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Trees

Trees are a big commitment in a garden. They take up space and are long lived, but they are also highly beneficial not only within a garden, but also within the wider neighbourhood as they have a wide range of environmental benefits. Trees are usually tall growing, long-lived plants with one main trunk (although some trees are multi-trunked) and have a multi-branched, leafy canopy.

When selecting a tree to grow in a garden consider its ultimate height and width, the shape of its crown (for example spreading, rounded, narrow) as well as whether it is deciduous (that is loses its leaves) or evergreen (retains leaves year round). Trees also bring other benefits to gardens such as flowers, fruit, shade, shelter, and privacy. Many also provide habitat for birds and insects.

The dimensions of any plant should appear on the plant label. Often with a tree, the dimension on a plant label is its size after 10 years, which may not be its ultimate size. To research the mature size of a tree, look at specimens in your local area, nearby park or botanic garden. Your local hardware or garden centre should be able to direct you to mature forms of a tree you are considering.

If a tree species is too large for a suburban garden, look for a named variety, which will be more compact. As well as dwarf or compact forms, there are also trees that are ‘fastigiate’, which means they have a narrow, upright growth habit.

Use the mature width of the tree to position it in the garden so it has space to grow without overhanging buildings (including the house, shed and garage) or the fence line. This will reduce any need for long-term pruning.

Growing conditions

Aspect Most trees need an open, sunny aspect with shelter from strong winds. Where trees are being grown in exposed situations, they may need to be staked until they establish. Note that garden and lawn areas under trees gradually become shaded as the tree grows. Plants growing under trees suffer root competition and compete with the tree for moisture and nutrients.

Soil Trees grow in a wide range of soils but as with most plants do best in deep soil. Enriched the soil with organic matter such as compost or manure or apply Seasol Super Compost before planting. Most trees also need good drainage. Avoid planting trees in areas without good soil depth such as soil overlaying a sub-surface rock layer. Trees grown near retaining walls or pavements can cause problems as their roots grow and expand.

Climate There are trees for every climate. Be guided in your selection by trees that do well in your local climate or seek advice from your local hardware or garden centre.

Tips on planting trees for summer shade

General care

Watering Regular watering is important to help trees become established after planting. Apply Seasol to your young tree every 2 to 4 weeks to help aid tree establishment, strong roots and healthy growth. As trees mature many may need little additional watering except during periods of prolonged droughts where even established trees can require watering. Apply Seasol around the tree’s canopy during periods of heat and frost to help with environmental stress.

Feeding and mulching Trees can be feed via your preferred method, either liquid or granular food or a combination of both, depending on your tree variety.  Keep plants growing well with a granular fertilizer such as Seasol plus Nutrients All Purpose including Natives every 6 to 8 weeks during the growing season. Spread under the dripline of the tree (the area at the edge of the foliage canopy) as this is where the feeder roots are located. Remember to water it in thoroughly after application If you prefer liquid feeding, apply PowerFeed All Purpose including Natives every 2 to 4 weeks during the growing season, around the tree’s canopy. Spread organic mulch such composted bark or inorganic mulch such as gravel under trees to deter weed competition and retain moisture. Mulches are a good option where grass or plants struggle to grow. Don’t build mulch up around the trunk as this can cause fungal problems for the tree.

Pruning Generally good tree selection will reduce any need for pruning. As trees grow however lower branches may need to be pruned to allow open space beneath the expanding canopy. Also remove dead or crossing branches (which are rubbing) cutting flush with the main stem to aid recovery. Encourage an upright central trunk. Trees that develop a forked trunk may be at risk of damage later in life. Where mature trees require pruning, invest in the services of a qualified arborist, who can assess the health and vigour of the tree and prune it safely if it is needed. As a general rule, lopping a tree is not advised as it can generate weak top growth.

Watch for Generally watch out for possums, which browse on some trees. Protect vulnerable trees at planting and when their growth is low and accessible to browsing animals by using a tree guard. Before buying a tree, check for potential pests or diseases that may be problematic for the species being planted. If these are likely to be hard to manage in the future, as the tree matures, select a different tree.