Using your greenhouse to develop new varieties

Hybridising is a simple process – when plants are left to themselves outside, wind or insects will do the job for you. Unfortunately they will not also identify the pollen parent. It is impractical to carry out controlled pollination with plants growing out of doors unless they individually covered, which is rarely practical. This means growing parent plants in a greenhouse, a situation that most of us do anyway but which we don’t exploit to create our own new plants!

Popular plants for this kind of experiment include day lilies, yuccas, lewisia, passionflower, and anything called F1 hybrid. These are plants you can easily raise in your greenhouse and use to create new varieties. An F1 hybrid means first generation offspring, from two plants that have been bred. The F1 may have desired qualities of either or both parents and this is something you can produce yourself!

To cross-pollinate first select the seed parent and remove the petals and all the anthers. This is done for two reasons - first, it makes the flower less attractive to would-be pollinators, second, it prevents self pollination.

Various methods can be used to transfer pollen to the seed parent. A brush or feather is often recommended, collecting the pollen in the fibres and brushing it onto the seed parent stigma. First test the pollen is ripe, by carefully touching it with the very tip of your finger – it will transfer from the anther to your flesh if it is ready. Then grasp the filament of the anther with tweezers and gently brush the anther against your brush or feather before transferring it to the seed parent stigma, making sure you coat it with pollen. Deciding when the stigma is receptive is more complex, but if the pollen sticks to it readily, it probably is. Early in the season it is fairly safe to leave the pollinated flower exposed but as soon as flies appear it is necessary to isolate the flower for a few days under a plastic cloche. Remember to identify the parents by hanging a label from the stem marked with the name of the pollen parent so you can reproduce your best results.