Seeds & seedlings – Chapter 5

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. See “Finding Seeds” for more information.

Cannabis seed varieties developed in California are often crossed by European breeders and sold to gardeners around the world.

This Cannabis sativa plant grown in 1976 originated in Colombia. (MF)

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.

This ‘Afghani’ from 1979 is classified as Cannabis indica. (MF)

Regular cannabis plants are NOT feminized. Regular or naturally occurring cannabis plants are dioecious, having male plants and female plants.

Feminized ‘Power Plant’.

Cannabis seeds available today are of 4 basic types: 

1. Natural produce separate male and female plants Mother Nature’s original seeds Natural or “regular” seeds require 11 to 12 hours of light and 11–12 hours of darkness daily to flower. See chapter 8, 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 devel oped 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”

Cannabis ruderalis from the Joint Doctor

 Autoflowering feminized ‘Diesel’ × ‘Lowryder’

This beautiful roomful of F1 hybrid ‘Bubblicious’ plants is from Resin Seeds.

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’ ge netics. Before that they were consid ered a novelty. New autoflowering varieties are grow ing 3 to 4 feet (91–122 cm) tall. Super-autoflowering varieties are growing 6 to 7 feet (183–213 cm) tall.

4. Autoflowering Feminized – produce 99+ percent female plants that fl ower and are ready for harvest 70 to 110 days after seed germination. Seeds contain C. ruderalis genes mixed with indica and sativa genes. Autoflowering feminized varieties fl ower after 3 to 4 weeks of growth, regardless of light regimen. Super-autoflowering feminized varieties fl ower after 4 to 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.

Ruderalis cross

This seed contains the complete instructions (genetic codes) to grow a ‘Jack Herer’ plant. (MF)

Seeds & seedlings

The cutaway drawing in the center shows how the seed will develop into different plant parts.


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 fl ower 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 the above rule (i.e., in relation to intersex plants).

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 might always be slow and less productive.

The cask, or protective outer 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 white, immature, fragile, and crush easily with slight pressure between fi nger and thumb. These are weak seeds that 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.

regular seedsF1 hybrid vigornot F1 hybrids – less vigor
no diseasesslow to start
easy transportmoisture/heat-sensitive
smalleasy to lose
genetic expressionmust cull males
feminized seedsF1 hybrid vigornot F1 hybrids – less vigor
all femalepossible intersex qualities
use less spaceexpensive
use less light
autoflowering seedsF1 hybrid vigornot F1 hybrids – less vigor
flower in 70+ dayscould produce poorly
flower in summermust remove males
difficult to clone effectively
autoflowering feminized seedsF1 hybrid vigornot F1 hybrids – less vigor
flower in 70+ daysmay produce poorly
flower in summerdifficult to reproduce seeds
99+% femaledifficult to clone effectively

See chapter 25, Breeding, “Advantages/ Disadvantages” between seeds and clones. 

Seedlings are less work to grow out­doors because branches are usually farther apart at first. Clones grow too densely from the bottom and require more pruning work.

Ten seeds from a reputable seed company germinate into about half female and half male* plants. Some plants will be small, and others will be strong, healthy, cannabinoid-potent females. Of these “super” females, one will be more robust and cannabinoid-potent than her sib­lings. This super female is selected to be the mother of future “super” clones.

*Scientific studies show a minimal weighting of averages that favor one sex or the other. This could be based on various factors including the external to the gene set and a phenotypic control of gene expression.

Normally all the seeds are germinated and planted. Males and weak plants are culled. The best female, or a clone of the female, is often retained as a mother plant. The mother can’t be chosen until harvest. Two scenarios are possible: re-vegetation or taking cuttings from desirable females before they flower. This way, the plants grown out are big by the time the desirable female and correspond­ing clones are chosen for mother plants.

Seed Germination

Cannabis seeds need only water, heat, and air to break dormancy and germi­nate; they do not need extra hormones, fertilizers, or additives. Seeds sprout without light in a range of temperatures. Strong, viable, properly nurtured seeds germinate in 2 to 7 days. At germination, the outside protective shell of the seed splits, and a tiny, white sprout (radicle) pops out. This sprout is the root, or tap­root. Cotyledon, or seed, leaves emerge on a stem from within the shell as they push upward in search of light.

