Cannabis Seed Types Explained for Beginners

Autoflower, Photoperiod, Regular, Feminized, F1, S1, BX, Landrace, and More

For the aspiring cultivator, the journey begins long before the first scoop of soil is placed into a pot. It begins with a single, critical decision: the selection of the seed. This choice is not merely a matter of picking a flavor or a potency level; it is a selection of biological programming. The seed is the software that drives the hardware of your garden. It dictates the plant’s life cycle, its size, its resistance to pests, its nutritional requirements, and ultimately, the quality of the harvest.

In the modern era of horticulture, the terminology surrounding cannabis genetics has become increasingly complex. A beginner looking at a seed catalog is confronted with a wall of jargon: F1, S1, IBL, Autoflower, Fast Version, Backcross. These are not empty marketing buzzwords; they are precise scientific descriptors derived from botany and Mendelian genetics. They tell you exactly how stable a plant will be, how much variation you can expect between siblings, and whether the plant will rely on you—or its own internal clock—to decide when to produce flowers.

Understanding these distinctions is the difference between a garden that operates like a well-oiled machine and one that descends into chaos. This report serves as an exhaustive field guide to cannabis seed types. We will strip away the hype and focus on the botany, the breeding history, and the practical implications of each category. We will explore the mechanics of photoperiodism, the evolutionary adaptation of autoflowering genetics, and the chemical ingenuity behind feminization. By the end of this document, you will possess the knowledge to look at any seed packet and understand the biological promise contained within.

Note: The cultivation of cannabis is subject to varying legal restrictions worldwide. This report is strictly educational, focusing on botanical science and agricultural classification. Readers must verify and adhere to all local laws and regulations regarding the purchase, possession, and germination of seeds in their specific jurisdiction.

The Labels Beginners See and What They Mean

Before we descend into the deeper mechanics of plant biology and genetic inheritance, it is essential to establish a baseline vocabulary. When you visit a reputable supplier or read a breeder’s description, you will encounter a specific set of labels. These are the “primary colors” of the cannabis genetic palette. Here is a plain-language orientation to the twelve most common terms, defining what they mean for you as a grower.

Photoperiod

This describes the vast majority of cannabis strains. These plants function like most seasonal crops; they rely on the length of the night to trigger flowering. As long as the days are long (18 hours of light), they stay in the vegetative (growing) stage. They only bloom when the nights get long (12 hours of darkness).

Autoflower

These are the rule-breakers. They possess a genetic trait that allows them to flower automatically based on their age, regardless of how much light they receive. They are typically faster and smaller than photoperiod plants, acting on a fixed internal timer.

Feminized

These seeds have been bred to eliminate male chromosomes. In a pack of feminized seeds, 99% of the resulting plants will be female (flower-producing). This maximizes efficiency for home growers who do not want to waste space on male plants that produce pollen instead of buds.

Regular

These are seeds as nature intended them, produced by a male pollinating a female without chemical intervention. They produce a population that is approximately 50% male and 50% female. They are the primary tool for breeders who wish to create their own new strains.

Landrace

A landrace is an indigenous variety of cannabis that has evolved naturally in a specific geographic region (such as the mountains of Afghanistan or the jungles of Thailand) over centuries. They are adapted to their local climate and have not been crossed with modern foreign genetics.

Hybrid

A hybrid is the offspring of two different parents. Most modern seeds are hybrids, created by crossing a Sativa with an Indica, or two different hybrids together, to combine desirable traits like flavor, yield, and potency into a single package.

F1 (Filial 1)

This refers to the first generation of offspring from two distinct, unrelated parent lines. True F1 hybrids are prized for their vigor and uniformity. They tend to grow faster and stronger than either of their parents due to a phenomenon called heterosis.

S1 (Selfed)

S1 seeds are created when a female plant is induced to pollinate itself. The resulting seeds are “selfed.” This is essentially a way to copy a specific female plant in seed form, though it can carry risks of genetic instability if not done correctly.

Polyhybrid

This is a hybrid made by crossing two other hybrids (e.g., crossing a Gelato hybrid with a Kush hybrid). These are complex genetic cocktails. While they produce elite flowers, the seeds often produce plants that look very different from one another (high variation).

