Roses have a reputation for being demanding, and most of it comes from advice written for a northern hemisphere calendar. In Australia the pruning month is different, the disease pressure is different, and modern landscape roses ask for a fraction of the work an old hybrid tea did. Get the position, the winter prune and the watering right and a rose will flower for eight months of the year.
Quick facts
| Detail | What to expect |
|---|---|
| Botanical name | Rosa species, hybrids and cultivars |
| Mature size | 0.5m for groundcover types, 1m to 1.5m for bush roses, 3m to 6m for climbers |
| Position | Six hours of direct sun minimum, morning sun preferred, open air movement |
| Soil | Deep, well-drained loam enriched with compost; pH 6.0 to 6.5 |
| Water | 20 to 30 litres per bush, weekly in summer, at the base |
| Flowering | October to May, with repeat flushes every six to eight weeks |
| Climate zones | All of Australia; best in temperate Melbourne, Adelaide and Perth, disease-resistant types in humid Brisbane |
Choosing the right rose
Rose types differ more than colours do, so decide the form before you fall for a flower.
Floribundas carry clusters of flowers on a 1 to 1.5m bush and give the longest display. Iceberg is still the benchmark, flowering almost continuously from October to May, though in humid districts it needs open air movement to stay clean.
Landscape and groundcover roses are the low-maintenance option and the right answer for most modern gardens. The Knock Out and Drift families were bred for disease resistance and need no deadheading. Red Knock Out makes a 1 to 1.2m shrub that flowers in waves all season, while Sweet Drift stays around 45 to 60cm high and a metre wide. Zepeti is a compact 50 to 60cm bush that performs unusually well in a pot.
Climbers need a structure and a plan. Rosa banksiae ‘Lutea’ is the thornless banksia rose, almost disease free and extremely vigorous to 6m or more, flowering once in a spectacular spring flush on old wood. It is right for a big pergola and wrong for a small fence.
How to plant
Bare-rooted roses are available from June to August and are the cheapest way to buy. Potted roses can go in year round, though autumn and winter establish best.
Choose the sunniest, most open spot you have. Roses tolerate heat far better than stagnant humid air, so morning sun and a breeze beat a sheltered corner every time. Dig a hole 400mm deep and twice the width of the roots, and work through a generous barrow of compost plus aged manure. Our guide to preparing soil for planting covers the fundamentals.
Soak bare-rooted plants for one to two hours before planting. Build a cone of soil in the base of the hole and spread the roots over it. Set the bud union, the knobbly graft point, at or slightly above soil level in warm humid areas so it does not rot, and 20 to 30mm below the surface in frost-prone inland gardens. Backfill, firm gently, water in thoroughly, then mulch 50 to 75mm deep with lucerne or sugarcane, kept 100mm clear of the stems. Space bush roses 60 to 90cm apart, climbers 1.5 to 2m.
Ongoing care
Watering
Roses are deep rooted and want deep watering. One soak of 20 to 30 litres per established bush, weekly in summer and twice weekly in a heatwave, beats daily sprinkling. Water at the base in the early morning. Evening overhead watering leaves foliage wet overnight, which is the easiest way to invite black spot. Potted roses need water almost daily in summer.
Feeding
Roses are hungry. Feed three times a season: after the winter prune, after the first spring flush finishes in late November, and again in February to push the autumn display. Use a complete rose fertiliser or a controlled-release product such as Osmocote for roses and camellias, and add sulphate of potash if flower size disappoints. Stop feeding by early autumn in cold districts. Our explainer on how fertilisers work is worth reading first.
Pruning
The main prune happens in winter. July is the standard month across most of Australia; June suits Brisbane and the warm subtropics, and late July into August suits the cold tablelands, where pruning too early risks new growth being frosted.
Remove dead, diseased and spindly canes first, then any crossing through the centre, aiming for an open vase shape that lets air move through the bush. Reduce the remaining canes by a third to a half, cutting 5mm above an outward-facing bud. Bush roses in warm humid climates benefit from a second, lighter trim around February, which sets up a strong autumn flush. Climbers are pruned after their spring flush; tie the main canes as close to horizontal as the structure allows, because that triggers flowering side shoots along their length. Never prune a banksia rose in winter, since that is the flowering wood.
Deadhead through the season by cutting back to the first five-leaflet leaf below the spent bloom. Knock Out and Drift roses are self-cleaning and do not need it.
Common problems and fixes
Black spot. Circular black blotches with feathered edges, followed by yellowing and leaf drop, worst in warm wet weather. Rake up and bin fallen leaves rather than composting them, water at the base only, thin the bush for airflow, and spray with a registered fungicide at the first sign.
Powdery mildew. A white dusty coating on new growth and buds after warm days and cool humid nights. Improve air movement, avoid heavy nitrogen feeding, and treat with a registered fungicide.
Aphids. Dense clusters on soft new shoots in spring. Hose them off or squash them by hand; ladybirds and hoverflies clean up the rest within a fortnight if you avoid broad-spectrum sprays.
Two-spotted mite. Fine pale stippling and faint webbing on leaf undersides in hot dry weather. Hose the undersides regularly and keep plants well watered, since mite outbreaks follow water stress.
Rose scale. Crusty white and grey encrustations on older canes. Scrub off with a soft brush and apply horticultural oil during the winter prune, when the bush is bare.
Distorted, streaked flowers. Thrips, most noticeable on pale varieties. Remove affected blooms; the damage is cosmetic. Our guide to identifying and treating common plant pests covers the identification steps.
Frequently asked questions
When should I prune roses in Australia?
Winter, while the plant is dormant or semi-dormant. July is the reliable month for most of the country. Prune in June in Brisbane and other warm subtropical gardens, and delay until late July or August in frost-prone inland districts so the new growth that follows is not burnt. Climbers are the exception and are pruned after their spring flowering.
Can roses grow in Brisbane and the tropics?
Yes, but variety choice matters enormously. Humidity drives black spot, so choose disease-resistant landscape types such as the Knock Out and Drift ranges over traditional hybrid teas. Plant in the most open, breezy position available, water only at the base, and prune twice a year rather than once.
How much sun do roses actually need?
Six hours of direct sun is the practical minimum, and morning sun is worth more than afternoon sun because it dries the foliage early and reduces fungal disease. Under six hours you will get a leggy plant with sparse flowers and more disease, no matter how well you feed it.
Why is my rose not flowering?
The four usual causes are insufficient sun, too much nitrogen from lawn fertiliser drifting into the bed, no winter prune, or suckers from the rootstock below the graft taking over. Check the base for shoots with different foliage and tear them off at the point of origin rather than cutting them.
Do roses grow well in pots?
Compact and groundcover varieties do. Use a pot at least 400mm across and 400mm deep, a premium potting mix, and expect to water daily through summer and feed every six weeks during the growing season. Large hybrid teas and climbers are poor pot subjects because their root systems are too vigorous to be contained.
Ready to plant?
Winter is the moment to buy, plant and prune, so a rose put in now will be flowering by October. Browse the full rose collection to compare bush, groundcover and climbing forms, or explore flowering plants for colour for companions that carry the bed between flushes.
