Sex/ Male & Female

What percentage of these seeds will be female?

It is usually best to assume a female/male ratio of 50:50. Therefore, germinate twice as many seeds as you intend to grow. In practice, the natural femae/male ratio is more like 65:35. This is because cannabis spreads its pollen through the air, without the need for pollinating insects, and therefore requires fewer males than females.
Particularly difficult (low temperature and humidity) or stressful conditions during the early part of a plant's life may marginally increase the chance of that plant becoming male or hermaphrodite.

When can I tell whether they are male or female?

Cannabis will only show its sex once flowering has begun. Cannabis begins to flower when it receives 12 hours of light and 12 hours of uninterrupted darkness in each 24-hour cycle. Once this light cycle (or photoperiod) is initiated, the first flowers should be visible within 2 weeks.
Inside, it is the decision of the grower when to alter the photoperiod and induce flowering. This is achieved by simply adjusting the timers on your lights.
Outside, the grower must wait until the natural daylight hours have decreased to 12 per day. Exactly when this occurs will, of course, vary depending on your locality. In Northern Europe it happens around mid-to-late July.
It is possible to induce flowering outside by allowing your plants 12 hours of daylight each day, then covering them or taking them inside. This must, however, be done every day without fail.

How can I tell whether they are male or female?

Female flowers are distinguished by their white hairs, which first appear in pairs at the top of the stem and branches and at the internodes where branches emerge from the stem. These hairs will increase in number, thicken into clusters and change colour from white to orange as flowering progresses.
Male flowers may be recognized by the pairs of tiny pods (initially, smaller than a match-head) in the same locations. They too will quickly increase in number. Soon after forming, these pods will open into mature male flowers which will then distribute pollen.
A diagram showing a male and female plant appears on our website and in our current catalogues.

Why must I remove the male plants from my garden?

In a natural environment, where male and female cannabis plants are allowed to grow together unimpeded, male pollen will enter the air, stick to the hairs of the female flowers and form seeds. The female flowers or buds familiar to most cannabis-lovers are actually unfertilised seed pods which, given normal conditions, would contain dozens or hundreds of seeds.

The unpollinated female flower of the cannabis plant contains the highest concentration of THC (the prime active ingredient in cannabis). The female flower is made up of clusters of calyxes, each of which produces a pair of hairs (pistils). The calyxes and pistils are covered with tiny, THC-rich resin glands whose purpose is to protect the flower-cluster and to help pollen adhere to the pistils in order to reproduce. Once pollination occurs - when a pollen grain adheres to a pistil long enough transfer its genetic information - that calyx will stop producing new resin glands and begin forming a seed.

Therefore, a female flower that has been exposed to more than a few grains of pollen will almost always be less potent than an unpollinated one. Seeded buds also weigh far less once the seeds have been removed. This is why the term Sinsemilla (or sin semilla - without seed) is traditionally applied to high quality cannabis from all over the world.

A female plant at the start of its flowering-cycle will display few calyxes - singles or pairs at each internode. If such a plant is heavily pollinated, ie if all or most of those calyxes receive pollen, then it is quite possible for that plant to cease production of new calyxes and spend the rest of its life-cycle producing seeds in the few initial calyxes. In this case, the plant will not grow the oversized buds seen in most modern hybrids.

Do you sell feminised seeds?

Yes, Sensi does sell feimised seed. See: feminised cannabis seeds