IBL (Inbred Line)

An IBL is a strain that has been bred with itself for many generations to stabilize its traits. It is a “true breeder.” If you plant 10 seeds of an IBL, all 10 plants will look nearly identical.

Fast Version

These are photoperiod plants (they still need long nights to flower) that have been bred with a recessive autoflower gene. This genetic tweak makes them flower much faster than normal photoperiods, shaving 1–2 weeks off the harvest time.

Heirloom

Heirloom refers to landrace genetics that have been taken out of their native country and preserved by growers in a new location for many years. They are “old school” varieties that have been kept pure by dedicated preservationists.

The 4 Core Seed Categories

Every cannabis seed exists at the intersection of two primary variables: Sex (Regular vs. Feminized) and Flowering Trigger (Photoperiod vs. Autoflower). These four categories form the foundation of all cultivation planning. To choose wisely, you must understand not just what these categories are, but the biological imperatives that drive them.

Photoperiod Seeds

Photoperiodism is the physiological reaction of organisms to the length of day or night. It is a survival mechanism evolved by plants to ensure they reproduce before the harsh conditions of winter arrive. In the context of cannabis, “photoperiod” seeds produce plants that can remain in the vegetative stage indefinitely, provided they receive sufficient light.

The Biological Mechanism The mechanism behind photoperiodism is governed by a pigment called phytochrome, which acts as the plant’s biological eye. Phytochrome detects the ratio of red light to far-red light. During the daylight hours, the plant accumulates one form of this pigment. During the darkness, it slowly converts to another form. When the dark period is uninterrupted and sufficiently long—typically reaching a critical threshold of 10 to 12 hours—the concentration of flowering hormones (florigen) rises to a level that signals the plant to cease vegetative growth.

This shift causes the plant to stop producing stems and fan leaves and begin producing reproductive organs—flowers in females and pollen sacs in males. This sensitivity to the “long nights” of autumn is why photoperiod plants are the standard for controlled cultivation.

Why They Exist and Who They Suit

Photoperiod seeds are the preferred choice for commercial cultivators and serious hobbyists who desire control. Because the grower acts as the sun, they determine exactly when the seasons change.

• Vegetative Control: A grower can keep a photoperiod plant in the vegetative stage for as long as necessary. This allows for extensive training techniques. You can top the plant, bend it, weave it through a trellis (SCROG), or grow it into a massive bush. If the plant suffers a nutrient deficiency or pest attack, you can simply delay the flowering phase, allowing the plant weeks to recover and regrow healthy foliage before switching the lights.
• Cloning: Photoperiod plants are the only viable option for keeping “mother plants.” A mother plant is kept in permanent vegetative state (18+ hours of light) and used to provide cuttings (clones) for years.
• Yield Potential: Because you can grow the plant as large as your space permits before triggering flowers, photoperiod plants generally offer the highest yield potential per plant.

Common Misunderstandings

Beginners often shy away from photoperiods because they fear the complexity of light cycles. They worry about “light leaks” (where light entering the dark period confuses the plant). While it is true that photoperiods require total darkness during their night cycle to bloom, they are often more forgiving than autoflowers because mistakes made in the vegetative stage can be fixed with time. With a photoperiod, you have an eraser; with an autoflower, you do not.

Autoflower Seeds

Autoflower seeds represent a fascinating evolutionary divergence in the cannabis genome. They contain genetics from Cannabis ruderalis, a subspecies native to the harsh, unforgiving climates of Siberia, Central Asia, and Eastern Europe.

The Biological Mechanism

In the high latitudes of Siberia, the summer is incredibly short, and the “days” can last nearly 24 hours during the solstice. A plant waiting for “long nights” to trigger flowering would wait forever, eventually being killed by the early frost. To survive, Cannabis ruderalis evolved to ignore the sun. Instead of relying on light cycles, it developed a timer based on physiological age and metabolic accumulation.

Modern autoflowers are hybrids created by crossing high-potency photoperiod strains (Indica or Sativa) with ruderalis. Through selective breeding, the breeder locks in the ruderalis “automatic” flowering trait while retaining the potency and flavor of the photoperiod parent. The result is a plant that begins flowering after a set period—usually 3 to 4 weeks of growth—regardless of whether it is receiving 12, 18, or 24 hours of light.