Break dormancy: Put newly harvested seeds in the refrigerator for a week or two to simulate winter. Remove and germinate. Seeds will germinate more uniformly because they all come out of dormancy at the same time.

The outer shell of ‘Skunk #1’ seeds breaks away when germinating.

Strong, healthy seeds germinate quickly.

Timeline for germinating most seeds:

At 36 to 96 hours Water is absorbed, root tip (radicle) pops through outer shell and is visible. 

At 10 to 14 days First roots and root hairs become visible.

At 21 to 30 days At least half of seeds are rooted by day 21. Seeds not rooted by day 30 will probably grow slowly.

Once seeds are rooted, cell growth accelerates; stem, foliage, and roots develop quickly. Seedlings develop into full vegetative growth within 4 to 6 weeks of germination.

Seeds are prompted to germinate by: 

air (oxygen)

Plant 10
Regular Seeds:
50% male
50% female
25% weak
25% strong
10% = 1 strong “best” possibly “super” female mother
Plant 10
Feminized Seeds:
99+% female
50% weak
50% strong
25% “best” with 1 “super” female mother
Plant 10 Autoflowering Seeds:50% male
50% female
25% weak
25% strong
5 female plants at harvest, no mothers
Plant 10
Autoflowering Feminized Seeds:
99%+ female
50% or less weak
50% or more strong
10 female plants at harvest,
no mothers


Once seeds are rooted, cell growth accelerates; stem, foliage, and roots develop quickly. Seedlings develop into full vegetative growth within 4 to 6 weeks of germination.

Soaking seeds in water allows moisture to penetrate the protective seed shell within minutes. Once inside, moisture continues to wick in to activate the dormant hormones. In a few days, hormones activate and send enough signals to produce an initial root tip. The white radicle (rootlet) emerges to bring a new plant into the world. Once a seed is moist, it must receive a constant flow of moisture to transport nutrients, hormones, and water so that it can carry on life processes. Some seeds need lots of moisture to wash out the dormancy hormones in the seed coat, and if they do not get enough moisture, they do not germinate. Conversely, too much water deprives the seed of oxygen, reducing its quality or destroying it. If fragile germinated seeds are allowed to suffer moisture stress now, seedling growth will be stunted. Soaking most seeds in water for 12 to 24 hours is all they need to initiate germination.

All the nourishment for a seed’s initial growth requirement is pulled from the fleshy cotyledons, or seed leaves.

Water seedlings with low-EC (electrical conductivity) household tap water during the first week or two of life. Supplemental nutrients are unnecessary and if applied in excess can disrupt internal seed chemistry. Some gardeners prefer to germinate seeds using distilled or purified water that contains virtually no dissolved solids. 

Seeds need oxygen from the air to germinate. Growing mediums that are too moist (soggy) will cut off oxygen supplies and the seeds will literally drown. Cannabis seeds germinate best when moisture is between 60 and 70 percent.


Overall, cannabis seeds germinate in temperatures from 70°F–90°F (21°C–32°C) and grow best at 78°F (26°C). Temperatures below 70°F (21°C) and above 90°F (32°C) impair germination. Low temperatures delay germination. High temperatures upset seed chemistry causing poor germination. Seeds germinate best under the native conditions and temperature ranges where they were grown.

Air & Oxygen

Sow seeds twice as deep as the width of the seed. For example, 0.125-inch (3 mm) seeds should be planted 0.25 inches (6 mm) deep. Adequate oxygen is unavailable for seeds planted too deeply, and tender seedlings have insufficient stored energy to drive through deep layers of soil or crusty hard soil when sprouting.

Agricultural Astrology — Planting by the Moon

Ancient Babylonians and Egyptians planted and harvested based on moon phases in relation to geographic location. The premise is that plants grow better when planted during the appropriate moon phase.

Moon phases cause ocean tides to rise and fall. They also affect the rise and fall of moisture in soil and fluids inside plants. The moon phase influence is said to be the same indoors, outdoors, and in greenhouse-grown cannabis. 

Cannabis gardeners who plant by the moon report faster-sprouting seeds that grow into vigorous plants. However, scientific evidence is lacking in regard to cannabis and other plants’ relationship with agricultural astrology.

