Whether natural or manual: pollination is the step key to setting off the production of fruit from flowers.
Meet the pollinators: vid of insects pollinating flowers on my chilli plants.
The pods that one is after when growing chilli peppers are part of the reproductive cycle of the plants. They contain the seeds that new plants can grow from.
Chillies spread their seeds over large distances by the aid of birds. Birds are immune to capsaicin due to a lack of receptors, so pepper pods are part of their natural diet – seeds included. In contrast to the digestive system of mammals, the one of birds won’t destroy the seeds entirely but rather roughen up their surface. This will actually help the seeds to germinate once a bird has disposed of them.
On the flower of a chilli plant, there are both male and female parts. Pollination is what brings the two together, and thereby initiates the reproduction process (i.e. the production of pods).
The male part of the flower are the stamens. In the pictures above and below, they are the dark bits protruding from around the center of the flower. They produce pollen which holds the male half of the genetic information.
The flower’s female part on the other hand is the carpel. It’s a composite organ formed by ovary, style and stigma. The ovary carries the other half of the genetic code and holds what will later develop into seeds. It’s the green area that makes up the center of the flower. From it protrudes the (white) elongated style with the stigma at its tip. The stigma receives the pollen, which then travels through tubes in the style to the ovary for fertilisation.
The outer leaves of the flower (called petals) are only needed to attract pollinators. So once the ovary has been fertilised, the plant won’t support them anymore, and they will begin to wilt and eventually fall off. The ovary however will continue to develop into a pod.
Except for some very rare wild varieties, chillies generally are self-pollenizing. Therefore each plant can reproduce with pollen it has produced itself.
However, chillies are not self-pollinating. This means they are incapable of putting the pollen onto the stigma all by themselves. They need someone else to jump in and do the job for them.
In nature or in open spaces such as my balcony, pollen is usually being transferred from the stamens onto the stigma by either the wind or by a range of different insects known as pollinators. Particularly bumblebees, wasps, hoverflies, green laced wings and even moths feel attracted to chilli flowers.
They like to collect and eat the pollen and the nectar which the flowers produce. When an insect dives into a flower for that matter, it keeps touching the stamens, thus causing pollen to be released. As you can see pretty well in the picture above, the pollen will get stuck all over the insect’s body which will also touch the stigma and eventually transfer the pollen.
In the video embedded at the beginning of this article you can have a closer and more extended look at how a bumblebee and a hoverfly go to work on my plants. Funnily, hoverflies are oftentimes being confused with wasps because of their mimicry, while in fact they are completely harmless.
If you’re growing chillies indoors, though, you’ll have to act as a pollinator yourself. This can easily be done by means of anything like a small brush, a Q-Tip or even one of your own fingers. Simply give the inside of each of the flowers on a plant a slight wiggle with whatever tool you opt for – and you’re done.
A lot of chilli varieties are very apt to cross-pollinating which means they may be fertilised with both pollen of their own and that from other plants. The chances of a successful cross-pollination vary strongly with combinations of different capsicum species, though, as you can tell from this crossing-table. And it will also take some time to even find out if a flower has actually been cross-pollinated. The pod growing from a cross-pollinated flower will not show any signs of the genetic mix, it will always develop according to the genetics of the mother plant (i.e. the plant that the flower was on). Only the seeds in that pod will carry the newly formed genome, so the new genetic makeup will at the earliest show in next-generation plants grown from these seeds.
Some people are looking for seeds that are genetically true-to-type or crosses of particular varieties, so they need to control pollination. While indoors this is no big issue, plants that grow outdoors need protection against the wind and insects pollinating them at random. This might be done by draping either a gauze cloth over an entire plant or a teabag over individual flowers before pollinating them by hand. Personally, I prefer to interfere with nature as little as possible. So I overwinter the plants I like best instead of growing the same variety from seeds again as I did one season before. If you’re very much into collecting and trading seeds you might beg to differ here.