Why They Exist and Who They Suit

Autoflowers are designed for speed and stealth.

• Speed: An autoflower can go from seed to harvest in 8 to 11 weeks total. This allows outdoor growers in cold climates to harvest in mid-summer, avoiding the autumn rains that bring mold.
• Size: Because their vegetative time is limited by their genetics (usually just 30 days), they rarely grow massive. Most finish under 1 meter in height, making them ideal for closets, balconies, or small tents.
• Simplicity: There is no need to change light timers or worry about light leaks disrupting the flowering cycle.

The “Dwarf” Risk The greatest misunderstanding about autoflowers is that they are “easier.” In some ways, they are harder. Because the plant will flower at week 4 no matter what, any stress during weeks 1–3 is catastrophic. If you overwater, burn the roots, or stunt the plant during the seedling stage, it will not recover. It will simply flower while it is still 4 inches tall, resulting in a “micro-plant” with a negligible yield. They require a mistake-free start.

Regular Seeds

Regular seeds are the natural baseline of the species. When a male plant releases pollen and it lands on the stigmas of a female plant, the resulting seeds are regular. They carry a mix of X and Y chromosomes.

The Sex Ratio

In a standard pack of regular seeds, the ratio of males to females is generally 1:1, though environmental factors can sometimes skew this slightly. This means if you germinate 10 regular seeds, you should expect roughly 5 males and 5 females.

Why They Exist

For the casual grower who just wants buds, regular seeds seem inefficient. Why pay for soil and electricity to grow a plant that you will eventually chop down and throw away (the males)?

• Breeding: Regular seeds are the only way to get male plants, which are necessary for creating new F1 hybrids.
• Genetic Stability: Many old-school growers and preservationists argue that regular seeds produce stronger, more stress-resistant plants. They have not been subjected to the chemical reversal processes used to create feminized seeds, and some believe this results in a more robust “true” expression of the lineage.
• Mother Plants: Regular females are often preferred for mother plants because they are believed to be less prone to hermaphroditism over long periods of time compared to feminized mothers.

Who They Suit

Regular seeds are for breeders, connoisseurs hunting for specific phenotypes, and growers who want to experience the full natural expression of a strain. They require the grower to be vigilant and Sex the plants (identify gender) early in the flowering stage to remove males before they release pollen.

Feminized Seeds

Feminized seeds are the dominant product in the modern market. Through chemical intervention, breeders manipulate the plant’s reproductive biology to ensure that the seeds lack male chromosomes.

The Science of Feminization Cannabis sex determination is largely hormonal, specifically influenced by ethylene. High ethylene levels encourage female flowers; low ethylene encourages male flowers. To create feminized seeds, a breeder takes a female plant (XX chromosomes) and sprays it with a solution—typically Silver Thiosulfate (STS) or Colloidal Silver.

The silver ions in the solution block the plant’s ethylene receptors. The plant, unable to detect ethylene, panics and produces male pollen sacs in an attempt to reproduce. However, because this “male” is genetically female, the pollen it produces carries only X chromosomes. When this female-derived pollen is used to pollinate another female plant, the resulting zygote is XX. There is no Y chromosome available. Therefore, the resulting seed is 99.9% guaranteed to be female.

Why They Exist and Who They Suit

Feminized seeds are tools of efficiency.

• Space Optimization: If you have a legal limit of 4 plants, planting 4 regular seeds is a gamble—you might end up with 4 males and zero harvest. With feminized seeds, 4 seeds equal 4 harvestable plants.
• Resource Management: You do not waste nutrients, soil, or light on plants that will be discarded.
• Ease of Mind: Beginners do not need to worry about identifying males or the risk of accidental pollination ruining their crop with seeds.

The Core Categories

The following table summarizes the functional differences between these categories, providing a quick reference for decision-making.