How to Germinate Seeds: Step-by-Step

Step One: Soak seeds overnight in a glass of plain water. They may float on the surface at first but should sink to the bottom in a few minutes. Make sure seeds get good and wet so that water penetrates the outer shell and growth is activated. Do not let seeds soak for more than 24 hours, or they might get too wet, suffer oxygen deprivation, and subsequently rot.

Step Two: Remove seeds from glass of water. Pour water out onto two paper (or cloth) towels on a dinner plate. Fold the towels over the seeds to cover them.

Step Three: Drain the water from the dinner plate by tipping it to the side.

Step Four: Place the seeds in a warm location (70°F–80°F [21°C–27°C]), making sure they are in darkness. Some gardeners go so far as to set the plate in a vertical position (so taproot grows downward). The seeds can also be set on a grate for drainage and air circulation.

Germinate Hard-Shelled Seeds

Some seeds have a very hard outer shell (testa) and are difficult to germinate. Such hard cases can be softened or scarified to allow water to penetrate.

To scarify, line a matchbox with a piece of fine-grain sandpaper or emery board. Put the seeds in the matchbox and shake for 10 to 15 seconds. Remove the seeds and make sure they have been scuffed a bit. Just a little scuffing will allow water to enter and set germination in motion

Some gardeners soak their seeds in a 5 to 10 percent bleach solution to help dissolve the outer shell of the seed and speed germination. This practice can be overdone and is not necessary.

Set seeds in a matchbox with an emery board or sandpaper on the bottom.

Close seeds inside the matchbox.

Shake matchbox for 10 to 15 seconds to scarify the seeds.

Step Five: Check moisture level of towels several times a day, watering once or twice to keep them evenly moist. DO NOT LET THE TOWELS DRY OUT!

Let excess water drain away freely. The paper or cloth towels will retain enough moisture to germinate the seeds in a few days. Each seed contains an adequate food supply for germination. Prevent fungal attacks by watering with a mild 2 percent bleach or organic fungicide solution.

Step Six: In a few days, seeds will sprout. Once seeds have sprouted and each seed’s white rootlet is visible, use tweezers to carefully pick up the fragile, germinated seeds and plant them. Do not wait for the white rootlets to grow more than 0.25 inches (1 cm) before planting, or growth could slow. Plant each germinated seed with the white root tip pointing downward. Take care not to expose the tender rootlet to pro­longed light and air. Cover germinated seeds with 0.25 to 0.5 inches (1–2 cm) of fine, moist planting medium. See “How to Plant Seeds: Step-by-Step.”

Note: Overwatering and underwatering are the biggest obstacles most gardeners face when germinating seeds and grow­ing seedlings. Keep the soil uniformly moist but not waterlogged. Do not let the growing medium’s surface dry for long. Setting root cubes or planting flats on a grate allows good drainage. A shallow flat or planter with a heat pad underneath may require daily watering, while a deep, 1-gallon (3.8 L) pot will need watering every 3 days or more. A properly watered flat of rockwool cubes needs water every 3 to 5 days when sprouting seeds. When the growing me­dium’s surface is dry (0.25 inches [1cm] deep), it is time to water. Remember, there are few roots to absorb the water early in life, and they are very delicate.

Soak seeds in water overnight to speed germination.

Keep seeds moist after soaking in water.

Remove excess water from plate.

Germinate Old or Stressed Seeds

Old seeds or seeds that have suffered temperature, humidity, or light stress (or all three) are less viable and may not germinate. Increase germination rates by using MS (Murashige and Skoog) media used for tissue culture, available via a few Internet-based retailers.

Once planted, germinating seeds can also be placed a few feet below an HID lamp to add dry heat while they are pushing up through the soil. The heat dries the substrate, which requires more frequent watering. In cold rooms, place a heat pad or soil heating cables below growing medium to speed germination. Cannabis seeds germinate and sprout quickest when the soil temperature is from 78°F–80°F (25°C–27.5°C) and the air temperature is 72°F–74°F (22°C–23°C). Stems will stretch between internodes if temperatures exceed 85°F (29°C) for long.

Las radículas de estas semillas germinadas de ‘Skunk #1’ tThe rootlet on these germinated ‘Skunk #1’ seeds is the perfect length to transplant. At this point, fuzzy little root hairs have not yet developed. (MF)

Rootlets on many of these sprouted ‘Skunk #1’ seeds are becoming too long for optimal planting. Once a rootlet gets a bit longer, small fuzzy root hairs start to grow, and planting disrupts their continued growth. (MF)

How to Plant Seeds: Step-by-Step

Step One: Prepare fine soil planting medium, fine soilless mix, rockwool cube, Jiffy cube, etc., to receive seeds. Make sure all supplies are ready to go.

