Optimizing the trichome yield in your cannabis crop is a matter of proper plant care and that means proper growing conditions. A few simple changes in your greenhouse will make all the difference in your production of buds and trichomes.
These conditions include proper lighting, humidity, and temperature to produce slight stress on the plants. Furthermore, some cultivation techniques such as super cropping can also be employed to induce plant stress and boost trichome production.
Finally, choosing a good strain as a foundation and knowing the right time to harvest are two fundamental elements of good cannabis cultivation.
What are Trichomes?
Trichomes are hair-like outgrowths that form the indumentum or pubescent covering of the plant. In cannabis, trichomes produce an iridescent, sparkling, or frosty surface.
Trichomes, apart from their esthetic appeal on buds, also are a source of THC (Δ-9-tetrahydrocannabinol) and other cannabinoids. They are a reflection of plant health.
The more trichomes a plant displays, the more potent the production of essential oils in the plant tissues. By judging the trichome presentations and development, growers can assess when plants reach their peak potency and are optimal for harvest.
Trichomes and their associated crystals do not require curing (as do the green parts of the plant) and can be harvested for use as is by using scissors, a screen, or by sloughing off using dry ice. They are the primary source for producing hashish (also known as kief).
Optimizing your trichome harvest starts with a good foundation and that means proper selection of a strong cannabis strain. Two good strains for starting out are White Widow and Limon Shining Silver Haze.
The names of the strains are derived from the appearance of a carpet of white trichomes that typically appear during flowering. White Widow is a 60% C. sativa hybrid and Limon Shining Silver Haze is a 75% C. sativa hybrid.
Get Some Basic Equipment
Make your life easier by purchasing some basic equipment to help you with tending your crop. The items you need include: some means of viewing the trichomes (10x loupe, smartphone with microscope attachment, or a hand-held digital microscope), outdoor thermometer, and a means of measuring relative humidity (humidity meter, sling psychrometer).
Standard grow lamps work just fine, but some growers claim that full-spectrum LED bulbs produce the right amount of light and apply some stress to the plants that help to boost growth Yes, stress! (See below).
Boosting UV-B (290-320 nm) exposure for the final 2-3 weeks before trichome harvest can increase yield, since trichomes are also thought to shield buds from excess UV light. Metal halide lights are a common source of UV-B production and can be purchased at your local hardware store.
An alternative to metal halide lamps is reptile lamps that are found at pet stores, although their light intensity is markedly lower than metal halide.
Humidity and Temperature
Controlling humidity and temperature for optimal growth and trichome development is not a matter of producing the perfect conditions to make the plant happy. The best conditions for trichome farming are actually slightly off optimal, producing some light stress in the plant.
Attempt to maintain humidity at or below 30%. This can be accomplished by use of a dehumidifier that can be purchased at any local hardware or home store.
Never drop the humidity to a point where the plant starts to wither or lose color.
Optimal temperatures for trichome production range from 21°-27°C (70°-80°F). Temperatures should never exceed 27°C to produce the best outcome.
Maintaining temperature is a simple matter of either growing plants in a cool area or, for better control, using a standard room air conditioner. This latter option also has the added benefit of dehumidifying the air to produce dry, cool conditions.
A gentle amount of stress when applied will cause plants to grow vigorously. In the natural world, environmental conditions are never constant and rarely ideal, so plants typically respond to changing conditions actively and will aggressively gather soil nutrients and shunt growth activity to the development of reproductive structures.
Maintaining low humidity, cooler temperatures (within the ranges above), and application of LED lighting collectively produce the right amount of stress to cannabis plants to foster growth and bud development. Another, more advanced technique that is proven, but takes practice to master, is super cropping.
Super cropping should be performed during the vigorous vegetative growth stage prior to full flowering or there is a risk of stunting development. Despite the name, it has nothing to do with “cropping” but with applying gentle torsional stress to plants.
Select an older part of the plant that is still pliable and green. Compress the stem between your fingers to crush the inner tissues without breaking the skin of the stem.
This will produce a softened area that will serve as a joint. Then, simply bend the stem over (60°-90°) and secure with either plant twist ties or zip ties.
If you happen to make a mistake and damage the skin, you can remedy the situation with an application of duct tape. The duct tape bandage should remain on the plant for about a week or so until the stem has scarred to a protective knot.
Choosing The Best Harvest Window
Making the most of trichomes is also about knowing when is the optimal time to harvest them. There are essentially four stages of development, which can be judged easily by eye.
Stage 1 (not quite ready): The trichomes appear to be thin and translucent. In this phase, trichomes and buds have not produced many cannabinoids.
Stage 2 (harvest window, early): Trichomes produce mushroom-like heads at their tips and appear to be much wider in diameter than in stage 1. They also start to become white and opaque, which correlates with the production of THC.
Stage 3: (harvest window, late): Trichomes began to yellow or will take on amber tones. This is reflective of the process of conversion of some THC to various cannabinoids.
Stage 4 (past peak): Trichomes in this state are fully amber in color and will begin to diminish in size and slough off the bud. This condition also reflects a loss of THC and cannabinoid potency.