Seed listings, grow guides and forum threads use a lot of shorthand. This glossary explains the words you will see most when you shop for seeds and grow your first plants. Where a definition rests on research, we cite a university or Extension source. Where a term is everyday grower slang, we describe how it is used and say so.
Terms are grouped by topic, so you can jump straight to the section you need: seed types, plant biology, the grow cycle, and buying terms. A short how to section shows you how to use these words to read a seed listing, and a troubleshooting table at the end covers the mix ups that come up most.
Seed and genetics terms
Autoflower. A plant that starts flowering based on its age, not on day length. Cornell University researchers describe autoflowering cultivars as ones that “will flower regardless of day/night length.” Oregon State University Extension notes that autoflower varieties are generally ripe around 75 days after planting, while full season types need closer to 120 days.
Photoperiod. A plant that switches from leafy growth to flowering when nights get long enough. Cornell explains that most hemp cultivars grown for CBD or CBG “will only terminally flower when the night is long enough.” Outdoors, that happens as summer days shorten. Indoors, growers control it with a light timer.
Critical photoperiod. The night length that triggers flowering in a photoperiod plant. Cornell reports genetic variability in critical photoperiod, which means two photoperiod cultivars planted on the same day can start flowering on different dates.
Fast or fast flowering. A seller term for photoperiod plants bred with some autoflower genetics so they finish sooner. They still respond to day length. Read the label as a breeder claim and check the stated flowering time.
Feminized seed. Seed produced so that the plants are expected to be female, the plants that grow the flowers most home growers want. NC State Extension points out that, under the North Carolina Seed Law, “the percentage of feminized seed in the packet is also not addressed.” In plain terms, feminized is a seller promise, so read the seller’s terms.
Regular seed. Seed that can grow into male or female plants. Breeders use regular seed when they want males for making new crosses.
Cultivar. Short for cultivated variety: a plant line selected and kept by people for certain traits. Seed shops usually just say strain instead.
Strain. The common shop word for a named cannabis variety. It is used the same way as cultivar on most seed listings.
Genotype. The genetic makeup of a plant. Two seeds from the same pack can carry different genotypes, especially in regular or newer lines.
Phenotype. What you can see and measure in a plant, such as height, leaf shape, color or smell. It comes from the genotype plus the growing conditions. Growers often shorten it to pheno.
F1 hybrid. The first generation cross of two different parent lines. Sellers use the term for crosses made to be uniform. Check the breeder’s own description for what it means for that product.
Plant and chemistry terms
Hemp and marijuana. Both are Cannabis. Virginia State University Cooperative Extension explains that hemp was bred for fiber and seed, while marijuana “was bred from Cannabis for its production of cannabinoids.” Under federal law today, hemp is cannabis with 0.3% delta-9 THC or less on a dry weight basis, as the USDA explains. The federal hemp definition is changing, but that change currently does not apply before December 11, 2026.
THC. The cannabinoid most linked to the high from marijuana, as the VSU Extension page describes it. Levels on seed listings are breeder stated and vary with growing conditions.
Cannabinoid. A family of compounds made by the cannabis plant. THC and CBD are the best known.
Trichome. The tiny hairs and resin glands on flowers and nearby leaves. Growers look at them with a loupe when they judge harvest timing.
Pistil. The hairlike parts of a female flower that catch pollen. They often change color as the plant matures.
Terpene. An aroma compound. Terpenes give plants smells such as pine, citrus or spice. Our guide to pinene covers one of them at https://kindseed.com/top-10-facts-about-pinene-terpene/.
Grow cycle terms
Germination. The point where a seed cracks and sends out its first root. In North Carolina, NC State Extension notes that a seed label lists a germination percentage and the month and year of the test.
Seedling. A young plant with its first sets of leaves.
Vegetative stage (veg). The leafy growth stage before flowering. Photoperiod plants stay here while nights are short. Autoflowers move through it on their own schedule and flower regardless of day length.
Flowering stage. The stage when the plant grows buds. For photoperiod plants it starts when nights pass the critical photoperiod.
Transplant. Moving a young plant to a bigger pot or into the ground. Oregon State University Extension advises aiming to transplant “just as roots reach the bottom of cells.”
Rootbound. When roots fill a container and start circling. OSU Extension warns that rootbound starts can have “lingering impacts” on growth for the whole season.
Flush. Watering with plain water before harvest. Research on flushing is limited, and our flushing guide at https://kindseed.com/everything-you-need-to-know-about-flushing-cannabis/ covers what is and is not known.
Topping and training. Cutting the main tip or bending stems so the plant grows wider and more even. Many growers go easy on training autoflowers because they have less time to recover.
Harvest, dry and cure. Cutting the plant, drying it slowly, then storing the buds in sealed jars and opening them now and then so moisture evens out.