Feature	Photoperiod	Autoflower	Regular	Feminized
Flowering Trigger	Light Cycle (12/12)	Age (Time)	N/A (Depends on Photo/Auto)	N/A (Depends on Photo/Auto)
Typical Life Cycle	4–6+ months (Variable)	2–3 months (Fixed)	N/A	N/A
Size Potential	Large / Huge	Small / Compact	Standard	Standard
Sex Ratio	Depends on seed type	Depends on seed type	~50% Male / 50% Female	99% Female
Cloning	Easy and common	Difficult / Not recommended	Yes	Yes
Recovery Time	High (can extend veg)	None (on a timer)	High	High
Best For	Control, Yield, Training	Speed, Small Spaces, Stealth	Breeding, Genetic Stability	Efficiency, Flower production

Genetics Labels: What You Are Really Buying

Once you have selected the category (e.g., Feminized Photoperiod), you must navigate the descriptions of the genetic lineage. Terms like “Landrace,” “Hybrid,” and “IBL” describe the history and stability of the plant.

Landrace vs. Heirloom

Landrace refers to the original, indigenous varieties of cannabis. These are populations of plants that evolved in isolation in specific regions of the world over thousands of years. They are open-pollinated by the wind, meaning they have a wide gene pool but have stabilized specific traits to survive their local environment.

• Sativas: Landraces from equatorial regions like Thailand, Colombia (Colombian Gold), and Mexico (Acapulco Gold) tend to be tall, thin-leaved, and mold-resistant to handle humidity. They flower for a long time (14+ weeks) because the tropical sun never drops significantly below 12 hours.
• Indicas: Landraces from the mountainous regions of Afghanistan (Hindu Kush) and Pakistan are short, stocky, and fast-flowering to reproduce before the harsh mountain winter. They produce heavy resin to protect against UV rays and cold.

Heirloom is a term used to describe landrace genetics that have been transported out of their region of origin and preserved by humans in a new location. For example, if a traveler brought Hindu Kush seeds to California in 1978 and growers have been reproducing them there ever since, those are Heirlooms. They are genetically “pure” in the sense that they haven’t been crossed with other strains, but they may have adapted slightly to the California climate over 40 years.

Hybrids and Polyhybrids

Hybrid is a broad term for the offspring of two different varieties. The vast majority of cannabis sold today consists of hybrids. The goal of hybridization is to combine the best traits of two parents. For example, crossing a Thai landrace (great high, unmanageable height) with an Afghani landrace (sedative high, manageable height) might create a plant with a soaring high but a shorter, faster growing structure.

Polyhybrid refers to a cross between two existing hybrids. This represents the current state of the “hype” market. For example, if you cross Gelato (which is a hybrid) with Wedding Cake (which is a hybrid), you are creating a polyhybrid.

• The Stability Issue: Polyhybrids are often genetically unstable. Because their parents were already mixtures of many different traits, the offspring can be unpredictable. This is often described as a “genetic soup.” While some polyhybrids produce spectacular individual plants, the seeds may vary wildly, with some looking like the mother, some like the father, and some like a grandparent.

Stabilized Lines (IBL)

IBL stands for Inbred Line. This is the Holy Grail of breeding for consistency. An IBL is a strain that has been bred with itself or its close relatives for enough generations (usually F5 or beyond) that it becomes “true-breeding.” This means the gene pool is homozygous for most traits.

• Why it matters: If you plant 10 seeds of a true IBL (like the original Northern Lights or Skunk #1), all 10 plants will look, smell, and grow almost exactly the same. Beginners often find IBLs easier to grow because they behave predictably. They are the opposite of the chaotic polyhybrid.

Breeding Shorthand That Confuses Everyone

Breeders use a specific shorthand derived from Mendelian genetics to track the lineage of their seeds. This code—F1, S1, BX—is not just for scientists; it is a consumer protection label that tells you how much variation to expect.

F1 vs. F2 vs. F3

This refers to the “Filial” generations—the generations of offspring following a cross.

• F1 (First Filial Generation): This is the result of the initial cross between two distinct, unrelated parents (Parent A x Parent B).
  • The Magic of F1: True F1 hybrids often display “Hybrid Vigor” (heterosis). They grow faster, yield more, and are more robust than either parent. Importantly, F1s are usually uniform. If you cross a pure Purple strain with a pure Green strain, the F1 offspring might all be uniform in color.
• F2 (Second Filial Generation): If you take a male and a female from the F1 batch and breed them together, you get the F2 generation.
  • The Explosion of Variation: This is where Mendelian genetics gets interesting. In the F2 generation, the genetic deck of cards is reshuffled. Recessive traits that were hidden in the F1 parents suddenly reappear. You will see a massive range of differences: tall plants, short plants, purple ones, green ones, potent ones, and weak ones.
  • Why buy F2? Beginners usually avoid F2s because they are inconsistent. However, breeders and “pheno hunters” love F2s because they are treasure chests. The rare, “unicorn” phenotypes often appear in the F2 generation.
• F3, F4, F5: If a breeder selects the best plants from the F2s and breeds them, they create F3s. Continued inbreeding (F4, F5) narrows the gene pool, reducing variation and stabilizing the strain into an IBL.

