Producing more plants

It can be great fun to grow your own plants. You may already have some experience growing different plants.

Propagation is when you produce more plants.

There are two main methods of propagation or raising plants.

They are:

sexual, where plants are grown from seeds formed as a result of sexual reproduction inside the flower. The plants that grow from seed may not be exactly identical to the parent plant
asexual, where part of the parent plant is taken to make a new plant exactly the same. Stem cuttings are an example of asexual propagation.

To propagate plants successfully you need to know the best method to use for a particular plant.

A geranium plant in flower.

This geranium plant can be propagated either by sowing seed or by taking stem cuttings.

A stem cutting of a geranium. Seed packets.

Advantages and disadvantages of sexual propagation

Sexual and asexual propagation both have advantages and disadvantages. You will be dealing with sexual propagation when growing plants from seeds.

The table below summarises the advantages and disadvantages of sexual propagation.

Advantages of sexual propagation	Disadvantages of sexual propagation
It's a cheap way of growing a large number of plants. Simple equipment and fewer facilities are required than for other propagation methods. Seeds are easy to transport and store. The variation in the plants produced by seed allows plant breeders to develop new varieties. There is a low risk of transferring diseases from the parent plant to the new plant. Some plants can only be raised by seed, for example, annual plants. These plants grow, seed and die in one year. Examples include some vegetables (lettuce) and flowers (sunflower).	Some seeds don't last well in storage – they may die. For example, kauri seed must be sown immediately once it has ripened. Some plants don't produce seeds, such as most varieties of banana. New plants may take a long time to reach maturity (adulthood) when grown from seed, for example, rhododendron. The variation in the plants produced by seed might make it difficult to grow a uniform crop to sell. The plants could mature at different times and show variation in growth. This could be a problem for a market gardener, for example, because not all the crop would be ready to sell at the same time.

Advantages of sexual propagation

Disadvantages of sexual propagation

It's a cheap way of growing a large number of plants.
Simple equipment and fewer facilities are required than for other propagation methods.
Seeds are easy to transport and store.
The variation in the plants produced by seed allows plant breeders to develop new varieties.
There is a low risk of transferring diseases from the parent plant to the new plant. Some plants can only be raised by seed, for example, annual plants. These plants grow, seed and die in one year. Examples include some vegetables (lettuce) and flowers (sunflower).

Some seeds don't last well in storage – they may die. For example, kauri seed must be sown immediately once it has ripened.
Some plants don't produce seeds, such as most varieties of banana.
New plants may take a long time to reach maturity (adulthood) when grown from seed, for example, rhododendron.
The variation in the plants produced by seed might make it difficult to grow a uniform crop to sell.
The plants could mature at different times and show variation in growth. This could be a problem for a market gardener, for example, because not all the crop would be ready to sell at the same time.

Sunflowers are annuals grown from seed.

Avocado plants take a long time to mature when grown from seed.

Complete Activity 1A in your workbook

Complete Activity 1B in your workbook