Plants for shade: what actually grows on the south side

The bed on the south side of the house is usually the last part of the garden to get sorted, and the part that has cost the most in replacements. Three lots of plants have gone in: one sulked, one went yellow and thin, and the survivor has not grown in two years. The strip under the big tree out the back is worse, mostly bare soil.

The standard answer is to buy shade plants. That is not wrong, but it skips the step that decides whether the planting works. Shade comes in three forms, each failing differently, and working out which one you have is worth more than any plant choice.

Shade is three conditions, not one

Go outside on a clear day at about 11am and again at 3pm and look at the ground, not the sky. Check how much open sky sits above the bed, whether direct sun lands on it, and how damp the soil is 200mm down.

Dry shade

Under established trees, along the drip line of the eaves, against a fence with a tree on the far side. Low light, dry soil and root competition at once. This is the site that defeats most plantings, and it needs the toughest list.

Bright open shade

A south wall, a light well, a courtyard between buildings. Little or no direct sun reaches the bed, though in high summer a south wall catches an hour early and late, and the soil behaves normally. Light levels are higher than people assume, and this is the shade with real choice in it.

Dappled shade

Under an open canopy, where patches of sun move across the ground through the day. Light is broken rather than absent. The variable is water: some canopies leave the ground moist, others take everything going.

Under trees, darkness is not what kills the plant

A mature tree runs most of its feeder roots through the top 300mm of soil, well past the edge of the canopy. A new plant put into that ground competes for water and nutrients against a root system many times larger than its own. The tree wins.

The second problem is rain shadow. A dense evergreen canopy can intercept light rain almost completely, so the soil underneath stays dry through weather that soaks the rest of the garden. Eaves do it permanently. People see a struggling bed, conclude it is too dark, and plant something even more shade tolerant. It dies of thirst just the same.

Test before you buy. A few days after decent rain, dig 200mm down. If the soil comes out dusty, you have a water problem, not a light problem, and the fix is irrigation and mulch rather than a new plant list.

Dry shade: what actually holds on

Expect slow. Plants here stay smaller than the label suggests and take two or three seasons to look established. That is normal, not failure. Keep the palette small: three species repeated reads better than eight struggling. Start in the low maintenance range.

Cast iron plant (Aspidistra elatior) earns its common name. It handles deep shade, root competition and long dry spells, holds its dark leaves year round, and asks for little. Plant 400 to 500mm apart. It does not flower for you, but it is still standing when the rest has gone.

Liriope muscari Evergreen Giant is the workhorse for shaded edges and mass planting under trees: strappy, evergreen, tolerant of dry shade and periodic wet, and it still throws purple spikes in late summer in low light. Space 300 to 400mm apart. The wider liriope range covers narrower forms, and mondo grass fills between stepping stones on a shaded path.

Bright open shade: the south wall

This is the shade people most often underestimate. A south facing bed with open sky above it gets plenty of indirect light and normal soil moisture, so flowering shrubs are back on.

Camellia sasanqua Plantation Pink is the one to reach for first against a south wall or as a shaded hedge. Sasanquas take more sun than japonicas and still flower reliably in bright shade through autumn and early winter, and they clip well. The camellia range also holds japonicas, which prefer the shadier end and flower later.

Hydrangea macrophylla is the traditional south side shrub in cooler and coastal districts, holding its flower heads through summer where full sun would scorch them. It is deciduous, so the bed is bare through winter. Hydrangeas are toxic to dogs, cats and children if leaves or buds are chewed, which matters beside a play area or a dog run. Our hydrangea care guide covers watering and pruning; the hydrangea range has mophead and panicle types.

For colour at ground level without flowers, Heuchera Marmalade and the rest of the coral bells range carry amber, plum and near black foliage all year. They want bright shade rather than deep shade and dislike sitting wet, so plant slightly proud of the surface, about 300mm apart.

Dappled shade under a canopy

Mother shield fern (Polystichum proliferum) is a sound start: an Australian native of cool moist forest, evergreen, and more forgiving of a dry week than most ferns. Soft tree fern (Dicksonia antarctica) gives the vertical layer and comes in trunked sizes as well as pots. On a trunked plant the root mass sits in the trunk, so water down the trunk and into the crown, not just at the base, because a trunk allowed to dry right out rarely recovers. Both want shelter from hot afternoon sun and drying wind more than darkness. The wider fern range runs from bird's nest ferns to sword ferns for pots on a shaded verandah.

Underneath, native violet (Viola hederacea) is one of the few groundcovers that spreads properly in shade and copes with light foot traffic. It flowers most of the year, takes damp ground that would rot other things, and is safe around pets and children. For upright structure in warmer districts, the cordyline range includes palm lily (Cordyline stricta). One flag for family gardens: cordylines can cause vomiting in dogs and cats if the leaves are chewed.

Be realistic about flowering

Flowering is the first thing to go as light drops. Nearly every plant sold as shade tolerant will grow in shade and flower better in more light. In bright open shade, expect close to a full display from camellias and hydrangeas; in dappled shade, a lighter one; in dry shade, plan around foliage.

Gardenias make the point. They are sold as shade plants and will survive in shade, but perfume and flower count depend on several hours of bright light, so in a dark corner you keep the plant and lose the reason you bought it. Across the flowering shrub range, read the stated light requirement as a flowering requirement, not a survival one.

What not to do

Do not plant sun lovers and hope. Lavender, olives, kangaroo paw, succulents and most grey leaved plants are built for high light. In shade they stretch, thin out, stop flowering, then rot at the base over a wet winter. Feeding does not fix it.

Do not try to grow lawn under a tree. Turf needs more light than almost anything else in the garden, and re-turfing the same patch is money into a hole. Mulch or a dry shade planting serves better.

Do not water shallowly and often to make up for a rain shadow. That keeps roots near the surface, where they dry out fastest. Water deeply and less often, and run a dripper along any bed under eaves or a dense canopy.

Do not cut through a tree's major roots, and do not tip a deep layer of new soil over the root zone. The first destabilises the tree and opens it to decay, the second suffocates it. Plant into the gaps between large roots, and mulch on the surface rather than burying organic matter.

Do not buy the largest pot size for dry shade either. In root filled ground a 140mm or 200mm plant settles faster than an advanced specimen, with less root mass to keep alive.

Trees that cast shade are the other half of the problem

Everything above is about plants that tolerate shade. The reverse question, which tree to plant to cast shade over a hot western wall, is a different job: canopy density, root behaviour near paving, and how much of the year you want it. Our guide to Australian native trees for shade covers it.

Where to start

Work out which of the three shades you have, fix the water problem before the plant problem, and plant in autumn or early spring. Trial three or five plants in the difficult section before committing the whole bed. Build the list from shop all plants.

Every order ships farm-direct with flat $99 delivery in QLD, NSW, VIC, SA, ACT and WA, a $399 minimum order, and the 30-Day Healthy Plant Guarantee.