Cannabis Sativa L.

Cannabis is a genus in the family Cannabaceae, a small family of flowering plants. Cannabis sativa L. is a species of Cannabis.

 The Cannabis Life Cycle
 
Depending on the taxonomic treatment adopted, Cannabis sativa L. can include up to three subspecies: Cannabis indica, Cannabis sativa, and Cannabis ruderalis.
 
  • Cannabis Sativa: Tall, long branches, large narrow leaves. Thought to originate from East Asia. Domesticated for stem fiber and/or oil seed in Western Asia and Europe. Naturally low tetrahydrocannabinol (THC) and high cannabidiol (CBD).

     

  • Cannabis Indica: Shorter, bushier, wider leaves. Domesticated in South Central Asia. High cannabinoids, mostly THC. Famous for producing dense, resinous buds, traditionally used for hashish production.

     

  • Cannabis Ruderalis: Very short and naturally produces very little THC. Has been bred to produce hybrids and “autoflowering” varieties with even shorter flowering times. Thought to originate from Eastern European where Cannabis sativa L. adapted to a shorter summers.
 
The majority of modern “strains” (more accurately chemovars, cultivars, or varieties) will be a hybrid of the three.
 
Cannabis sativa L. in the wild

 

Selecting Your Variety

Feminized vs. Regular Seeds: To reduce the likelihood of producing male plants, seeds may be “feminized”, meaning they were produced by female plants intentionally pollinated by another female plant induced to grow pollen sacs. Therefore, feminized seeds are more likely (~99%) to produce a female plant. Starting from regular seeds will result in both male and female plants, generally at equal rates.
 
Outdoor vs. Indoor: Most seeds purchased from seed banks will be used for the purpose of growing domesticated, indoor cannabis. While some cultivators prefer to grow outdoors, growing cannabis for personal use in Illinois must be done in an enclosed space or indoors. Purchasing seeds bred for indoor growing is recommended.
 
Flowering Time: Every cannabis variety will have its own unique set of characteristics, including different flowering times. Shorter flowering times are typically preferred to increase frequency of harvest and, therefore, overall yields. Flowering times are typically two months but can be longer. Consumers should be wary of seed banks underestimating flowering times to improve marketability.
 
Photoperiod vs. Autoflower: Naturally, the cannabis plant will complete its life cycle in one growing season, meaning it will begin flowering as the days get shorter. This natural cycle is referred to as “photoperiodism”. Photoperiod seeds will result in plants that must to be triggered to begin flowering. Alternatively, “autoflowers” are varieties specifically bred to have a nearly non-existent vegetative stage and will begin to pre-flower almost immediately after the seedling stage. Autoflowers are generally smaller plants as they have been bred with the Ruderalis subspecies.
 
Cannabinoid Ratio: A ratio is the amount of one cannabinoid relative to another, typically the ratio between THC and CBD. For example, a variety that contains 10% THCa and 10% CBDa would have a 1:1 ratio. A variety that contains 6% THCa and 12% CBDa would have a CBD to THC ratio of 2:1 or THC to CBD ratio of 1:2. Cannabis users with lower THC tolerances should seek these balanced varieties with more moderate effects.
 

Terpene Profile: Terpenoids or terpenes are the fragrance molecules that give cannabis its unique aroma and flavor. The combination of terpenes, cannabinoids, and other plant compounds may provide synergistic effects and potentially enhance medicinal value. This synergy is often referred to as the “entourage effect.” Distinct ratios of cannabinoids and terpenes provide a meaningful profile of the plant’s genetic identity and chemical composition but also provide a better understanding of expected effects.

 

Cannabis botany 101, covered of our cannabis growing workshops

 

Essential Nutrients

As a rule of thumb, nitrogen and potassium uptake are greatest during vegetative growth. Higher rates of potassium and phosphorus are needed during the flowering stage. Adequate feeding can be done with two main N-P-K blends for veg (5-2-1) and flowering (1-3-7).
 

Nitrogen (N): Most important during vegetative growth. Reduce nitrogen during flowering.