S1 Seeds (Selfed)

S1 seeds are the result of “selfing.” A female plant is reversed (using STS spray) to produce pollen, which is then used to pollinate itself.

• The Goal: S1 is used to preserve a specific elite clone. If a grower finds a one-in-a-million plant (like the original Chemdog or Gorilla Glue #4), they cannot breed it with a male because the male’s DNA would change the offspring. By selfing it, they mix the plant’s DNA with its own.
• The Result: The offspring are not identical clones (that requires cuttings), but they are highly similar to the mother.
• The Risk: S1 seeds reinforce all traits of the mother, including weaknesses. If the mother has a hidden tendency to hermaphroditism, the S1 seeds will likely carry that trait strongly.

Backcross (BX)

BX indicates a “Backcross.” This technique is used to lock in specific traits from one parent.

• The Process: A breeder creates a hybrid (Parent A x Parent B). They then take the offspring and breed it back to Parent A. This is BX1. If they do it again, it is BX2.
• Why buy BX? BX seeds are generally very stable for the traits of the recurrent parent. If you buy a “Blueberry BX,” you can be confident it will smell and taste like Blueberry, because the breeder has hammered those genes into the line repeatedly.

Phenotype vs. Genotype

This is the source of the most common beginner complaint: “My plants don’t look like the picture on the box!”

• Genotype: This is the genetic code written in the seed’s DNA. It outlines the potential. For example, the genotype might say, “This plant has the capacity to turn purple if the temperature drops below 15°C.”
• Phenotype: This is the physical expression of that code in your specific garden. If your garden never drops below 20°C, the plant stays green.
  • Analogy: Think of a pack of seeds like a litter of puppies. They all have the same parents (Genotype), but one puppy is big and calm, while another is small and energetic. Each puppy is a different Phenotype.
• Pheno Hunting: This describes the process of growing many seeds (10, 20, or 100) of the same strain to find the single best phenotype—the “keeper.” Breeders keep this winner as a mother plant for cloning. As a beginner growing from seed, you are essentially doing a small-scale pheno hunt every time you pop a pack.

Marketing Language vs. Real Biology

The cannabis industry is ripe with marketing terms that often obscure the biological reality. A savvy grower learns to read between the lines.

“Fast Version” / “Early Version”

These seeds are a brilliant application of genetic dominance. They are not autoflowers, but they are related.

• The Genetic Trick: To create a Fast Version, a breeder crosses a standard Photoperiod Female with an Autoflower Male. The result is an F1 hybrid.
• The Mechanism: The autoflowering gene is recessive. Because the offspring only get one copy of it (from the father), they do not autoflower. They remain photoperiod plants. However, the presence of this “hidden” auto gene makes the plant’s metabolism highly sensitive to the flowering trigger.
• The Result: These plants react instantly to the shortening days. They often finish flowering 1 to 2 weeks faster than a standard photoperiod strain. This makes them excellent for outdoor growers in northern climates who need to beat the frost, but who want the size and yield of a photoperiod plant.

“Premium” vs. “White Label”

• Breeder Packs: These are seeds produced, tested, and packaged by the geneticist who created them. You are paying for the years of work spent stabilizing the line.
• White Label (Bulk Seeds): Many seed websites do not breed their own seeds. They buy seeds in bulk (by the kilogram) from large industrial farms, often in Spain or Eastern Europe. They then package these generic seeds and slap a popular name on them.
• The Reality: If you buy “White Widow” from a white label seller, you are likely getting a generic white strain, not the specific genetics of the 1995 original. While these seeds can be viable and produce decent weed, they are rarely the specific “elite” genetics they claim to be. Beginners are safer sticking to reputable breeders to ensure they get what they pay for.

