Willow Myrtle Agonis flexuosa nana

Nana is the dwarf, mounded form of the Western Australian peppermint tree, holding the same narrow, softly weeping foliage on a compact rounded shrub instead of the large tree the species becomes. Crush a leaf between your fingers and you get the peppermint scent that gives it the common name. Small white flowers scatter through the foliage in the warmer months, but the plant earns its place on texture: massed on a slope or run along a driveway it reads as a soft, fine layer that moves in any breeze.

Massing it in sand, and the cut it will not recover from

Full sun to light shade both work, water needs are low to moderate once established, and growth is moderate, so a low hedge closes over within a couple of seasons. Free draining ground is essential and coastal wind is no problem, which makes it useful on sandy sites where softer border plants fail. Heavy waterlogged clay is a poor match, and young plants are tender to hard frost, so hold off planting in cold inland gardens until spring. Space it around sixty to eighty centimetres apart for a low hedge or a mass planting, closer if you want the mounds to knit quickly. The failure mode is the hard renovation cut. Agonis does not reshoot reliably from bare old wood, so a plant that has been allowed to grow leggy and is then cut back hard into brown stems often stays brown, and the only fix is replacement. Trim little and often from the start and the problem never arises. It is also worth siting it where the mounds have room to spread sideways, since crowding them against a path leads straight back to the hard cut you are trying to avoid.

Dwarf form, tree form, or a bolder shape

Buying the wrong one of these two is a common and costly mistake in a small courtyard. Agonis flexuosa is the full sized tree with a trunk, a shade canopy and roots to match, and it will overwhelm a courtyard that wanted a shrub. Nana stays at knee to hip height, works as a border, a low hedge or ground cover on a bank, and never needs a chainsaw. If you want a single bold statement in that same dry, gravelly setting rather than a soft mass, Spear Lily is the plant to look at, and the two combine well: fine weeping texture at ground level with one sculptural rosette rising out of it. Both sit in the natives range.

Little and often with the shears

Tip prune after the flowers finish in late spring, taking the lightest cut that keeps the mound dense, and repeat through the warm months if you are holding a formal edge. Always stay in green growth. Shearing a hedge over the top is fine so long as the blades never reach into bare stems. Feed in early spring with a controlled release fertiliser formulated for natives, water it in, and mulch between plants until the mounds meet. Established plantings need very little beyond an annual trim and a top up of mulch, which is most of the reason it gets specified for low care coastal gardens.

Choosing a size

This plant is available in 4 sizes, from 130mm up to 5L, priced from $16.95 to $29.95 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. These are younger plants, priced for planting in quantity, and they establish quickly once in the ground. Not sure which to choose? Read our guide to Australian native trees.