With the extremes of temperatures we have been experiencing, now is a good time to evaluate the performance of different plants in the garden in terms of their tolerance for heat, as well as extended periods of dryness.
It is also valuable to recall, if possible, the planting techniques used when the plant was originally placed into the ground and the subsequent treatment of the plant. This might include a variety of factors such as: mulching, watering patterns, use of wetting agents and shading.
From this information the gardener should be able to make reasonable assumptions about techniques that enable and encourage good, strong growth, as well as recognise plants that adapt well to extremes of temperatures, compared to those that require much more intensive care and attention. This information then becomes very valuable when selecting plants in the future.
Native plants such as the hybrid grevilleas, callistemons, melaleucas and banksias seem to be tolerating the weather conditions well, with minimal requirements for watering.
Some exotics (plants that are not originally from Australia), including abelias and abutilons, are also performing reasonably well while plants such as hydrangeas and fuchsias, seem to require more regular watering.
They may display signs of burning on the leaves but these should be left on the bush until cooler weather arrives or until it is the time for regular pruning. The leaves will provide shelter for inner leaves and growth.
The older leaves will be more tolerant of heat and dryness, while younger leaves such as those that would result from trimming and pruning, will be softer and could be badly affected.
Plants that are showing signs of wilting, despite applications of water, may be suffering from the soil becoming water-repellent. Water-saving crystals can be added to the soil around the pot. A number of products that can be watered onto the soil around the plant are also available. They contain additives that will assist in water retention, lessening water run-off, as well as conditioning the soil.
GOING TO POT
Pot plants are often given as presents at Christmas time. They may be flowering forms of plants or grown principally for their attractive leaf forms and colours.
In general, they will survive for a couple of weeks indoors, however they will eventually require placement in an outdoors situation. There are some exceptions, and the label attached to the plant should be checked for advice pertinent to the individual plant.
Plants that have been kept indoors for an extended period should be allowed to become gradually accustomed to outdoor climatic conditions.
Placing them in a shady area for several days and then moving them to a permanent position will avoid the leaves becoming dried out or burnt from excessive heat. This may occur if the plants experience strong winds, in addition to strong sunlight.
Pine trees that have been used as living Christmas trees should be treated in this way as this will ensure they will be available for use next year.
Plants that are grown indoors on a regular basis usually benefit from being placed outdoors during a period of light rain or some hand watering, as this will refresh the leaves, removing accumulated dust. Ensure that theplants haven't been placed in a position that will receive direct sunlight as this will quickly burn the leaves.
Brassicas, which include cabbage, Brussels sprouts and broccoli, should be watched for attack by caterpillars.
The larval, or caterpillar stages of the cabbage moth and the small cabbage white butterfly are the main causes of damage to the plants.
Cabbage white butterfly is white with distinct black spots on the wings and is around 40mm across. The cabbage moth is greyish and smaller. Both lay their eggs on the underside of leaves.
The larvae of caterpillars hatch from the eggs and then feed on the leaves or fruit. The blue-green smooth textured caterpillar is that of the cabbage white butterfly, while the caterpillar which is green-brown is that of the cabbage moth. They both start eating the outer leaves before moving to the inner heart of the cabbage.
The presence of the butterflies around the plants will be an indication that caterpillars will soon be present.
Some gardeners prefer to catch the butterflies in a simple net, before they lay their eggs. However, if the caterpillars are present, it is often suitable to pick off the caterpillars by hand and then destroy them.
The moths and butterflies are attracted to bright yellow objects. Traps that have a yellow base, covered with a sticky substance, are available, commercially. The flying insects will be attracted to the sticky surface and become trapped there.
Home-made versions, consisting of thick glue applied to a piece of yellow plastic, and suspended near the plants may also be effective. However, these will need to be replaced if they are damaged by rain or watering. A biological control, such as Dipel, might be needed for complete control.
Companion planting, planting plants that repel the butterflies around or near the desired plants is another method used by some gardeners. Aromatic herbs such as lemon balm, sage, borage and rosemary should be effective.