Plants may be propagated in two ways, the most common method being Sexual Propagation and this is through seeds. It involves the fertilization of the female part of the plant by pollination from the male parts, usually from a different plant of the same species. This is normally carried out by natural means, for example insects brushing against the stamens of one plant and transferring pollen to the stigma of another. This transfer of genetic material may also occur when pollen is borne by the wind from one plant to another. This type of propagation may be carried out artificially by lightly brushing the stamens of one plant and manually transferring pollen to the stigma of another.
This propagation by seeds is the most common method of propagation, and seeds should be used that are guaranteed for their freshness and purity. Seeds can either be purchased from retailers or collected from the flowers that have "gone to seed". When collecting seeds it is most important to collect them from healthy plants as some plant diseases can be passed on by the seeds. Flower heads should be placed in a paper bag (plastic may induce mould) and stored somewhere warm and dry. Pod seeds (peas, beans etc.) can be placed on a tray in a dry place and the seeds collected when the pods are ready to split open. Seeds from soft fruit (e.g. tomatoes or peppers) should be removed from the fruit and left to dry before storing.
In order to maintain quality it is more common to propagate plants asexually. This type of propagation is known as Asexual Propagation and involves taking cuttings or slips from the "mother" plant and either forcing the cutting to shoot forth new roots or by grafting it onto a different root stock. The advantages of asexual propagation are that the new plant will be genetically identical to its "mother". Although it is possible to grow new plants from cuttings by sticking them straight into the growing medium (soil, water, vermiculite etc.) the best results are obtained if the cutting is first dipped into a rooting hormone. This can be in the form of a powder, solution or a gel. The growing medium should be kept moist while the cuttings are taking root and growing – it is important not to let the medium dry out.
© Michael J Mason 2009