Chemovar Labels: CBD, THC, and The Ratios

For decades, we classified weed as “Indica” (sedative) or “Sativa” (energetic). However, modern science shows that the chemical profile—the Chemovar—is a better predictor of effects.

• Type I (THC-Dominant): These plants contain high THC (>0.3%) and low CBD. This represents 95% of the recreational market. They produce the classic psychoactive “high”.
• Type II (Mixed Ratio): These plants contain a balanced mix of THC and CBD, often in 1:1 or 2:1 ratios.
  • The Insight: Type II plants are often the best choice for beginners or medical users. The presence of CBD modulates the THC, reducing anxiety and paranoia while providing a more clear-headed, functional experience. They are harder to find but worth the search.
• Type III (CBD-Dominant): These are high CBD, low THC (<0.3%) varieties, often legally classified as hemp. They offer relaxation and anti-inflammatory properties without intoxication.
• Type IV (CBG-Dominant): A newer category emerging from breeding programs, focusing on Cannabigerol (CBG), the “mother cannabinoid.”

Probability, Not Destiny

It is important to note that seed labels for ratios (like 1:1) are probabilities. In a pack of CBD seeds, you might get some plants that are 2:1 and others that are 1:2. This variation is normal in Type II genetics.

How to Choose Seeds as a Beginner

Do not choose a seed because the picture looks cool. Choose based on your constraints. Use this logic flow to determine the right category for your situation.

The Space Constraint

• Small Tent / Closet (Height < 1.5m): You have a vertical limit.
  • Recommendation: Indica-dominant Autoflowers or Indica Photoperiods.
  • Avoid: Landrace Sativas or “Haze” strains. These plants undergo a massive “stretch” when flowering begins, often tripling in height. A 30cm plant can become a 120cm monster in three weeks, growing right into your lights.
• Large Room / Outdoor: You have the luxury of height. You can explore Sativas and large hybrids.

The Time Constraint

• Need a harvest ASAP?
  • Recommendation: Autoflowers. They are the sprinters of the cannabis world, reliably finishing in 70–90 days from seed.
• Have patience?
  • Recommendation: Photoperiods. While they take longer (adding 4–8 weeks of vegetative time), the yield is typically significantly higher. The return on investment (grams per watt) is usually better with photoperiods if you have the time.

The Climate Constraint (Outdoor Growers)

• Short Summers (North/Cold): If your local climate turns cold and rainy in October, you are in a race against rot.
  • Recommendation: Autoflowers (planted in June, harvested in August) or Fast Versions (harvested late September). Standard photoperiods may not finish until late October or November, by which time they will be destroyed by mold.
• Long Summers (Mediterranean/South): You can grow almost anything, including long-flowering Sativas.

The Experience Goal

• “I want to learn the craft”: Choose Feminized Photoperiods. They are forgiving. If you make a mistake in the vegetative stage (like nutrient burn), you can simply wait, let the plant recover, and then flip to flower. You control the timeline.
• “I just want buds with zero hassle”: Choose Feminized Autoflowers. They require less management, though you must be careful not to stunt them early on.
• “I want to breed my own seeds”: Choose Regular Seeds.

Common Beginner Mistakes When Buying Seeds

1. Buying Only One Seed Genetics is a game of probabilities. Even the best breeder cannot guarantee 100% germination or perfection. If you buy a single seed and it fails to sprout, or grows weakly, your entire grow is stalled. Always buy a pack (3, 5, or 10) to ensure you have backups and can select the strongest seedling.
2. Over-Trusting Yield Numbers Breeders often list yields like “500g per square meter.” Beginners often take this as a promise. In reality, this number is achieved in a professional facility with CO2 enrichment, perfect climate control, and expert feeding. As a beginner, expect to achieve 30% to 50% of the listed yield on your first run.
3. The “Bag Seed” Gamble Beginners often find a seed in a bag of dispensary weed and plant it. This is risky. A seed found in a bag of high-quality bud usually comes from a hermaphrodite (a female plant that stress-produced pollen). Seeds from hermaphrodites are genetically predisposed to being hermaphrodites themselves. You risk growing a plant for months only to have it self-pollinate and ruin your harvest.
4. Misunderstanding “Stability” Beginners often expect every seed to look exactly like the catalog photo. Unless you are buying a highly stabilized IBL, expect variation. This is not a defect; it is nature. Embrace the fact that your plant is a unique individual.

