Propagation tips for home gardeners
by PU Chien. Posted on October 7, 2012, Sunday
GARDENERS are always looking for new materials for new plantings and also multiplication. Beautiful and healthy plants really depend on the initial planting materials. There are several ways of getting your own planting materials so that you can be sure of the quality and type of plants.
Take softwood and semi-hardwood cuttings when the mother plant is actively growing. Don’t take cuttings that have flowers as you want all the new planting’s energy to go into forming roots.
Softwood cuttings are best taken from young or newly-matured shrubs. For herbaceous plants such as begonia, dahlia and chrysanthemum, cuttings can be done at any time.
Semi-hardwood cuttings should be taken from either deciduous or evergreen plants at a time when newly matured stems or branches are at the base.
All cuttings must be done with sharp tools so that the cambium cells are not damaged unnecessarily and hopefully remain intact.
Do not add fertiliser to the fresh medium – be it fresh top soil with compost or sand plus soil and compost, or just rooting compost. Cuttings won’t need a lot of nutrients to start rooting.
You can use river sand but not sand from from the sea unless the salt has been removed.
Please remember that fresh cuttings haven’t got roots to absorb water for growth, so the medium should never be too wet or waterlogged as this will only kill the cuttings because the freshly-injured cambium cells and bark would easily rot away.
However, moisture is still a must for new growth. Nurture cuttings by slowing down
natural loss of moisture from the leaves. One way of giving it moisture is to use a plastic bag or container with drips of water. Remember to cut off most of the leaves or at least half of the leaves attached to reduce the transpiration rate.
Some seeding boxes have covers that allow ventilation but prevent transpiration. Some gardeners just invert a transparent plastic drinking cup or bag over small pots to help retain moisture within the micro-sphere. This method is good enough for softwood cuttings.
Allow the cuttings to sit just above the top level of water in the container, just to wet the cut. It is handy to use polystyrene packing materials as the plants can float and not get too wet or drown. Insert cuttings of coleus, fuchsia, begonia or impatiens thorough holes punctured using a stick or screwdriver. Don’t let the leaves touch the water.
Hormones and rock phosphate fertiliser will encourage rooting. Today there are mixed hormones suitable for both softwood and hardwood cuttings. Phosphate is essential for root initiation in plants.
Don’t forget that newly-developed leaves can easily catch the fungal disease Botrytis. The rotting of fresh leaves would be the end of new plantlets and this tends to spread easily in nursery beds. It is therefore vital to find a balance between moisture supply and disease emergence.
Once the cuttings have developed healthy roots, take them out for field or pot planting.
Succulent plants are great because they have enough food reserve in their thick leaves. Examples include Crassula spp, Kalanchoe spp as well as some euphorbia and cacti.
Take a cutting and carefully remove a mature leaf making sure there is a piece of the main stem attached at the base for good propagation. It is best to use sharp secateurs or cutting blades.
Next leave the cutting in a dry and warm place for a day or two to drain any sap or liquid. Sometimes the cutting will develop new ‘eyes’ known as calli. Make sure the callus touches the medium for rooting.
Leave in partial shade and have just a little moisture to keep it damp. New plantlets should be allowed to develop until they are big enough to be handled for potting in a general purpose potting mix.
This method works well with even delicate plants such as African violets and begonias, provided that you can maintain a high humidity.
I hope you will find these tips helpful and be able to propagate plants in your garden on your own.
Happy gardening. Do send me an email for details.