Does a 3-Day Dark Period Before Harvest Increase THC? | Grow Weed Easy (2024)

FAQs

Does darkness before harvest do anything? ›

This technique can help to enhance trichome production and boost cannabinoid percentages. However, whether or not an extended dark period before harvest has the same effect is less certain. Another hypothesis states that cutting the lights panics plants into producing more nugs on each of their bud sites.

Give cannabis plants 24–48 hours of total darkness

By subjecting plants to 48 hours of total darkness right before harvest, some growers believe it stresses the plant into thinking it's missed its chance to flower as nights start becoming longer.

12 or more hours of darkness is the biological trigger for photoperiod cannabis to bloom. Outdoors, as the nights grow longer incrementally from the summer solstice onward, some strains can even begin flowering when receiving 14 hours of sunlight.

Enter the 3-day dark period.

Essentially, the idea is to “shock” your plant in the days leading up to harvest in hopes of increasing the potency of your buds. The most common tactic is to place your plants in total darkness for 3 days before harvest.

Stop Watering 1-3 Days Before Harvest – After flushing, in the final days of harvest, you can further stress your plants by stopping watering. You want to allow the plant to start to wilt just a small amount, because then the plant “thinks” it is dying and as a last-ditch effort, it will increase resin development.

In these cases the low temperature at the end of flowering has affected the plants, provoking a very notable color change and an increased trichome concentration on the buds.

In the last two weeks, the buds will mainly mature and grow no more in size. The white trichomes (small resin-secreting stalks/hairs) on the buds will now slowly turn brown.

The ideal drying room must be dark, as light can damage the THC in your buds. While it does not hurt to have a light source inside to check on the progress of your buds, you should keep it off most of the time, and block all other passages of light that can enter the room.

For higher yields indoor, you want your plants to grow wide rather than tall. You want a bushier plant so more buds have access to direct light, rather than a long, lanky plant with several buds hidden under a canopy. By transferring your plants to larger containers, you can encourage more outward expansion.

Flushing effectively allows your plants to absorb any nutrients that are still in the soil. By flushing your cannabis plants before harvest you can avoid a harsh and unsatisfying end-product. If cannabis plants are not properly flushed, the minerals and nutrients used during the cultivation process are still present.

How long before harvest should you stop nutrients? ›

ENDING NUTRIENT CYCLE / FLUSHING

To prevent harsh tastes and unsavoury chemicals making their way into your stash, you can simply stop feeding any nutrients in the last 1.5–2 weeks of flowering. If you are growing hydroponically, you shouldn't stop feeding until the last five days as they will be growing in water only.

Waiting longer to harvest gives the trichomes ample time to develop. But the longer you wait, the more highly intoxicating and sedative your flower will become. This is especially true for indica strains, but even sativa strains can become sedating.

Harvesting too early can cause you to lose some of the plant's potency, creating a different and potentially less pleasurable consumption experience. Waiting just a week can produce significantly better results.

Darkness Before Harvest

Many growers swear by this method as a way to boost trichomes in the last day or two before harvest. Giving cannabis plants complete darkness for 24-48 hours is said to increase the number of trichomes, as well as improve flavour.

What Time of Day to Harvest? Timing the harvest is Paramount to the final quality. Harvest your precious buds in the dark, just before the lights normally come on. If possible, do not allow the plants to see direct light as long as their roots are attached.

The yellowing of plant leaves is simply due to a nitrogen (N) shortage which is a perfectly natural phenomenon as the plants nears the end of its life cycle. You are in the eighth week of flower, so you are likely close to harvest time depending on your strain.

A bud hardener is an additive you can use at the end of the flower cycle to tighten up your flowers and pack on weight. They are typically used in the final 3 weeks or so of the grow cycle and contain a mix of macronutrients, micronutrients, minerals, essential oils, etc.

While technically you can start harvesting as soon as your plant produces flowers, the cannabinoid levels remain very low until the buds are mature. Avoid premature harvesting as much as possible, but if you really need to, it isn't the end of the world.

These airy flowers are often the result of suboptimal growing conditions, a lack of light, or nutrient deficiency. Fluffy buds don't only look less appetising, but you'll need to use more of your harvest every time you roll a blunt or hit a bowl.

As previously stated, moderate levels of nitrogen and phosphorus work best to sustain trichome growth to the maximum level. Dumping nutrients on your plant during the second half of the flowering cycle can result in reduced cannabinoid and terpene content, thereby lowering your bud quality in both flavor and potency.

How do you make your buds bigger? ›

Increasing the amount of CO₂ in your grow room can help you grow bigger, denser buds. By doing so, you'll help plants photosynthesise faster and encourage them to take up more nutrients and water.

Late flowering / Ripening stage – week 6 to harvest

They are sticky to the touch and can be very smelly. You are very close to reaching your goal = harvesting! Most importantly, buds are now covered in trichomes, which are rich glandules for secreting THC and other cannabinoids.

Week 3. Your cannabis plants have still not entirely stopped growing and will now be about 50% bigger than what they were just three weeks earlier. Although still stretching a bit, the stretch will now gradually slow down and soon come to a complete halt.

Timing the harvest is Paramount to the final quality. Harvest your precious buds in the dark, just before the lights normally come on. If possible, do not allow the plants to see direct light as long as their roots are attached. Direct light on a plant will draw up stored starches and sugars from the root system.

You see, during the growing cycle, your plants store excess amounts of nutrients, salts and other compounds. If you don't allow the plants a chance to dispose of these surplus compounds by flushing them before harvest, your final product will be much harsher and more bitter tasting.

We recommend washing 100% of your cannabis harvest. The cannabinoids in your buds are fat-soluble; a gentle wash does not disturb the potency of your product and will prevent you from combusting and inhaling dirt, hair, and dust, leading to a far cleaner smoke than you're used to.

Plants, however, do not stop growing when they are being flushed. Rapidly expanding buds can be seen even while the flush is removing nutrients.

Light intensity

To some degree, more light translates to fatter buds and higher yields (you'll need to pay attention to the distance between your grow light and plants or your plant may suffer from light burn). Increasing light intensity is the most effective way to fatten up buds.

Usually, growers trim the fan leaves weeks before harvest, which is a period that leads to senescence, a phase in the plant cycle when the larger leaves start fading away. It is safe to start removing these dying leaves and continue until harvest. However, the main trimming processes commence after harvest.

Can you speed up the flowering stage? ›

If plants have a short-day response, then shortening the days by totally excluding light from the plants for 12 hours per day will accelerate flowering.

How fast do trichomes change color? This variable largely depends on the strain. Some transitions occur within 5 days of flowering, while others take up to 2 weeks. Make sure to check your trichomes every day.

Dry trimming typically means better quality marijuana in the end, as retaining the moisture while drying allows the buds to dry at the correct speed. This can preserve potency and terpenes. Dry-trimmed cannabis provides a smoother, more pleasant smoke.

While not mandatory, it's definitely a good idea to wash cannabis flower buds that were grown outside. The process reduces outdoor air pollutants that may have accumulated on the buds such as dirt, dust, pollen, toxic wildfire ash, caterpillar poop, insects, bird debris, and other particulate matter.