Two plants look good together when they are both healthy, and they are both healthy when they want the same conditions. That is the first rule of pairing plants. After it come the design rules: contrast the foliage, layer the heights and repeat a short list of plants. This guide covers each, with combinations that work in Australian gardens.
The rule that matters most: pair by conditions
The first test is whether two plants can share the same bed, the same watering and the same feeding.
| Group | Plants that combine |
|---|---|
| Hot, dry, no irrigation | Olive, agave, yucca, pigface, blue chalksticks, rosemary, dragon tree |
| Australian natives, low phosphorus | Grevillea, banksia, callistemon, westringia, lomandra, dianella |
| Subtropical shade | Xanadu, cordyline, bird's nest fern, clivia, native ginger, palm lily |
| Acid loving, moist | Camellia, gardenia, azalea, hydrangea, blueberry |
| Wet or poorly drained | Melaleuca, callistemon, Lomandra hystrix, Carex, Louisiana iris |
The combination that kills plants
Do not plant native plants that are sensitive to phosphorus in the same bed as heavy feeding exotics. Grevilleas, banksias and hakeas are damaged by the phosphorus in ordinary fertiliser, so a bed holding both a grevillea and a rose cannot be fed correctly for either. Keep native beds separate, and keep lawn fertiliser out of them.
In the same way, do not mix acid lovers such as gardenias and camellias with plants that want lime. Soil pH cannot be managed two ways in one bed.
Contrast foliage, not just flowers
Flowers come and go, and a heatwave can strip a display in an afternoon. Foliage is there every day, so the combinations that carry a garden are foliage combinations.
- Contrast leaf shape. Broad and glossy (xanadu, bird's nest fern) against strappy (lomandra, dianella) against fine (westringia, casuarina).
- Contrast texture. The soft, weeping foliage of Cousin It beside the hard outline of an agave.
- Use silver to separate greens. Olive, westringia, Silver Falls and blue chalksticks break up a bed that would otherwise read as one green mass.
- Use dark foliage as a foil. A dark cordyline or a Diamonds in the Dark crepe myrtle makes the green around it look brighter.
Layer by height
A canopy tree, a layer of shrubs, and groundcover beneath. This is how bushland is built, and it is what makes a garden look established. It has a practical benefit as well: layered planting shades the soil, keeps roots cooler and saves water through summer.
Repeat, do not collect
The most common mistake in home gardens is one of everything. Three or five of the same plant repeated through a bed reads as design; fifteen different plants reads as a collection. Repetition also simplifies the care, since there are fewer sets of needs to remember.
Combinations that work here
- Dry and architectural. Olive underplanted with Silver Falls and pigface, with agave repeated through gravel.
- Subtropical courtyard. Foxtail palm above, xanadu and cordyline in the middle, mondo grass or native violet beneath.
- Native and full of birds. Callistemon and grevillea over lomandra and dianella, with a prostrate grevillea spilling forward.
- Coastal. Pandanus as the feature, westringia clipped loosely, pigface trailing over the edge.
- Shaded southern wall. Tree fern above, clivia and liriope beneath, star jasmine on wires behind.
- Sunny and scented. Lavender and rosemary share full sun and dry, well drained soil. Lavender is the classic partner for roses too, planted on the dry, sunny edge of the rose bed, since roses want more water and feeding than lavender does.
Colour, briefly
- Choose two or three flower colours and repeat them.
- Hot reds, oranges and golds hold up in strong sun; pale colours suit shade and dusk.
- Stagger flowering times so each season has one plant at its best.
Common questions
What is the first rule of pairing plants?
Match the growing conditions. Plants that want the same sun, soil, water and feeding can share a bed; plants that do not, cannot.
Can I plant natives and roses together?
Not in the same bed if the natives are grevilleas, banksias or hakeas, because the fertiliser roses need damages them.
How many different plants should a garden bed have?
Fewer than you think. Three to five kinds, each repeated, looks more designed than a dozen single plants.
