Whether it's mid-October in Mendocino or week 9 of flower in your indoor hoop garden, there's always a point at which you ask yourself, “Are these girls ready for harvest?” Whether you are a master cannabis cultivator or a first-time hobby grower, there’s always some uncertainty when it comes to the best time to chop.
Harvest too early, your plants won’t reach their fullest potential. Wait too long, their THC content can break down and degrade into CBN, and your plants will lose flavor and potency. That’s because they’ve been exposed to too many UV rays along the way. You’ll also be subjecting your plants to additional environmental risks, like mold.
Although individual growers have different styles and preferences, most growers follow this philosophy:
Pay close attention to flower hairs and resin heads
The state of a cannabis plant’s flower hairs (stigma) and resin heads (trichomes) are the biggest determining factors for when it’s time to harvest. The hairs of the cannabis flower, called the stigma, are the female part of the flower. The stigma has a sticky bulb in its center, where pollen lands and the fertilization process first began. The trichomes are the plant’s production sites for cannabinoids and terpenes.
Generally speaking, a plant’s hairs through the first 4-5 weeks of its flowering cycle will be predominantly white, although some cannabis strains and certain plants will have white hairs with bright pink centers. After about 5 weeks of flowering, depending on the cannabis strain, climate and other factors, the flower hairs will start to darken. Some hairs will turn yellow, orange or even bright red. In most cases, if 50% to 80% of the hairs throughout a plant are a darker color, it’s probably time to harvest. The top of each plant is likely to receive more light than the bottom, so the top flowers generally reach maturity faster, and you may need to harvest a plant when some of its flowers aren’t fully mature.
The second major factor to consider is the plant’s resin heads. To look at the resin heads, you’ll need a handheld microscope. Early or premature cannabis flowers will have entirely clear resin heads. As a plant approaches full maturity, its resin heads will become milky and even slightly amber. As a general rule, if 60% of a plant’s resin heads are milky AND 50% to 80% of the flower hairs throughout the plant are a darker color, you can confidently harvest the plant.
Avoid satellite-ing during harvest time
"Satellite-ing" or "darting" will be a familiar experience to many seasoned cannabis growers, and it’s known by many different names. Satellite-ing is caused by over watering plants that are ready to be harvested. Over watering will cause the bracts or leaves that make up the flowers to protrude from the flowers and point out, resulting in overly mature, less dense flowers. This condition can make drying, curing and manicuring the flowers more difficult for you.
By keeping the color of the flower hairs, the clarity of resin heads, and the right amount of plant watering top of mind as harvest season nears, you can proceed with confidence that you’ll produce the highest yield.