Storage and Viability Basics

A seed is a living embryo in suspended animation. It is waiting for three things to wake up: Moisture, Heat, and Oxygen. To store seeds, you must deny them these triggers while protecting them from damage.

The Enemies of Storage:

Humidity: This is the biggest killer. Humidity fluctuations cause the seed to expand and contract, or even worse, trigger the germination hormones. If the seed starts to wake up and then dries out again, it dies.

Heat: High temperatures increase the metabolic rate of the seed, causing it to burn through its stored energy reserves.

Light: UV light degrades the organic compounds inside the protective shell.

How to Store Seeds Properly:

Short Term (Weeks): A cool, dark drawer is sufficient.

Medium Term (Months/Year): The refrigerator is the gold standard (approx. 4°C / 40°F). However, refrigerators are humid environments. You must place the seeds in an airtight container (like a glass jar with a rubber seal) to keep the moisture out.

Desiccants: Always include a desiccant pack (silica gel) in the jar to absorb any ambient moisture. Note: Do not use rice as a desiccant. It is less effective than silica and can introduce pests (weevils) or mold spores into your seed jar.

Long Term (Years): Freezing is possible, but risky. If the seed has too much internal moisture, the water will expand when frozen and shatter the cell walls, killing the seed. Professional seed banks dry seeds to very specific moisture levels before freezing. For the home grower, a dedicated spot in the fridge is safer and sufficient for 3–5 years of viability.

Testing Viability:

How do you know if an old seed is still good?

Visual Inspection: Healthy seeds are typically hard, have a dark or mottled (tiger stripe) color, and a waxy sheen. Pale, green, or white seeds are usually immature and will not grow.

The Crush Test: Gently squeeze the seed between your fingers. If it crumbles or cracks, it is dead. A viable seed is hard as a rock.

The Float Test Myth: Many growers suggest floating seeds in water to see if they sink. While sinking can indicate viability, soaking a seed in water triggers germination. You should only put a seed in water if you intend to plant it immediately. Do not “test” seeds you plan to store.

Key Takeaways

Photoperiods offer control; Autoflowers offer speed. Choose based on your patience and your climate.

Feminized seeds are for efficiency. They guarantee a flower-producing canopy. Regular seeds are for breeding and genetic preservation.

F1 Hybrids are the vigor sweet spot. They are generally uniform and strong. Polyhybrids (hybrid x hybrid) offer elite flavors but high variation between siblings.

Genotype is the script; Phenotype is the movie. The seed provides the potential, but your environment directs how the plant actually turns out.

Fast Versions are not Autos. They are photoperiod plants with a “hair-trigger” for flowering, ideal for beating early frosts outdoors.

Chemovars matter. Don’t just look at Indica/Sativa. Look at the THC/CBD ratio (Type I, II, or III) to predict the effect.

Storage is simple: Cool, dark, and dry. An airtight jar in the fridge with a silica pack is the best practice for home growers.

Respect the laws. Biology is fascinating, but legal compliance is mandatory.

60-Second Beginner Checklist

Use this checklist before you click “Checkout” to ensure you are buying the right genetics for your situation.

• [ ] Constraint Check:
  • Growing in a small closet? -> Autoflower (Indica dominant).
  • Growing outdoors in the North? -> Fast Version or Autoflower.
  • Want to learn training techniques? -> Photoperiod.
• [ ] Sex Check:
  • Want buds only? -> Feminized.
  • Want to breed? -> Regular.
• [ ] Stability Check:
  • Want uniformity (plants look the same)? -> Look for IBL, S1, or established F1 lines.
  • Don’t mind variation? -> Polyhybrids are fine.
• [ ] Effect Check:
  • Want high intensity? -> Type I (High THC).
  • Want mild/functional? -> Type II (1:1 THC:CBD).
• [ ] Quantity:
  • Did you buy at least 3–5 seeds? (Never rely on just one).
• [ ] Source:
  • Is this a reputable breeder or a generic bulk reseller?