Pre-drill planting holes in medium after saturating with water.

Step Two: When seeds have sprouted and the white sprout is visible, carefully pick up the fragile sprouts (with twee­zers). Plant each seed in a pre-drilled hole in the growing medium or rooting cube, with the white root tip point­ing down. Take care not to expose the tender rootlet to prolonged intense light or air. 

Step Three: Cover the germinated seed with 0.25 inches (1 cm) of moist growing medium. Keep the medium evenly moist. Once the taproot sprouts, small fuzzy feeder roots will appear in 10 to 14 days.

Once a seed receives moisture, it must remain constantly moist. Moisture stress now will stunt or stop seedling growth. Dried or burned rootlet tips are the indi­cator of a good thing gone awry.

Soggy growing mediums cut oxygen supplies and cause seeds to drown. Planting seeds too deeply causes poor germination. Plant seeds twice as deep as the width of the seed.

Jiffy pellets expand when water is added. They make excellent pop-up pots to grow seedlings. They are also very easy to transplant.

This germinated seed was allowed to dry out for a little more than an hour. Notice how the tip of the root has shriveled. This small over­sight caused the resulting plant to have a very slow start in life.

Carefully set a germinated seed into a pre­made hole in growing medium.

Press growing medium over planted seed to ensure complete contact.

Grow More Females from “Regular” Seed

Environmental factors that influence sex determination of cannabis take effect the moment seedlings have 3 pairs of true leaves (not counting cotyledons).* These factors include but are not limited to the following:

1. Increase the level of nitrogen to make more female plants. Lower the nitro­gen level to create more male plants.

2. Increase the level of potassium to increase male tendencies. Lower the potassium level to encourage more female plants.

3. A higher nitrogen level and a lower potassium level for the first 2 weeks increases females.

4. Low temperatures increase the num­ber of female plants. Warm tempera­tures make more male plants. 

5. High humidity increases the num­ber of female plants. Low humidity increases male plants.

6. Low moisture in the growing medium increases males.

7. More blue light increases the num­ber of female plants. More red light increases male tendencies.

8. Fewer hours of daylight (e.g., 14 hours) increases the number of females. Longer days (e.g., 18 hours) make more male plants.

9. Stress: Any environmental stress tends to yield more male plants when growing from seed.

*Henk, owner of Dutch Passion Seeds,, was kind enough to allow us to adapt this information about environmental factors from his archives.

This germinated seed has pushed above the soil and started to grow toward the light.

If planting in rockwool, make sure seed rootlet is at least 0.25 inches (1 cm) long. Newly germinated seeds can push or “heave” out of rockwool. The root pushes the seed out. This is why it is best to germinate seeds before putting them into the rockwool substrate.

Color-coded labels make initial plant identification much easier.

How to Help Ensure Female Seedlings

Ethylene diluted in water and sprayed on cannabis plants increases the number of female flowers and decreases the num­ber of male flowers. To have the fullest effect, the hormone must be applied before pre-flowers appear. At this point plants are in the process of designating their sex, male or female.

Ripening fruit (especially bananas) releases a lot of ethylene. Several bunches of bananas can be set in a small, enclosed garden room containing the plants.

Large quantities of ethylene can be generated through the use of a catalytic generator, available from

The spray releases a gaseous vapor of ethylene. Ethylene gas surrounds and overwhelms plants with the female hormone, promoting female tendencies. When enveloped in female hormone, cannabis plants designate sex and soon start producing female hormones, female pre-flowers, and, later, female flowers. See chapter 22, Additives, for more information on the hormone ethylene.

Note: Some of the products that release ethylene are plant growth regula­tors (PGRs). See chapter 22, Additives.

Note: Ethylene sprays can be phytotoxic when not diluted properly or when they are applied in hot weather.

Increase Yields
Treat seeds with carbon dioxide (CO2) or ethylene before sowing to strengthen and increase root development, growth, budding, flowering, ripening, seed pro­duction, and overall yield.

