Seeds and Seedlings

Exponential growth of seed selection and legal seed sales in the Netherlands, the United Kingdom, Canada, France, Switzerland, Spain, medical cannabis states in the USA, and many other countries, is making cannabis genetics more accessible than ever before. Most of the seeds (genetics) are available worldwide via Internet purveyors. Cannabis seeds are sold in every country on earth—some of which are illegal. Google “buy marijuana seeds” for an eye-opening example.

Exponential growth of seed selection and legal seed sales in the Netherlands, the United Kingdom, Canada, France, Switzerland, Spain, medical cannabis states in the USA, and many other countries, is making cannabis genetics more accessible than ever before. Most of the seeds (genetics) are available worldwide via Internet purveyors. Cannabis seeds are sold in every country on earth—some of which are illegal. Google “buy marijuana seeds” for an eye-opening example. 

There are thousands of varieties of cannabis. Most popular varieties include a combination of two or more of the following: Cannabis sativa, Cannabis indica, and Cannabis ruderalis. There are fewer pure indica, sativa, or ruderalis seeds available. The majority of seeds are bred to grow best indoors. Often indoor varieties are easy to acclimate to greenhouse climates. Fewer tried-and-true varieties are available for outdoors, but their number continues to grow.

Cannabis seeds available today are one of four basic types:
1. Natural – produce separate male and female plants
Mother Nature’s original seeds
Natural or “regular” seeds require 11–12 hours of light and 11–12 hours of darkness daily to flower. See chapter 08, Flowering for more information on indica and sativa varieties.

2. Feminized – produce 99+ percent female plants. No male plants; male flowers occasionally occur.
Female-only plants were first developed in India in 1982.
*Feminized seeds require 12 hours of light and 12 hours of darkness daily to flower.All regular seeds can be feminized.
*Study by H. Y. Mohan Ram and R. Sett, Department of Botany, University of Delhi, Delhi (India) – “Induction of Fertile Male Flowers in Genetically Female Cannabis sativa, Plants by Silver Nitrate and Silver Thiosulphate Anionic Complex”

3. Autoflowering – ready for harvest 70–80 days after germination
Seeds contain C. ruderalis genes mixed with indica and/or sativa genes.Autoflowering seeds flower regardless of light regimen. Autoflowering feminized seeds have been very popular in Europe since 2008, with the introduction of ‘Lowryder II’ genetics. Before that they were considered a novelty.
New autoflowering varieties are growing 3–4 feet (91–122 cm) tall.
Super autoflowering varieties are growing 6–7 feet (183–213 cm) tall.

4. Autoflowering Feminized – produce 99+ percent female plants that flower and are ready for harvest 70–110 days after seed germination
Seeds contain C. ruderalis genes mixed with indica and sativa genes.
Autoflowering feminized varieties flower after 3–4 weeks of growth, regardless of light regimen.
Super autoflowering-feminized varieties flower after 4–5 weeks of growth. They grow longer and bigger.
F1 hybrid seeds have “hybrid vigor.” F1 hybrids grow faster and bigger than seeds of non-F1 hybrids.  See chapter 25, Breeding for more information on F1 hybrid plants

Seeds

A seed contains all the genetic characteristics of a plant. The genetic code contained within a plant dictates whether it is regular, feminized, autoflowering, or autoflowering feminized. Seeds are the result of sexual propagation and contain genes from each parent, male and female.* Some (intersex) plants, known as hermaphrodites, bear both male and female flowers on the same plant. The genes within a seed also dictate a plant’s size; disease- and pest resistance; root, stem, leaf, and flower production; cannabinoid levels; and many other traits. The genetic makeup of a seed is the single most important factor dictating how well a plant will grow under artificial light or natural sunlight and the levels of cannabinoids it will produce.

*See chapter 25, Breeding for deviations from this rule (i.e., where intersex plants are bred).

The genetic makeup of a seed is the single most important factor dictating how well a plant will grow under natural or artificial sunlight and the levels of cannabinoids it will produce.

All seeds have the same basic requirements for germination and seedling growth. Strong healthy parents, proper breeding practices, and excellent care will yield strong seeds that germinate well. Strong seeds produce healthy plants and heavy harvests. Seeds stored under adverse conditions (hot, cold, or humid) or stored too long will germinate slowly and have a high rate of failure. Vigorous seeds initiate growth within a day or two. Some seeds take longer to germinate. Seeds that take longer than a month to germinate could always be slow and less productive.

The cask, or outer protective shell, on some seeds never properly seals, which allows moisture and air to penetrate. It also causes hormone concentrations to dissipate and make seeds less viable. Permeable seeds invite diseases and pests to move in. Such seeds are immature, white, fragile, and crush easily with slight pressure between finger and thumb. These are weak seeds and do not have enough strength to germinate and grow well.

A simple view of a seed exposes an embryo containing genes and a supply of food wrapped in a protective outer coating. Seeds range in size from small dark ones from tropical climates to huge seeds bred for hemp oil extraction. Mature seeds that are hard, beige to dark brown, and spotted or mottled have the highest germination rate. Soft, pale, or green seeds are usually immature and should be avoided. Immature seeds germinate poorly and often produce sickly plants. Healthy, fresh, dry, mature seeds less than a year old sprout quickly and grow robust plants.