Why are there seeds in my buds?

Q: Why are there seeds in my buds?

Seeds in cannabis buds mean the flowers were pollinated, usually weeks before harvest. With no male in the room, the usual source is a hermaphrodite: a female growing anthers, often hidden inside the buds. Herm-prone plants are mainly the result of poor breeding, and stress reveals them. Find the source, cull the herm, and don't grow the seeds: they carry the same tendency.

Short answer

Seeds in your buds mean the flowers were pollinated, usually weeks before harvest. If there was no male in the room, the pollen almost always came from a hermaphrodite: a female growing anthers, often hidden inside the buds. Herm-prone plants are mainly the product of poor breeding, and stress reveals them (House position). The biology here is Supported.

Why

Cannabis is dioecious. Females are XX and males XY, and a well-bred female stays female ^[2]. A seed needs pollen, so seeds point to male flowers somewhere.

Hermaphrodite anthers make working pollen. In a controlled study, anthers formed in clusters next to the stigmas from about week 4 of flower, their pollen germinated 10–30% in vitro, and seeded inflorescences held 22–48 seeds ^[1].

Sex expression is heritable. In hemp, how much male and female flowering a plant shows has a genetic basis ^[3]. Stress such as light leaks or heat triggers intersex flowers in susceptible plants. GenetixBay's position is that this reveals weak genetics rather than creating them.

Seed from herm pollen is almost all female ^[1], so the seeds you found are untested feminised seed carrying the same tendency.

The numbers

Fact	Value
Herm anthers appear	From about week 4 of flower ^[1]
Herm pollen germination	10–30% in vitro ^[1]
Seeds per seeded inflorescence	22–48 ^[1]
GenetixBay herm threshold	Above 2% in tester grows disqualifies a line

What to do

Look for the source. Check bud interiors, nodes and the leaves below for bananas, pollen sacs and pollen dust.
Bag any plant with anthers before moving it, then take it out of the room.
Check the dark period for leaks, and check the timer logs and canopy heat. Fix whatever triggered it.
Pick seeds out before use. Don't plant them or pass them on.
Record the event and tell the breeder of the line.
Next run, buy seed from breeders who publish herm rates with plant counts.

Common mistakes

Blaming only the light leak and keeping the clone.
Saving the seeds as "free feminised seed".
Calling late bananas normal. They aren't.
Missing anthers hidden inside dense buds.

Full article: Hermaphrodite cannabis (bananas and nanners)
Answers: how to prevent herms · can you smoke a hermie? · growing bag seed
Article: breeders vs pollen chuckers
Terms: hermaphrodite · sinsemilla · nanners

Pollination is the transfer of pollen onto a female flower's stigmas; in cannabis it is usually by wind, or by hand when breeders pollinate chosen branches to make seed.In cannabis growing, a plant (usually female) that develops both pistillate and staminate flowers or anthers; botanists call it intersex or monoecious expression.The pollen-producing part of a stamen; in cannabis each male flower has five anthers that split to shed wind-blown pollen.Herm-prone describes a line whose plants often produce intersex flowers; GenetixBay treats this as a breeding fault and a reason not to breed from it.Having male and female flowers on separate individual plants; drug-type cannabis is naturally dioecious with an XY sex-chromosome system.A male flower that carries stamens (anthers on filaments) and no functional pistil; in cannabis, five drooping sepals around five pollen-shedding anthers.The sticky, hair-like tip of the female pistil that catches pollen; each cannabis female flower has two, white when fresh and darkening with age.Heritability is the share of a trait's variation within a population that is due to genetic differences rather than environment, on a scale from 0 to 1.Hemp is cannabis grown for fibre, seed or other uses and, in many laws, defined as Cannabis sativa with no more than 0.3% THC by dry weight.A light leak is unwanted light entering the grow space during the dark period; in flower it can delay or disrupt flowering in photoperiod cannabis.Feminised seed is seed made by pollinating a female with pollen from another female (or itself) that was chemically reversed, so nearly every seed grows into a female.Germination is the stage where a viable seed absorbs water, splits its shell and pushes out a root (radicle), usually within 1-7 days at 20-30 °C.The herm threshold is GenetixBay's two-tier herm standard: a 10-plant screening grow with zero herms to be featured, then about 150 or more community-grown plants before a line can be Verified under 2% herm rate.Nanners (bananas) are exposed, banana-shaped anthers on a female flower: a hermaphrodite trait, not a normal part of late flowering, and a reason to cull.Pollen is the fine powder released by male flowers that carries the male gametes; when it lands on a female's stigmas it fertilises the ovules and produces seed.A plant count limit caps how many cannabis plants a person, household, patient or licence holder may have, and defines what counts as a plant.

Follow-up questions

Can a female plant make seeds without a male?

A female cannabis plant only makes seeds if pollen reaches it. With no male present, the pollen almost always came from a hermaphrodite, a female growing male anthers, either the seeded plant itself or a neighbour. Pollen can also come in on clothes or from outdoor plants. Look inside buds and at nodes for yellow bananas and pollen sacs.

Should I plant seeds I found in my buds?

Do not plant seeds found in buds from a hermaphrodite plant. Research shows seed from hermaphrodite pollen gives almost all female plants that carry the same herm tendency, so you would be growing unstable, untested feminised seed. GenetixBay's breeder standard is to cull herm-prone plants and never breed from them. Buy seed from breeders who publish herm rates with plant counts.

How many seeds does a pollinated bud make?

A pollinated cannabis bud can hold dozens of seeds. In a controlled study of hermaphroditism in commercial indoor cannabis, seeded inflorescences held 22–48 seeds, and seed formation diverted resources and lowered quality. One open herm can seed many buds on many plants, which is why the source plant must be bagged and removed as soon as you find it.

Sources

Punja ZK, Holmes JE., 2020. Hermaphroditism in Marijuana (Cannabis sativa L.) Inflorescences: Impact on Floral Morphology, Seed Formation, Progeny Sex Ratios, and Genetic Variation. Frontiers in Plant Science 11:718. doi.org/10.3389/fpls.2020.00718

Divashuk MG, Alexandrov OS, Razumova OV, Kirov IV, Karlov GI. 2014. Molecular cytogenetic characterization of the dioecious Cannabis sativa with an XY chromosome sex determination system. PLoS ONE 9(1):e85118. doi.org/10.1371/journal.pone.0085118

Faux AM, Berhin A, Dauguet N, Bertin P. 2014. Sex chromosomes and quantitative sex expression in monoecious hemp (Cannabis sativa L.). Euphytica 196(2):183-197. doi.org/10.1007/s10681-013-1023-y