Space saving techniques
Trees shaped to a single trunk can be spaced as close as 1m apart and grown as a fruiting hedge. For cross-pollination, two or more trees can also be planted into one hole.
Trees grafted with two or three different varieties of the same genus are commercially available and can be found with cross pollinating varieties for fruits that need a pollinating partner.
Miniature peaches, nectarines, apples, plums and pears are available along with narrow, columnar fruit trees that do not need pruning
Citrus can be bought grafted onto dwarf 'Flying Dragon' rootstock.
If you have a north or west facing wall, trees can be trained alongside, using an espalier trellis. This is suitable for apricots, Japanese plums, nectarines, figs, mulberries, peaches and persimmons. Apples and pears prefer south or east facing walls in warm winter areas like the coastal areas of Perth.
In small patios or balconies, miniature fruit trees and blueberry bushes can be grown in containers and all fruit trees can be kept to a manageable size by pruning.
It is important to select fruit varieties which are suited to your climate, and have some resistance to the insect pests and diseases found in your area. Your local nurseries generally have the best information on fruits suitable for local conditions. Deciduous trees like pomefruit (apples, pears, quinces) and stonefruit (peaches, plums, nectarines, cherries) need a certain amount of winter chilling (winter cold) to produce fruit and different varieties will have a different chilling requirement. When choosing varieties, make sure the winter chilling in your area is sufficient for the variety chosen.
Also be aware that certain fruit trees need compatible pollinating partners to produce fruit. These partners are usually a different variety which flowers at the same time. Consult your local nursery for recommended pollinating pairs.
The best time to plant deciduous fruit trees, like apples, pears and stone fruit, is when they are dormant, in winter and early spring. Evergreen fruit trees, like citrus, avocados and olives, establish well when planted in autumn, so they have three seasons to develop their root system before the heat of summer. Avoid planting any fruit trees in summer when conditions are extreme.
Young trees should always come from a reputable source. The soil should be well drained and have no major history of soil diseases or nematodes. Improve the soil structure, water holding capacity and fertility of the soil through the application of compost. Sandy soils should also have 5% clay incorporated into the top 30cm of soil to aid water retention.
When planting a fruit tree dig a hole about 1m wide and half a metre deep. Mix compost, phosphorus (rock phosphate at 1kg per tree, or superphosphate at 500g per tree) and trace elements (100g per tree) with the soil for the planting hole. Clay soil with poor drainage can be improved with gypsum. In most cases if the tree is in a container remove the tree from its pot without disturbing the root ball and plant into the hole. In some cases potted trees can suffer from being 'root bound' which is when the roots have used up all the available space in the pot and may have grown around the pot in a circle. In this case roots may need to be trimmed and thinned out prior to planting to prevent the tree from 'strangling' itself as it grows.
Bare-rooted trees are available from some nurseries in winter. Keep the roots moist during planting; spread the roots on top of the mound of improved soil mixture, then backfill. Keep the bare roots away from direct contact with the fertiliser. The bud union or graft should be at least 5cm above the eventual soil level.
Water the tree in after planting using a soil wetting agent and cover the roots with free-draining wood chip mulch.
In windy or frost susceptible locations, protect the tree with a tree guard which can be constructed from wire mesh and shade cloth.
Trees can be irrigated by either reticulation or hand-watering. It is important to supply enough water for the tree's needs and avoid either over-watering or letting the soil dry out too much. Keep the tree free from weeds, pests and diseases. Unless the tree is dormant, feed with a slow release fertiliser at the recommended rates. To train the tree to a desired shape, start shaping it in the first years after planting.
Most deciduous trees are pruned when dormant but summer pruning can be used for removal of unwanted shoots and suckers, reducing height and to allow sunlight penetration. For trees particularly susceptible to bacterial diseases like apricots and cherries more pruning can be done in summer after harvest as an alternative to winter pruning.
Plants like peaches, nectarines, persimmons, grapes, kiwifruit, blueberries and trailing berries are pruned yearly and plums, apricots, apples and pears are pruned every one to two years. Many fruit trees fruit on one year old wood only (peaches, nectarines, grapes, kiwifruit) and require annual pruning to ensure that new fruiting wood is regenerated.
Every three or four years thin out branches in winter on citrus, figs, nuts, mulberries, feijoas, guavas and tropical fruits.
Most home gardeners train their trees into vase shaped trees or central leader trees. Keeping your fruit trees to a moderate size allows easier picking, pruning and cheaper bird or fruit fly netting.
Pests and diseases
Control pests like snails and slugs with physical barriers like sawdust or shell grit on the ground. Use sticky bands or fluffy quilt wadding Dacron bands on the tree trunks to stop weevils travelling from the soil into the canopy. Hand-pick pests before they escalate to plague proportions.
Avoid the use of strong pesticides which can kill parasitic wasps, ladybirds, lacewings, lizards and frogs which are the natural enemies of pest insects. Try to keep your garden ecologically balanced.
Fruit flies are one of the worst pests of fruit trees in metropolitan Perth and must be controlled. Hang baits in the tree, use splash baits containing spinosad weekly and install fruit fly netting over the trees once the fruit is formed or use exclusion bags on individual fruits.
Appropriate destruction of fruit which fall off trees or which remain on the tree as 'mummies' at the end of the harvest season is important to prevent the build-up of many pests and diseases such as fruit fly, brown rot of stone fruit and apple scab. This should be a routine part of managing your trees.
Citrus branches infected with gall wasp should be pruned off at least one month prior to the expected wasp emergence in spring.
Prune trees so they are well ventilated and get plenty of sun, as this provides less favourable conditions for diseases.
Try not to damage your plants as wounds provide an entry for diseases.