Understanding the trichome development timeline is key to producing high-quality, intentionally balanced experiences for the cannabis consumer. Trichomes are the resin glands or sticky outgrowths on the surface of buds, stems, stalks, and leaves of a cannabis plant. The Greek root of the word trichome translates to “growth of hair,” which appropriately describes their fuzzy, hair-like appearance. They function as part of the plant’s natural defense system but are prized for producing and storing aromatic terpenes and cannabinoids such as tetrahydrocannabinol (THC) and cannabidiol (CBD) that are largely responsible for the smell and effects of cannabis. At each trichome stage, the plant will contain different ratios of cannabinoids like CBD and THC, which is why trichomes are one of the most reliable ways to identify when a plant is ready to be harvested and further processed with commercial trichome extraction equipment. Because growing cannabis is an extremely delicate process, it is vital to carefully observe trichome development during a plant’s flowering process. By observing the color and opacity of trichomes, growers can often determine the best time to harvest for designated types of consumer experiences. However, it can be very difficult to identify when a trichome is cloudy versus clear. There are numerous stages trichomes go through and first-time growers will benefit from referencing an experienced growers’ trichome color charts and harvest charts. Trichomes can be as small as 10 micrometers and as large as 500 micrometers. Because of their minuscule size, trichomes are best observed through a device that can magnify between 30 and 120 times. Under the microscope, trichomes appear like tiny hairs on the surface of the cannabis plant. Growers should focus on the trichomes that resemble the shape of a mushroom, as these are the trichomes that contain the majority of psychoactive and medicinal compounds that make cannabis such a unique and desierable plant. This type of inspection will help the grower to accurately gauge the trichome stage a plant is in and whether it is ready to harvest.
How to Examine Trichomes
| Capitate-Stalked Trichomes that are mostly cloudy or milky in color. |
3 Different Types of Trichomes on Cannabis
There are three types of glandular trichomes relevant to the maturity and chemical balance of cannabis plants. Understanding the nuances of trichome types is essential to successful harvests. The three types of trichomes that growers should focus on are bulbous trichomes, capitate trichomes, and capitate-stalked trichomes.
Bulbous Trichomes
Bulbous trichomes are minuscule bulbs that are evenly distributed across the entire surface of the plant and contain very little THC. They are only 10 to 30 micrometers in size, so they must be identified with a microscope. These trichomes create the crystal-like sheen and stickiness for which high-grade cannabis is known.
Bulbous trichomes can be identified by their one-cell stalks and gland heads that swell with plant oil. Some research suggests bulbous trichomes exist to alert plants of insect intruders and protect the plants from sunburn. Many cultivators use bulbous trichomes as an early indicator for harvesting.
Capitate Sessile Trichomes
These trichomes are more abundant and slightly larger than bulbous trichomes, measuring between 25 and 100 micrometers. Capitate sessile trichomes are typically only visible with a microscope. They can be identified by their mushroom-shaped structure attached to the plant without a stalk and are often located on the underside of sugar leaves and fan leaves.
These trichomes produce cannabinoids throughout the lifecycle of a cannabis plant, but at much lower levels than capitate-stalked trichomes. These trichomes are thought to be most suitable for edible cannabis products and cannabis-infused liquids. In fact, many cultivators and processors set out to turn their trichomes into profits by separating this variety for edibles.
Capitate-Stalked Trichomes
The largest and most abundant of the three trichome types, capitate-stalked trichomes are also shaped like mushrooms and are characterized by their large bulbs at the head of the stock. These trichomes can be seen with the naked human eye and are found on the surface of female cannabis plants far more than their male counterparts.
Capitate-stalked trichomes are rarely seen on sugar leaves, fan leaves, or stems and can be up to 500 micrometers in size. As the flowering stage of a cannabis plant progresses, capitate-stalked trichomes dramatically increase in density. Interpreting the maturity of these trichomes is crucial because they produce the highest quantity of desirable cannabinoids and terpenes.
| Examples of clear, milky, amber, and mixed trichomes. |
4 Stages of Trichome Development
Trichome formation and maturation change the potency and THC/CBD balance of a cannabis plant. There are four stages of trichome development to which growers must be privy in order to produce cannabis products used specifically in the medical marijuana industry as well as the recreational industry. During each stage, the trichomes change color, which is why a trichome chart is an essential point of reference for new growers. Throughout their development, trichomes appear clear, milky, amber, and mixed in color.
Because new flowers can grow on top of each other, flower clusters near a single plant can develop at different stages of trichome development. Choosing to harvest only the top of a plant can help growers get the most out of their harvest. Cannabis strains such as California Gold, Space Cookies, and Nebula are known for their brilliant trichome development.
Clear Trichomes
Clear trichomes are the first to appear on the cannabis plant during its transition from the vegetative state into the first week of the flowering process. Under magnification, the trichomes will appear either clear or opaque. During this stage, the plant is still forming THC and is not yet ready for harvest.
Harvesting buds too early in trichome development will produce a faint and potentially uncomfortable consumer experience. However, the appearance of clear trichomes throughout the lifecycle of a cannabis plant is a sign of healthy growth because cannabis plants are always forming new trichomes and producing more chemical compounds.
Milky Trichomes
When a trichome begins to appear cloudy, the THC levels are beginning to reach their ideal potency and flavor. At this stage, the plant is not fully matured; buds will appear small and lack the rich aroma consumers expect. When cloudy trichomes are covering the plant, THC levels are much higher than CBD levels, which means the psychoactive effects of cannabis are most prevalent.
If harvested during this stage, many cultivars will produce a more uplifting experience. Trichomes remain milky for about two weeks during the lifecycle of a cannabis plant. Growers may choose to harvest the buds at this time if they plan to pair the strain with CBD oil.
Amber Trichomes
Trichomes will begin turning amber in conjunction with milky trichomes. A plant that is covered primarily in amber trichomes will have higher levels of CBD, as much of the THC in the plant will have naturally converted to cannabinol (CBN). Growers can determine this stage by observing the lack of little white hairs on the bud.
During this stage, the hairs will appear a dark orange or brown color. This often reduces the psychoactive effects of cannabis consumption and creates a much more relaxing and sleep-inducing experience for the consumer. The medical marijuana industry often leans toward cannabis harvested at this stage because of its ability to manage pain and treat insomnia. Many Indica-dominant strains require growers to harvest the buds when at least 60 percent of the trichomes have turned amber.
Mixed Trichomes
For most cannabis harvests, growers look for a certain ratio of cloudy trichomes to amber trichomes. Many expert growers believe that the best time to harvest a plant is when the trichomes are 70 percent cloudy and 30 percent amber. Buds harvested with this ratio of trichome colors are frequently processed in the retail industry to create stimulating and cerebral effects for the recreational consumer.
Cultivating impressive trichomes is an essential part of a successful harvest, but those trichomes must be protected during processing. Due to the trichome’s delicate nature, their preservation requires delicate handling with a dry-sift, solvent-free trichome extractor that can operate as a stand-alone machine or with the addition of pulverized dry ice — using ‘180 Micron’ screens to provide the highest yield and quality possible to benefit businesses and customers alike.
