Gardening with Margaret Matthews
Sowing and growing
Plant propagation, part 1
by Margaret Matthews
If we do not have very deep pockets, the cost of creating a new garden or replenishing an established one can make a deep dint in the family budget. I do not consider the price of plants in the average retail nursery unjustified, when once considers the steps that occur before the plant is sold. If it is grown from seed or cutting, it will need re-potting several times before it reaches the nursery shelf. There is the cost of potting mixes, pots, fertilisers, labour. There’s the inevitable loss of some plants through careless handling or watering, and now there is the GST!
It is possible for very little outlay to grow new plants from seeds or cuttings from established plants. As well as growing plants from seed or cutting, they can be layered, grafted or budded. Growing one’s own plants can be a very rewarding and productive hobby. In most cases, cuttings are more readily available than seeds. Plants come true to the parent plant, in habits of growth and in flower and foliage, and shrubs and trees propagated from cuttings flower and fruit much more quickly than plants grown from seeds. It is also a fact that shrubs and trees from cold regions grow and flower well in southern Victoria, but do not produce viable seed because the summers are too long and hot (although not this summer). Many plants from cold regions fail to produce viable seed for the opposite reason.
Stem cuttings
Stem cuttings can be divided into roughly three types of wood:
o softwood cuttings, taken in spring and early summer;
o medium half-ripened wood taken during summer and early autumn; and
o hardwood cuttings taken during late autumn and winter.
There are no fixed dates for the taking of these various cuttings. The times simply merge into each other and if you use your own judgment, through trial and error, you will be able to propagate plants at very little cost. If you wish to propagate a large number of cuttings then you might need access to a glasshouse, or at least a propagator with bottom heat and a plastic cloche to provide humidity. If you just intend growing a few extra plants for your own garden, or to give to friends or as donations to plant stalls, then it will cost very little.
To strike stem cuttings you will need a pair of sharp secateurs, a sharp knife, some clean plastic pots or various sizes, a pack of potting mix specially designed for striking cuttings (you can buy separate ingredients and mix them together, but this is hardly worthwhile). You will also need a small packet of a hormone striking powder, some small plastic or wooden strips to use as labels, a waterproof marking pen, some clear plastic bags to place over pots. You will need a table of comfortable height on which to begin your new hobby, and of course you will need the cuttings, the most essential component.
You should choose a cool day, and when you have taken the cuttings, place them in a plastic bag containing some water. Always take cuttings on a slant so that you can distinguish the top from the bottom, as it is sometimes hard to tell one end from another! As their name implies, ‘tip cuttings’ are from the tips of the branches and can be from five to 75mm in length, sometimes longer. Soft-wooded shrubs such as fuchsias strike well from tip cuttings. Most plants have small nodes or buds at the axil, where the leaf forms, and one or two of these should be below the surface of the potting medium. Some leaves should always be left on evergreen cuttings. With large-leafed shrubs such as camellias, it might only be two or three. The average evergreen cutting possesses numerous small leaves and most of these should be removed, leaving only a few leaves at the tip of the cutting.
‘Heal’ cuttings are usually taken from semi-ripened wood. They are made by giving a sharp tug where the proposed cutting joins the stem. The resulting ‘heel’ is where the roots will form.
To propagate stem cuttings: depending on their size, remember that they seem to prefer to be slightly crowded, so that a small tube can easily take five to ten slim cuttings.
• Dip each cutting into water, and then into the striking powder so that it adheres to the bottom end where the roots will eventually form.
• Fill the pot loosely with the potting medium and insert a number of cuttings into the pot until it is comfortably full.
• Stand the pots in a bowl of water until bubbles form on the surface of the mix. Depending on the weather, it may not be necessary to water again for some time.
• Write the name of the plant and the date on a label and insert in each pot.
• Cover each pot with a plastic bag and group a number of pots together in a sheltered position.
• After a few weeks, up-end the pots, carefully shake out the contents and see if roots have formed or are developing. If so, you must judge if they are ready to be potted on into individual tubes. The plastic bags can then be removed.
• Re-pot the small plants individually into a slightly larger pot, using a good quality potting mix containing nutrients. Label each plant. Water as required.
There are a number of hardwood cuttings that can be propagated in the open ground when they are dormant in winter. They should be about 15 to 20 cm long and buried in the soil for half their length. Roses, grapevines and many deciduous shrubs can be grown in this way.
If you follow these steps you will have new plants for your garden and, hopefully, some to give to friends. Don’t expect to achieve 100 per cent results, as this will not happen. But you will learn from experience and will have found a new hobby.
Next month we will find out how to obtain new plants by layering and the fascination of growing plants from seed.
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