Germinated seeds break through soil and still carry the outer cask of the seed. (MF)

A germinated seed turns into a seedling when the rounded cotyledon leaves appear. Cotyle­don leaves will sustain the seedling with nutri­ents throughout the next week or two. (MF)

Strong seeds like the ‘Skunk #1’ on the left germinate quickly and grow up healthy. Weak seeds like the ‘Cantaloupe Haze’ on the right start slowly and might not grow as well. (MF)


When a seed sprouts, its white taproot emerges. Soon afterward the sprout breaks through the soil surface and a pair of cotyledons, also known as seed or seedling leaves, appears. The seed leaves spread out as the stem elon­gates. Within a few days, the first true leaves appear, and the little plant is now officially a seedling. This growth stage lasts for 3 to 6 weeks. During seedling growth, a root system grows rapidly, while green, aboveground growth is slow. Water and heat are critical at this point of development. The new, fragile root system is very small and requires a small but constant supply of water and warmth. Too much water will drown roots, often leading to root rot and damping-off. Lack of water will cause the infant root system to dry up.

As seedlings mature, some will grow fast and strong and appear healthy in general. A little soil heat now will help nurture small seedlings to a solid start. Other seeds will sprout slowly and be weak and leggy. Cull sickly plants, and focus attention on the remaining strong survivors. Seedlings should be big enough to thin out by the third to fifth week of growth. Thinning out seedlings is often very difficult for gardeners who pay exorbitant prices for a few seeds!

This ‘Chronic’ seedling is off to a healthy start in life.

Plants soon outgrow their containers. Roots encircle the inside of smooth plastic contain­ers. This seedling will be transplanted into a larger Smart Pot to promote root growth.

Occasionally a seed or two can be found in normally sinsemilla cannabis buds.

Seedlings need at least 14 hours of light daily. They require less-intense light now and grow well under fluorescent tubes for the first 3 to 4 weeks. CFL or HID light can also be used. Compact fluorescents should be 12 to 18 inches (30–45 cm) and the HID 3 to 4 feet (90–120 cm) above seedlings for best growth.

If not growing in rich organic soil or pre-fertilized mix, start feeding 2 to 4 weeks after seeds have sprouted. Some gardeners wait until leaves yellow to begin feeding. Use a mild quarter-strength solution.

Strong, rapid seedling growth is essential for strong, healthy plants and a bountiful harvest. Take special care to nurture seedlings so they get a good start on life. Any lack or excess of water, light, or temperature will stunt seed­lings. Avoid high temperatures and low light levels, which cause lanky growth. The first 3 weeks of life for autoflower­ing and autoflowering feminized variet­ies are critical. These varieties grow for 70–80 days from seed. Without super strong growth during the first 21 days, yields are much lower.

The seedling stage is over after 3 to 4 weeks of growth. At this point rapid foliage and root growth starts. Rapid growth aboveground is the most obvious signal that the vegetative growth stage is in process. Plants need more room to grow; transplanting into a larger con­tainer is essential to hasten development.

Finding Seeds

Medical Gardeners

Medical cannabis gardeners may have seeds from the plants they are growing. These dedicated gardeners usually know the variety well and can tell you many specific details about growing it, often reciting the qualities of the plant—taste, aroma, and medicinal benefits, etc.—by heart. Cultivate relationships with these expert medical gardeners!

Cannabis médico con semillas

Containers of medical cannabis some­times contain seeds. These seeds are often referred to as “bag seed.” You will know more or less the taste, aroma, and medicinal qualities of the bud the seed came from. However, you will not know the growth characteristics of the plant, and the plant will probably not be genetically stable. Such seeds could grow into magnificent plants and produce many cannabinoid-potent clones, but often these seeds will grow into plants that have only some desirable traits of the parents.

Medical Cannabis Dispensaries

Many medical cannabis clubs and dis­pensaries in California and other states where medical cannabis is legal sell seeds. Google “medical cannabis club,” “medical marijuana dispensary,” and so forth. Often the attendant at the dispen­sary knows the seed producer or breeder and may possess personal information on growing the seeds. This personal information will help gardeners and plants get off to a healthy start.

Seeds are available at shops in many countries. Stores in Canada, Holland, Italy, Spain, Switzerland, United King­dom, and a growing list of other coun­tries sell seeds to the public via retail outlets. Find such seed stores at the web­sites listed in the magazines and cannabis fair guides. A personal conversation with knowledgeable, reputable seed merchants yields precise cultivation information. Ask many questions and request personal stories about favorite varieties.

