A cutting is a piece of stem, root or leaf which is removed from a plant, then treated in a way that stimulates it to grow roots, stems and leaves; hence producing another new plant.
Cutting propagation can be carried out on a very wide variety of plants, and after seed propagation, is the most commonly used method of producing new plants. Cutting propagation is most commonly used for shrubs, indoor plants and many herbaceous perennials. As a general rule, it is not as commonly used to propagate most types of trees.
This book sets out how to grow plants by cuttings, including:-
- different types of cuttings,
- where to obtain suitable material for cuttings,
- how the cuttings can be treated to increase the likelihood of success,
- different materials and equipment used to take and strike the cuttings,
- how to take cuttings of a range of popular plants.
Propagation by seed or spore is known as sexual propagation. Propagation by non-sexual methods is known as vegetative or asexual propagation. Other types of asexual propagation are layering, budding & grafting, separation and division.
The Importance of Cuttings.
Plants are reproduced by cuttings for a number of reasons, including:
*Cutting grown plants are identical to their parent.
A cutting grown plant is identical (genetically) to the parent plant (the plant from which the
original cutting was taken from). This is not necessarily so when plants are grown from seed.
Cuttings are the most widely used technique for reproducing "true to type" plants. This ensures that
the unique characteristics, such as leaf variegation or flower size & colour, of the parent plant are
perpetuated in the progeny. When a plant is grown from seed, the flower and foliage effects, for example, can be different to the effects on the parent plant
*It is easier to produce new plants from cuttings
For some types of plants, seed production is difficult, due to one or more of the following reasons:
a/ The plant doesn’t produce viable seed, or produce seed at irregular times,
b/ Seed is difficult to germinate (e.g. Boronia, Eriostemon),
c/ Seed that is difficult to collect, for example, plants that have seed pods that burst open
dispersing the seeds widely,
d/ Seed is produced at a time when seed cannot be collected, or collection would require
a further trip to the area (often very difficult for remote areas), or can only be collected
with difficulty (e.g. plants whose seed matures during wet seasons when access may be
limited).
* Producing plants that flower or fruit sooner
Many plants grown from seeds go through a juvenile stage, in which flowering, and hence seed
production do not occur. Some plants may take 5, 10 or even more years before they commence
flowering. Once a plant has flowered, plants propagated from that plant by cuttings will avoid the
juvenile stage and flower early, often within months of the cutting having struck.
Many plants also have undesirable growth forms when they are young. These include very
vigorous growth, thorniness, or unattractive foliage or form. By taking cuttings from adult plants
these undesirable characteristics can be avoided.
* Maintaining juvenility
In some cases the juvenile form of a plant may have characteristics that are more desirable than
those of the adult form. A good example of this is the smaller, immature foliage of the Hedera helix
cultivars (English Ivy). For some plants cuttings will strike more readily from juvenile material.
WHERE TO GET YOUR CUTTINGS
You may take cuttings from plants growing in gardens, pots, parks or in the wild; and you may successfully produce new plants from cuttings taken from any source; however, you will always get much better results if you carefully choose your source of cuttings.
-If you know the cultivar name of the plant, you can be more certain of how to propagate
it, and be confident of the characteristics that will be demonstrated by the new plants.
-If you take cuttings from healthy plants; they are more likely to develop roots faster, and
produce healthier plants quicker.
Genotype versus Phenotype
Genotype is the genetic makeup or 'blue print' of an organism. When a plant is propagated by asexual means the genotype of the newly propagated plants, or progeny, will be identical to that of the parent plant. The phenotype of a plant is it's actual appearance and behaviour. The phenotype of a plant arises from the interaction between the genotype of the plant and the environment in which the plant is growing. Factors such as soil conditions, exposure to light, moisture levels, pollutants, pests and diseases, and nutrition will all have an impact on how a particular plant will grow. This means that a batch of cuttings, propagated from the same parent will have an identical genetic makeup, but once planted out there may be some differences between them in outward appearance and performance, such as foliage colour or height, as a result of environmental conditions.
If a plant is propagated due to its appearance and growth habit in a particular district, the resultant plants may not be identical to the parent when it is grown in a different locality, for example, a plant that grows to 2m in one locality is propagated and promoted with those attributes, but may grow up to 4m in a different locality due to factors such as different climate and soil type.
This highlights the importance of selecting plant material with desired traits for use in a specific locality only, or that the progeny is grown (tested) in a variety of environmental conditions (i.e. soil types, climates) before its attributes are described in promotional materials.
Why Cuttings
Despite all the difficulties that can be experienced with various techniques to propagate a plant, the cutting technique still remains one of the easiest and cost effective techniques to produce a number of new plants, whether that be for commercial or domestic production.
The home gardener will find that cuttings are easy, time effective and cheap. The rewards in watching a plant produce roots and develop into a new plant encourages them to propagate even more plants and share them with friends etc.
Commercial production nurseries know the benefits of the cutting technique. Their profit and existence relies upon using the right technique for the right plant. Improving their techniques can increase production and hence increase profit.
Growing plants by cuttings can be a very rewarding exercise, and for commercial propagators may be the most economically viable method for many plants. This book will hopefully provide a valuable resource to anyone with an interest in cutting propagation.
How to grow a Cutting
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 (eg. 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 materials such as sand, peat moss, perlite, rockwool or vermiculite. Part of the tissue is usually below the surface of the mix, and some exposed above the surface.
The cuttings should then needs to be kept moist, and other conditions such as light, temperature, humidity and hygiene should be kept appropriate to the requirements of the variety of plant being grown.
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 (ie. 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.
This article is based upon extracts from John Mason's book "Propagating from Cuttings".
If you want to get even more serious, study Cutting Propagation in our 100 hour distance learning course See http://www.acs.edu.au/courses/cutting-propagation-309.aspx