Planting for Summer Shade

A shade tree in the wrong place is just a tree. The difference between a garden that feels 5C cooler in February and one that does not comes down to geometry: which wall the tree shades, at what time of day, and whether it lets the winter sun back in. Get that right and you can cut the load on a west facing living room dramatically. Get it wrong and you have shaded a patch of lawn nobody stands on.

Work out where the heat is actually coming from

In Australia the summer sun tracks high across the northern sky at midday and drops low into the west and north west through the afternoon. Low afternoon sun is the problem. It comes in almost horizontally, straight through windows and onto walls that have already been heating all day, at exactly the hours you are home.

So the priority order for shade planting is:

• West and north west. The highest value position by a wide margin. Shade here cuts late afternoon heat load on walls, windows and outdoor living areas.
• North. Valuable, but only from a deciduous tree, because in winter you want that sun back. A deciduous canopy on the north side blocks high summer sun and admits low winter sun, which is the single most useful thing a tree can do for a house.
• East. Morning sun is mild and generally welcome. Shade here is a low priority unless you have a bedroom that bakes at 7am.
• South. Almost no summer sun hits a south wall in most of Australia. Plant for privacy or looks here, not for shade.

Spend an afternoon in January noting where the sun actually lands at 3pm and 5pm. Ten minutes of observation beats any rule of thumb.

How far from the house to plant

Late afternoon sun is low, so shade is cast sideways rather than downwards. A tree on the west side does not need to be right against the wall to shade it. As a working guide, plant a tree with a 10m mature height about 6 to 10m out from the western wall and its afternoon shadow will cover wall, windows and part of the roof.

Too close creates a different set of problems: gutters filled with leaf, branches on the roof in a storm, restricted air flow against damp walls, and root activity under footings and paving. As a minimum, keep large trees at least 5m from a building and small trees 3m, and give more where the species is known for vigorous roots.

Check what else is up there. A shade tree planted west of the house that also shades the solar array in the afternoon is a false economy, and the same goes for shading a pool that you actually want warm in October. Underground services matter equally, which we cover in our guide to trees that will not wreck your pipes.

Canopy width beats height

Shade is an area, and area comes from spread. A narrow columnar tree 15m tall casts a thin ribbon of shade that moves off your target within the hour. A 10m tree with a 10m spread casts a broad pool that stays useful for most of the afternoon.

When you are reading mature dimensions, treat the width as the number that matters and the height as the constraint. This is also why three medium trees planted 6 to 8m apart usually beat one large one: the canopies merge into a continuous cover, the shade lasts longer as the sun moves, and losing one plant does not lose you the whole scheme.

Deciduous trees for the north and west

• Chinese elm (Ulmus parvifolia). Arguably the best all round shade tree for Australian conditions. Reaches 10 to 15m with a spreading 8 to 12m crown, tolerates drought, clay, heat and pruning, and holds a beautiful branching structure in winter.
• Chinese pistachio (Pistacia chinensis). 8 to 12m, drought hardy, brilliant autumn colour even in warm districts, and a well behaved root system.
• Honey locust (Gleditsia triacanthos cultivars). 4 to 18m depending on the cultivar, with fine filtered shade rather than dense shade, which means lawn and understorey survive underneath. Note that honey locust is a restricted or declared plant in some Australian states and local government areas, so it is worth confirming what applies where you live, and ask us which selection suits the height you have room for. Where it is not the right call, Chinese pistachio and golden rain tree give the same light dappled shade.
• Golden rain tree (Koelreuteria paniculata). 8 to 10m, spreading, summer flower then papery lanterns, tolerant of poor soil and heat.
• White cedar (Melia azedarach). Fast, 7 to 12m, native to northern Australia and through South and Southeast Asia, and extremely tough. Two things to weigh before you plant one. The berries are toxic if eaten, so think carefully with small children or dogs. The wood is brittle and the roots sucker readily if damaged, so keep it well clear of pipes, paving and anywhere you sit.