Retail cannabis seed sales are growing daily. This photo was snapped in Northwestern Spain at the Kaya Grow Shop in Vigo, Galicia.

Ten ‘Granddaddy Purple’ seeds are stored in this clear vial. The cork breathes, allowing air to enter and exit. Such containers are perfect to store seeds for a few months, but not for the long term..

The Oaksterdam Nursery in the “Oaksterdam” district in Oakland, California, supplied medicinal cannabis seeds and clones to licensed caregivers and patients. A US govern­ment raid April 3, 2012, closed the facility. Before closing, more than 15,000 students graduated from Oaksterdam University.

Internet Seed Retailers

Internet cannabis seed purveyors offer the largest selection and best prices over­all. Many medical cannabis gardeners do not have access to seeds at local stores, or the selection at local stores might be very limited.

Note: We do not advise ordering seeds via mail or courier service unless they are legal in your area and also legal to ship through the post. There are many seed sellers that advertise in magazines and on the Internet that send seeds any­where worldwide. We advise to source medical seeds locally and legally.

Caution! Too often seed merchants do not tell the truth about their seed stock in this unregulated industry. They sell seeds that are not what they advertise them to be. Other companies receive payment and do not ship the seeds. It is easy to overcome such problems with a little homework.

Seed Quantities and Pricing

Seeds are generally sold in packages of 5, 10, and 15. Prices range from about $3 to $30 USD per seed. Often less expensive seeds are perfectly adequate for many gardeners’ needs and desires. More expensive seeds are usually more stable, and extra care has been taken to produce them. Furthermore, expensive seeds are often winners of recent canna­bis cups or are more difficult to produce.

SeedsCost EachCost 10 Seeds
autoflowering feminized$5–$10$50–$100

Unless feminized, always purchase pack­ages of 10 to 15 seeds, because the odds are that half of the seeds will be female and the other half male. Of the desired female seeds, some will show more desir­able characteristics than others.

Always open the seed pack or inspect seeds visually before purchasing. Look for weak, moist, or damaged seeds. Growing lists of companies package their seeds in hermetically sealed con­tainers that also prevent tampering.

If you are not going to plant all the seeds in a sealed package at the same time, remove them from the sealed package and store in an airtight container in a cool, dark, dry, place. Keeping seeds dry is essential, or they might start to germinate. Place them in a small dark vial or film canister with a dry packet of silicone—the kind you find in electron­ics packages. Label the crush-proof con­tainer before you place the seeds inside.

Storing Seeds

Store seeds in a sealed, airtight, crush­proof container and include a packet of silicon crystals to absorb moisture. Store seeds in a cool, dark, dry place. Long-term seed storage is most successful at temperatures of 35°F–41°F (2°C–5°C). Replace silicon every 1 to 4 weeks to ensure that seeds stay dry. Place a max./ min. thermometer in the refrigerator to record maximum and minimum tem­peratures and humidity. Make sure to label containers! Some seeds will remain viable for 5 years or longer when stored properly. When 50 percent of the stored seeds do not germinate, the average stor­age life is over. Seeds a year old or older often take longer to sprout and have a lower rate of germination.

Seed hormones—ABA, cytokinins, and gibberellins—are primed to respond to moisture, which is the first signal to germinate. Prevent moisture from signaling seeds to germinate by keeping them dry. Small amounts of moisture in the form of condensation can give seeds a false start on germination and cause them to expend all their stored energy. If possible, avoid moisture levels above 5 percent to ensure viable seed when storing seed long term. Moisture levels above 5 percent will cause germination levels to decrease over time.

Seeds with a thin, outer protective shell never truly go dormant, because mois­ture and air are always present within. This moisture and air cause hormone levels to slowly dissipate. Such seeds do not store well for a long time.

Always check seed packs for crushed or moist seeds or seeds that have started to sprout.

Store seeds in airtight containers along with a packet of silicon crystals to absorb moisture. Make sure to remove, dry, and replace silicon regularly. (MF)

These ‘Skunk#1’ seeds were frozen for 16 years. Note some gray dead tissue on all embryonic leaves. Germination was over 90 percent, and survival was over 80 percent. (MF)