowering.” While broadly useful, these guidelines are not to be interpreted as strict timetables.

To know the best time to harvest cannabis, you’ll need to be more clever than that. You’ll need to use your powers of observation. But that’s not a bad thing, or some onerous task. In fact, it connects you to every cannabis farmer that has ever lived.

There are two main methods for determining bud ripeness.

You should ideally use both methods of determining bud ripeness when deciding when to harvest your pot plant.

1. The pistil method

giphy This doctor tried to convince Carl Sagan to stop smoking weed

The pistils are the long white hairs which sprout from marijuana flowers. They start out milky white in a young female plant. As the flowering period progresses, they start to turn color. More and more of the hairs turn orange, then dark red or brown.

When roughly three-quarters of the pistils have turned red and the calyxes from which they sprout have swelled, it’s time to harvest. (Just to keep you on your toes, different strains of cannabis do this on different schedules.)

Earlier harvests give the resulting buds a more “up,” stimulating effect. Harvesting at peak ripeness will yield the most potency. And harvesting when all the pistils are red or brown will produce the heaviest, sleepiest “narcotic” effect.

2. The trichome method

giphy This doctor tried to convince Carl Sagan to stop smoking weed

The second, and more exact, method for determining flower ripeness is through taking a look at the trichomes. You’ll need a loupe or some other magnifying glass for detailed viewing.

Trichomes are the tiny, stalk-like glands which sprout most heavily from the seed calyxes. The glands have a round ball of resin on top that’s the good stuff. (Trichomes also appear everywhere else, albeit in smaller numbers, on all the aboveground parts of the plant. But the flower trichomes are the ones we’re concerned with here.)

Trichomes are the resin glands of the cannabis plant. THC and all the other cannabinoids are produced here. Trichomes start out clear in young flowers, then turn milky or cloudy, and finally amber.

Many growers agree that when about half your trichomes have turned cloudy it is an ideal time to harvest. Waiting too long can reduce potency; amber trichomes can indicate cannabinoid degradation. Amber trichomes result in a sleepier, more lethargic high than milky or clear ones, according to most growers. This is because some of the THC has degraded to cannabinol, CBN.

Make sure you’re ready.

HarvestCannabis This doctor tried to convince Carl Sagan to stop smoking weed
Newly pruned cannabis plants sit in a wicker basket at the KannaSwiss GmbH greenhouse facility near Kerzers, Switzerland, on Thursday, Oct. 19, 2017. (Photo by Stefan Wermuth/Bloomberg via Getty Images)

Just because you’ve had months to prepare for your eventual harvest doesn’t mean you should relax. Beyond ensuring that the timing of your harvest is right, it’s important to be ready when the time comes.

Many growers feel it’s important to “flush” the plants for a couple weeks prior to harvest. This simply means using pure water rather than giving your plants any more fertilizer or plant food in the last two weeks.

Have a clear plan in mind before harvesting. If you’re in a non-secure situation in a prohibition state, you’ll need to think about transportation of the harvested plants from the grow site to where you’ll be drying and curing them.

While this may seem obvious, make doubly sure your drying/curing room is ready before you harvest any plants. That way, as soon as you harvest, you can hang the plants up to dry without any further stress.

Mar 31, 2018