Two to be careful with. Liquidambar styraciflua gives magnificent shade and colour but reaches 20 to 25m with famously destructive roots and spiky fruit, so it needs acreage. London plane is a superb street tree and a genuine respiratory irritant for many people in spring, which is worth knowing before it goes in beside a bedroom window.

Evergreen trees for year round shade

Where the target is a driveway, a pool deck or a west facing outdoor area rather than a window, evergreen is usually the better answer because there is no winter gap and no leaf drop into a pool.

• Tulipwood (Harpullia pendula). 8 to 12m, dense rounded crown, non invasive roots, Australian rainforest native. One of the best evergreen shade trees for a suburban block.
• Weeping lilly pilly (Waterhousea floribunda). The named screening selections such as Amaroo and Green Avenue hold 8 to 12m, while the straight species reaches 15m and more on a good site. Dense and soft edged, and excellent as both shade and screen.
• Tuckeroo (Cupaniopsis anacardioides). 8 to 10m, glossy, salt tolerant and unbothered by wind, which makes it the coastal default.
• Water gum (Tristaniopsis laurina 'Luscious'). 6 to 10m, compact, tolerant of paving and confined root space. The right choice for a courtyard or a narrow verge.
• Brisbane box, also sold as brush box (Lophostemon confertus). Robust, drought hardy and long lived, and genuinely large at 15 to 30m with a crown to 15m across, so it belongs on a big block or acreage rather than beside a house.

Figs deserve a specific warning. Every Ficus makes wonderful shade and every Ficus has a root system that will find drains, footings and pools. Keep them to parks and large rural blocks.

Fast growing trees and what fast growth costs

Growth rate is a trade off, not a free feature. Trees that put on 1.5 to 2m a year do it with low density wood, and low density wood breaks in storms. Fast growers also tend to be shorter lived, at 25 to 40 years rather than a century, and they usually have vigorous roots to match the top growth.

The better answer is usually a moderately paced, well structured species bought at a size that already has presence. An advanced tree planted at 45L or 400mm is typically 1.5 to 2.5m tall on day one, and a 100L is typically 2.5 to 3.5m. Either is throwing useful shade within two to three summers, which is faster in practice than a small fast grower that spends its first two years recovering from transplant. Our guide to what size tree to buy for impact goes into where that trade off sits.

At the top of the size range, where a project needs a canopy tree of five metres or more on the day it is planted, field-grown ex-ground stock is the answer: Signature Trees grows advanced shade trees in the ground on two Queensland farms and lifts them in a wire basket for delivery by crane.

The mistakes that keep repeating

• Planting in the centre of the back lawn, where the shade falls on grass nobody sits on rather than on the house or the paved area.
• Choosing by height and ignoring spread, then wondering why the shade is so thin.
• Planting an evergreen on the north side and losing all winter sun and warmth into the house.
• Underestimating mature width and planting 3m from a boundary a tree that will spread 10m.
• Planting a single tree where three would have made a continuous canopy over the entertaining area.
• Forgetting that shade over an outdoor area also means leaf, flower and fruit drop onto that area.

Getting it in the ground at the right time

Plant shade trees in autumn or early spring so roots establish before the heat. A tree planted in January into hot dry soil spends its first summer surviving instead of growing.

Because we deliver and plant everything ourselves, position gets decided on site with the tree there in front of you, which is exactly when it becomes obvious whether the shade will land where you want it. Details are on our supplied and installed page. Once it is in, the first summer of watering determines whether it grows or just holds on, and our guide to watering a newly planted advanced tree covers how much and how often.

Browse the species that establish and canopy quickly in our fast growing shade tree collection, or work through the wider tree range if you want to weigh up longevity and structure alongside speed.

Stand in your yard at 4pm on a hot day, mark where you wish the shade was, then pace 6 to 10m back towards the west from that spot. That is where the tree goes.