Learn to Propagate Plants
- A great hobby
- Get a real buzz from doing it yourself
- Save more money than you might realise when you don't have to buy your plants
- Produce great gifts for friends and relatives
- Sell your excess
There are 10 lessons in this course:
Methods of Propagation
Propagating Structures and Techniques
Propagating by Cuttings
Miscellaneous Propagating Techniques
Budding and Grafting
Propagation of Specific Plants
Layout and Organisation of a Propagating Area
Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.
Outline the principles of propagating plants by cuttings.
Describe methods of stem cutting propagation.
Describe how to propagate plants from non-stem cuttings.
Describe the materials and equipment used for propagating plants from stems.
Describe a range of growing media and their general characteristics.
Describe how and why cuttings form roots and outline ways to manipulate the formation of roots on cuttings.
Describe the principles for establishing successful plant propagation areas.
Outline the principles of nursery scheduling.
HOW TO PROPAGATE PLANTS
Different plants are propagated different ways. Sometimes your choice of propagation method is made because it is the only way to reproduce that plant species, but on other occasions there may be a different reason (eg. it may be the most reliable, fastest or cheapest method, or the method that produces a better quality plant).
Most plants are propagated most often by either seed or cuttings. Other methods such as division may result in fewer losses, but may be more labour intensive or not suited to producing large numbers of plants. Some methods (eg. tissue culture), can produce large quantities of plants, but could require a big financial investment in equipment.
Propagating plants from seeds is called asexual propagation. It is cheap and simple, and because of this, many more plants are produced from seed then by any other method. Seeds however can be variable in other words they may not always be a replica of the parent plant there could be variations, sometimes only slight. The growth habit and colour may vary between plants grown from the same batch of seeds. This is brought about by a random combination of genetic material from the parents. The genetic make-up of each seed is unique. Plant breeders cross-pollinate plants that are genetically different deliberately in order to find interesting features this produces new varieties or cultivars.
Some plants (various vegetable and flowers), produce seeds that are reliably ‘true to type’ (an example is the Grosse Lisse tomato); but others do not (e.g. flower colours may vary from the parent).
Be aware of the following points:
- Seed-grown plants are often different from their parents.
- Not all plants are grown easily from seed.
- Often seed must experience a certain set of environmental conditions before it will germinate.
- Seed and very young seedlings are more susceptible to disease attack or adverse environments than any other type of plant.
- Seeds have their own store of food to support the new plant in its early stages of life; they don't need fertiliser.
- Some seeds will store easily, while others need very special conditions.
Cuttings are pieces of plant, commonly a stem with a few leaves (but sometimes other parts), which are prepared and treated in a way that encourages them to grow into a new plant.
The most critical decisions are:
- What medium (e.g. potting mix) do you plant the cuttings into?
- How should the cutting be treated as it is forming roots?
- What environment should be provided after you plant them?
There are many different alternatives to each of these three questions.
Most cuttings are pieces of stem, often with some leaves left at the top of the stem. Some plants can be grown from cuttings of other tissue (e.g. a piece of leaf, or section of root, or even part of a bulb, with no stem at all).
Cuttings are usually planted into a mix of freely draining materials such as sand, peat moss, perlite, rock-wool or vermiculite in a plastic pot or tray. Part of the tissue is usually below the surface of the mix, and some exposed above the surface. There are other alternatives – such as planting directly into beds of soil in the open.
Most cuttings need to be kept moist but not excessively wet. Softer tissue is more susceptible to drying out; so needs to be kept in a more humid environment; this can be done by either misting cuttings or putting a plastic or glass cover over them). Some cuttings may need to be shaded. Others may benefit from applications of fertiliser, after the roots have started to form (there is no benefit before the roots form).
Other conditions such as light, temperature and hygiene should be kept appropriate to the requirements of the variety of plant being grown. For most pots of cuttings, the ideal environment is on a clean bench in a greenhouse, where temperature, humidity and hygiene is strictly controlled. For some plants though, cuttings can be struck just as easily in an unheated cold frame or in the open ground, with or without some protection (e.g. a cloche, shade or windbreak). Amateur gardeners often do well placing pots of cuttings on a warm window ledge or an enclosed veranda in their home. The most important requirement is usually to protect the cuttings from excessive heat or cold.
Other things that can be done to enhance development of the cutting will either speed the rate of growth, or improve the percentage of cuttings that succeed. Chemical hormones may be applied to stimulate the formation of either roots, or foliage/shoot growth. Pesticides or disinfectants may be used to prevent diseases or pests. Heating may be used to warm the root zone (i.e. bottom heat), to encourage faster growth of roots; or periodic misting of the foliage to cool the top of the plant, or prevent dehydration of the foliage.