Those with established gardens know the enormous benefits that trees provide, be it cooling summer shade, a place to relax under or essential habitat for birds, animals, and insects. But how do you grow a tree and gain all those benefits when you have a small backyard?

Words and photographs Kim Syrus

Viewing Adelaide from Windy Point, across a sea of roofs and tree tops you would think we are doing pretty well as a green-canopy city. So, it may be surprising to learn that a recent study, commissioned by the state government, found that currently three quarters of Adelaideans live in suburbs with less than 20 per cent tree cover. That means that among Australia’s capital cities, Adelaide ranks well down that canopy list. Fewer trees means more sunlight hitting the ground, which raises temperatures and creates a heat island effect (whereby urbanised areas experience higher temperatures than outlying areas).

The State Government’s recent Interim Report on The Urban Forest Inquiry highlighted the Conservation Council of SA’s estimate that Greater Adelaide is losing 75,000 trees a year due to development and general clearing; a shocking number of trees disappearing from our landscape.

Smaller, subdivided blocks, coupled with larger homes being built, have squeezed many new gardens into relatively tiny spaces and even existing gardens, resplendent with mature trees, are being cleared across Adelaide’s suburbs as single houses make way for multiple dwellings.

For the increasing number of homeowners faced with a space-challenged yard, the important question is: “Where can I fit in a tree?”.

The good news is that there are trees growing under six metres in height that are perfectly suited to these smaller spaces. And it might help to redefine how we categorise a tree; if you take away the traditional notion of a naturally occurring, long slender trunk and rounded canopy, add some timely trimming, and you have a world of new tree options to plant out.

Firstly, look up and observe which trees your neighbours are planting and plant something different. Changing up the species in your area introduces diversity in foliage, flowering and habitat, which are all key to helping create a vibrant ecosystem that encourages more pollinators and birds into your garden. Also, where you can, try to place trees near your neighbours’ trees, making it easier for your winged and legged visitors to move between them; cluster plantings where three or four properties connect is smart.

While the plant label is a good guide to a tree’s mature dimensions, growing conditions – be it soil type or exposure to wind – will also influence mature height and width.

Drop by your local garden centre to see what small tree options work in your locale. The staff are a valuable resource to tap into.

Here are some “limited spaces” tree suggestions:

Fruit Trees
While home gardeners often tend to gravitate toward ornamental varieties when talking trees, the most obvious option for a dimension-challenged area is fruit trees. Apples, apricots, peaches, and of course citrus, all tick the box when it comes to height. If you go down the deciduous path, you’ll enjoy beautiful blossom, followed by a thick covering of shade giving foliage, then a bounty of produce to pick and eat.

Alternatively, evergreen citrus will give you full-time cover and fruit to boot. Either way you’re a winner. When planting out stone and pome fruit, decide if you want to grow with a central leader upright-style, or with base and lower branching. That first cut will dictate. Leave the main shoot and trim off the lower branches for upright growth and more trunk, or chop off that main leader to encourage lower branching and a ‘V’ shape.

Crepe myrtle
Fast becoming the Adelaide tree, crepe myrtles love this city. Happy sitting on a road verge or tucked in a garden bed, they are super tough and colourful. Available in hues of white, pink, mauve and red, their blooms are a spectacle from summer to autumn. Trim off lower branches to open the base or leave alone, it’s your choice. Thriving in full sun, crepe myrtles can also take some part-shade.
A deciduous beauty, the thick protective canopy drops away to let in rays of warming winter sun.

Ornamental pear
“Festivity” and “Mini Capital” are a few new compact varieties of ornamental pear. These reduced versions make top shade trees for smaller gardens and have a beautiful covering of single white flowers in the spring. They follow that flourish with green glossy summer foliage and finish with spectacular autumn foliage of red, orange and yellow colours.

Bottlebrush
Among the Callistemon choices, you will find plenty that are tall-space fillers. But some lower pruning as they grow produces trunks with branching canopy. Depending on the cultivar, bottlebrush’s ornamental flower spikes can grace a garden from mid-winter to autumn. Nectar-filled blooms are a magnet for birds and insects alike. Other native plants such as banksia and acacia also have tree cultivars that work equally well in smaller yards.

Little Gem magnolia
Not to be confused with deciduous magnolias, Little Gem and its relatives, such as Kay Paris, are evergreen. A pyramidal grower, the thick canopy of glossy, deep green with reddish-brown reverse leaves, adds a focal point to the yard. Through spring and summer enjoy the large white blooms dripping in perfume. A very robust plant, Little Gem prefers well-drained soil and part-shade to full-sun.

Prunus ‘Oakville Crimson Spire’
Looking for a tree that doesn’t have a spreading top canopy? Then Prunus Oakville Crimson Spire is ideal. A true upright grower, there is a burst of beautiful blossom followed by a column of rich burgundy growth from mid-spring to late autumn. Though ornamental, it even produces a small crop plum for either yourself or the possums and birds to enjoy.

Quandong
Quandong are attractive, small evergreen trees that deserve more space in South Australian gardens. A desert dweller, they are aptly suited to a climate-changing environment. The bright shiny orange-red fruit hang like Christmas baubles and are a highly nutritious addition to the home menu.

Woolly bush
If space is tight and brushing past a scratchy tree an issue, try a woolly bush (Adenanthos sericeus). Normally grown for its top-to-soil lush silvery green and incredibly tactile velvet-to-touch foliage, if you trim off (or “leg up”) the lower branches and expose the trunk, it quickly turns this shrub into an ideal small space tree. Wonderfully hardy.

Mop tops
There are many tree varieties grafted atop tall trunks. Known as mop top or standards, these umbrella-like options allow access and space underneath and broad cover overhead. Grevillea, robinia, crab apple, mulberry and flowering cherry are just some available in this versatile form. Plant a few and let their canopy touch to create a leafy alfresco space.

 

This article first appeared in the Autumn 2024 issue of SALIFE Gardens & Outdoor Living magazine.