Phosphorus (P): Helps with root development and flower formation. Increase during flowering.

Potassium (K): Moves sugars from leaves to flowers and promotes cell hydration. Large requirement for K during flowering.

Calcium (Ca): Used most during vegetative stage. Increases pH.

Magnesium (Mg): Important throughout plant cycle but in lower amounts.

Sulfur (S): Important throughout plant cycle but in lower amounts. Lowers pH.

Micronutrients: Includes metals (iron, manganese, zinc, copper, nickel), chloride, molybdenum, and boron. Sources of micronutrients include dead plant tissues, compost, and manure.

 

Understanding training techniques, covered in our workshop series

Managing pH

If the pH of your growing medium is too low or too high some nutrients may be locked out, meaning the plant will not be able to absorb them. pH is a scale used to determine how acidic or basic (alkaline) a solution is.
 
If pH becomes too alkaline (above 7.5) or too acidic (below 5.5), it will inhibit nutrient uptake. Correct pH level (6.0-7.0) and consistency in pH level will allow the plant to better absorb nutrients.
 

Test the pH of your runoff water to check whether your soil is within acceptable range, too acidic, or too alkaline. Make sure to use pH corrected water when watering. Adjust with lemon juice or vinegar to decrease pH.

 


Measuring and managing pH covered in our workshop series

 

Growing in Soil vs. Hydroponics

For beginners, we recommend growing in soil (over hydroponics) for the following reasons:
 
  • Soil is more forgiving
  • Soil is less susceptible to pH swings
  • Well prepared soil will provide nutrients for the plant for a few weeks at a time without incessant feeding
  • Typically, with over-the-counter soils and soil-less mixes, there is enough plant nutrition for 4-6 weeks of growth
  • Hydroponics is susceptible to pH swings and requires constant monitoring- one mistake can ruin entire crop within a day
  • Hydroponic systems have a higher startup cost and larger learning curve

     


Germination through vegetative stage covered in day 2 of our workshop series

 

Growing in Soil

Healthy, strong, large root systems are the most important factor when it comes to growing. The larger the root system, the larger the plant and bigger the yields.
 
When planning the grow, use the largest possible pots, wider rather than taller if height is a issue. The bigger the pot, the bigger the plant will grow. The smaller the pot, the smaller the plant will be.
 
Most pre-mixed soils and soil-less mixes will come with enough nutrients to last about 4-6 weeks. Eventually, the plant will absorb all of the nutrients in the soil, which can be supplemented or amended with additional nutrients.

 

Trichome Inspection

Trichomes are a good guide for when to harvest the plant, but don’t all mature at the same time. Monitor and prepare to harvest when the majority of trichomes are either cloudy, amber, or a mix of both.
 
Inspection requires a hand held microscope/magnifying glass (30x minimum). It can be difficult to keep steady. It’s recommended to cut off a small part of flower and hold the microscope to the flower and check the trichomes.
 


Inspecting trichomes with students of Home Grow Chicago’s cannabis growing class

 


If trichomes appear as clear/opaque under the microscope the potency is still developing and not ready. The trichomes will transition to cloudy/milky and finally turn amber.

 

Learn to inspect trichomes at our cannabis growing class

 

Why Home Grow?

Besides experiencing the joy of consuming your own home grown cannabis and knowing exactly what goes into your plant, developing a community of growers and meeting new people can be one the best things about home growing.
 
Will your consumption costs be offset by home cultivation? The average person spends between $500-$2500 on cannabis every year, and one ounce of cannabis costs between $100-$450 at the dispensary, depending on your location. The average yield per plant may be between 2-4 ounces for most beginner but can reach upwards of a half pound if you procure high-quality genetics and give the plant proper care. Taking a start up cost of $600 and your utility bill into consideration, yielding one pound total (16 ounces) will save you at least $1,500.
 
Home cultivation does not come without challenges. Our cannabis growing workshops in Chicago are designed for first time growers and guide those new to indoor cultivation through the fundamentals of growing medicinal plants for personal use. If you are wondering where to begin, consider signing up for our workshops.