western-queensland-gardening-guide.pdf - South West NRM

shrubs. Some fruit trees such as stonefruit (peaches, nectarines, apricots and plums)
require 30 to 40 cm of sartdy soil while others such as citrus and grapes require 50 cm
or more.
The sandy soil should be kept in place with logs, rocks etc. Beds should be large
enough to accommodate the root system of the plant being grown; for example, 4 m
wide for a mature citrus tree. Trees should be planted in rows for ease of formation of
beds. These beds dry out quickly. The soil structure can be improved by the addition
of organic matter and the soil pH acidified by the use of sulphur and nitrogen in the
form of sulphate of ammonia.
Beds for annual flowers may be treated in the same way as the raised bed for
vegetables, and of course there are some annuals which are more suitable than others.
These are included in the lists at the end of this chapter.
Lawns can be maintained in reasonable condition, with the use of gypsum to improve
the soil structure, and sulphate of ammonia as the nitrogen fertiliser.
is of very poor quality and the soil heavy, it is often best to restrict the area of lawn to
special purpose areas, such as near a barbeque or in a narrow strip close to your
vegetable patch. It's surprising how attractive a garden can be with only a small lawn
area and large areas of shrubs and trees, which can be kept tidy with heavy mulches of
leaves and manures. Lawns are dealt with in more detail in Chapter 2.
As a general rule, it is best to concentrate on the trees and shrubs which are suited to
the environment by being adapted to alkaline and salty soils or by having an annual
water requirement which is similar to the average rainfall. If you wish to have fruitbearing
trees in your garden it is a good idea to have at least a couple of citrus trees
(perhaps a lemon and an orange), or grapes. Raised beds are again the answer in clay
soils, because of the drainage aspect which is an important factor when considering
citrus. Some chemical manipulation can be carried out to advantage. Some other
fruits such as dates are well suited to salty conditions in the lighter soils and some nut
trees like almonds (south of Charleville) are fairly tolerant of alkaline conditions.
Chemical heatmmt of soil
If desired plants are not suited to local soil conditions, chemical treatment of the soil
may be necessary. This treatment is rather expensive for large scale use and if not
used correctly can be dangerous.
In sandy soils chemicals such as sulphur and sulphate of onia can be used very
effectively to reduce the pH to an acceptable level. Water moves freely $through this
type of soil and even bore water helps to keep the salts moving. With care and
common sense a sandy soil can remain productive almost indefinitely.
Clay soils are rather a different proposition. The addition of calcium sulphate in the
form of gypsum can be very beneficial. It improves the soil structure and the calcium
is a necessary plant nutrient.