What is propagation and how do I do it?

What is propagation?

Sexual propagation

This involves a contribution from both male and female plants to create a new plant. It is a natural process in which a parent species create an offspring with different genetics to them. The process begins with flowering, followed by pollination, fertilisation and finally seed formation.

The created seeds when sown form completely new plants. This is the simplest, easiest and most economical type of propagation and has a few advantages.

For some plant, tree, vegetable or fruit species sexual propagation is the only way to reproduce, therefore it is essential. This leads to the ability to create new, better crop species that are stronger, disease-resistant and have a longer life span, whilst also preventing viral transmission from parent plants.

It is the only process which allows for large numbers of crops to be planted all with genetic variation, which is responsible for continuous evolution that keeps producing better offspring. Once the seeds have been created they are easy to be transported and stored.

Asexual propagation

This can also be known as vegetable propagation as it involves producing new plants through vegetative parts of the plant such as roots, leaves, stems, bulbs and tubers. As the new plant is formed from a single parent there is no genetic exchange involved, resulting in the created plants being identical to the parent plant; these are also known as clones.

The most common methods for this process of propagation are by cuttings (see our guide on taking cuttings), division, layering and grafting/budding. There are a few advantages to using this process as it allows plants that do not produce seeds to be grown with only a single parent therefore it will not require pollination or cross-pollination.

Generally, the process of asexual propagation is faster than sexual propagation helping in rapid generation of crops which can retain beneficial traits from the parent plant. Certain techniques can also be used to recover or repair damaged plants.

As stated there is more than one method for asexual propagation, here are a few to get you started...

How to propagate plants

Cuttings

A cutting is a vegetative plant part which is severed from the parent plant and rooted in order to regrow and form a whole new plant. The most common types are stem, tip and leaf cuttings. When planting cuttings a rooting medium is used such as coarse sand, vermiculite, soil, water or a mixture of peat and perlite. These materials are used in order to create a sterile environment, which is low in fertility and drains well in order to provide enough oxygen whilst retaining enough moisture.

Stem cuttings

These are used for plants with a woody or semi-woody stems, such as ivy, azaleas and roses. A length of the stem is cut off and placed in the rooting medium until new roots have formed. It can then be transferred to a plant pot to continue growing.

Tip cutting

These are commonly used for most multi-stemmed plants. A tip about 10-15cm in length is cut from the main stem or a side branch just below a node (where the leaf and stem meet). The lower leaves and flowers are removed and the cut end is dipped in rooting hormone powder and planted in a rooting medium, making sure the leaves are well above the soil. An alternative method without hormone powder is to place the cut tip in water until roots form, after which it can be removed and potted. Once potted keep the base of the pot warm and in a place with plenty of indirect sunlight.

Leaf cutting

This is a similar process to stem cuttings, except a leaf stalk instead of the main stem, is used. There are a few methods for leaf cuttings and the method required will be determined by the type of plant you are propagating.

For some plants, the leaf and stalk can be removed from the parent plant and placed directly upright into the rooting medium, whereas others require some of the small veins on the leaf to be slit, with the leaf lain horizontally over the rooting medium.

Division

There are many plants that grow with several stems which have roots attached to each one. Therefore each of these rooted stems can be separated from the parent plant to create a new plant. If the stems are not joined together they can be gently pulled apart, otherwise, they will need to be divided using a sharp knife. Once the rooted stems have been divided they can be individually potted in the rooting medium to grow.

Layering

This method allows a stem to form its own roots whilst still being attached to the parent plant. There are several forms of layering including tip, simple, compound, mound and air layering, however, each one follows the same general process.

This is where a stem or multiple parts of a stem from the parent plant are manipulated into coming into contact with or being emerged in a rooting medium. A slit is made in the underside of the piece of stem that is in contact with the rooting medium to allow new roots to form, after which it can be separated from the parent plant and potted.

Grafting and budding

This is a form of propagation where plant parts are joined together to grow as one plant as they do not root well as cuttings or their own root systems are inadequate. In grafting the upper part of one plant grows on the root system of another plant, whereas in budding, a bud is taken from one plant and grown on another. This is seen as the most difficult of propagation methods therefore it is mostly practised by experienced nurseries.

These are just a few of the amazing ways in which plants can be propagated. So if you’re looking for a new hobby, a different gardening adventure or the ability to multiply your produce to its maximum potential, propagation could be the ideal opportunity to start something new.