Mold. Fungal growth on buds or leaves. Do not use moldy material. Our guide at https://kindseed.com/stoner-alert-smoking-moldy-cannabis/ explains what to look for.
Buying terms
Germination guarantee. A seller’s written promise about seeds that fail to sprout. Writing about North Carolina rules, NC State Extension explains, “There isn’t a minimum standard germination for hemp since it is not defined as an agriculture or vegetable seed.” That is why the written terms matter. Kind Seed’s own guarantee applies only to its Weed Seeds Usa White Label seeds, not branded breeder packs, and covers orders up to 3 months old, for orders of 100 seeds or less, when you follow the published method.
Breeder. The company or person who created and keeps a genetic line.
Seed bank or seed store. A shop that sells seeds from one or more breeders. Our list of seed banks for first time growers is at https://kindseed.com/8-best-cannabis-seed-banks-for-first-time-growers/.
White label. Seeds sold under a shop’s own label rather than the breeder’s brand.
Mix pack. A pack with seeds of more than one strain.
How to use this glossary to read a seed listing
- Find the seed type first. Look for feminized, regular, autoflower or photoperiod. This tells you whether you will need to remove males and whether day length controls flowering.
- Check the timing line. For an autoflower, the time is usually counted from sprout to harvest. For a photoperiod, it usually counts only the flowering weeks.
- Match the timing to your season or setup. Oregon State University Extension notes autoflowers are ready around 75 days after planting, so they fit short seasons. Photoperiods outdoors need a season long enough to finish after nights get long.
- Read cannabinoid and yield numbers as breeder claims. They depend on light, soil, water and care.
- Read the guarantee terms. Note the method required, the time window and the proof asked for.
- Write down the strain name, breeder and seed type for each pack, so you can track results and make a claim if you need to.
Troubleshooting
| Problem | Likely cause | What to do |
|---|---|---|
| An autoflower stayed small | Short life cycle, small pot or late transplant | Start in its final pot or transplant early, and read the breeder’s stated size |
| A photoperiod plant flowered too early outdoors | It was planted while nights were still long in early spring | Plant later in the season, or choose an autoflower for early planting |
| A feminized plant showed male flowers | Feminized seed is a seller promise, not a law | Remove the plant early and report it under the seller’s terms |
| Seeds did not sprout | Old seed, storage or method | Follow the seller’s germination method, then check the guarantee terms |
| The listing uses a word not on this page | New slang or a brand term | Ask the seller what it means before you buy |
A term with no clear source is a reason to ask questions, not a reason to guess. If a seller cannot explain a term on its own listing, that tells you something too.
Legal note
Seed and home grow rules vary by state and locality. Check the rules where you live before you buy or plant. For more terms and guides, visit the Kind Seed blog at https://kindseed.com/seed-bank-blog/.
Sources: Cornell University, Flowering Time in Hemp (https://hemp.cals.cornell.edu/resources/reports-factsheets/2022-cornell-hemp-field-day-handouts/flowering-time-in-hemp/). Oregon State University Extension, Planning a drought resilient hemp crop (EM 9628) (https://extension.oregonstate.edu/catalog/em-9628-planning-drought-resilient-hemp-crop). NC State Extension, Buying and Selling Hemp Seed in NC (https://hemp.ces.ncsu.edu/news/buying-and-selling-hemp-seed-in-nc/). Virginia State University Cooperative Extension, Industrial Hemp FAQs (https://www.ext.vsu.edu/industrial-hemp-faqs). USDA Agricultural Marketing Service, Hemp (https://www.ams.usda.gov/rules-regulations/hemp).
FAQ
What is the difference between autoflower and photoperiod plants?
Autoflower plants start flowering based on their age. Photoperiod plants start flowering when nights get long enough. Cornell University researchers note that autoflowering cultivars flower regardless of day and night length.
What does phenotype mean in cannabis?
Phenotype means the traits you can see and measure in a plant, such as height, leaf shape and smell. It comes from the plant’s genetics plus its growing conditions, which is why two plants from one pack can look different.
Are feminized seeds guaranteed to grow female plants?
No. Feminized seeds are meant to grow female plants, but it is a seller promise. NC State Extension notes the percentage of feminized seed in a packet is not addressed by the North Carolina Seed Law, so read each seller’s terms.
What is the difference between hemp and marijuana?
Both are Cannabis. Virginia State University Cooperative Extension explains that hemp was bred for fiber and seed, while marijuana was bred for its production of cannabinoids. Under federal law today, hemp has 0.3% delta-9 THC or less on a dry weight basis. A change to that definition currently does not apply before December 11, 2026.
What does a germination guarantee mean?
It is a seller’s written promise about seeds that fail to sprout. Terms differ from seller to seller, so check the method required, the time window and the proof needed. Kind Seed’s guarantee applies only to its White Label seeds, not branded breeder packs, and covers orders up to 3 months old, for orders of 100 seeds or less.