Written by Susan – Plant Lover, Adelaide
Autumn in Adelaide is genuinely the best time to be in the garden. The heat has broken, the soil is still warm from summer, and the first rains are making an appearance. This is the season where the work you do now sets up your garden for the next twelve months.
Here's your April–May checklist for Adelaide gardens.
🌱 Planting: Do It Now
Autumn is the single best planting window in Adelaide — read our full guide on what to plant this autumn for detailed recommendations. In short:
🟢 Plant trees, hedges, and shrubs now — roots establish through winter with minimal watering.
🟢 Establish native groundcovers — they spread through winter and spring.
🟢 Plant bulbs (daffodils, tulips, jonquils) — Adelaide's cool winters are perfect for spring bulbs. Plant from April.
🟢 Get winter vegetables in the ground — broccoli, cauliflower, kale, silverbeet, and leafy greens all thrive in Adelaide winters.
✂️ Pruning: What to Prune (and What Not to Touch)
🟠 Roses: Light prune in April to tidy up. Major winter prune happens in June–July.
🟠 Hedges: Final light clip of the season in April to tidy up before winter. Don't do a hard prune heading into cold weather.
🟠 Deciduous trees: Wait until trees are fully dormant (June–July) before any structural pruning.
🟠 Summer-flowering shrubs: Prune lightly after flowering ends in autumn. Remove dead wood.
🔴 Don't prune: Natives that flowered in autumn — let them set seed for wildlife. Don't prune frost-sensitive plants heading into winter.
🌿 Feeding: The Autumn Feed
Autumn feeding is different from spring feeding — the goal is to strengthen root systems and harden plants for winter, not to push lots of lush new growth.
✅ Organic or low-nitrogen fertiliser: A potassium-rich fertiliser (higher K in the NPK ratio) promotes root and stem strength without pushing soft growth.
✅ Compost top-dress: A layer of compost around the base of trees and shrubs feeds soil biology and improves structure.
✅ Lawn fertiliser: A slow-release autumn lawn feed will carry your lawn through winter and set it up for a great spring recovery.
❌ Avoid high-nitrogen feeds: High nitrogen in autumn pushes lush soft growth that is vulnerable to cold snaps and pests.
💧 Watering: Transition to Winter Mode
🟢 Established plants: Reduce to once a week as temperatures drop. Let autumn rain do the work where possible.
🟢 New plantings: Continue 2 deep soaks per week until mid-May, then taper as winter rain arrives.
🟢 Check and adjust your irrigation timer: Many Adelaide gardeners forget to reduce their summer irrigation schedule in autumn — overwatering in winter is a common cause of root rot.
🍂 Garden Tidying
✅ Clear summer annuals and spent vegetables — compost healthy material, bin diseased plants.
✅ Top up mulch — 7–10cm across garden beds before winter. Mulch regulates soil temperature and suppresses winter weeds.
✅ Clean up leaf litter — especially around roses and plants prone to fungal issues.
✅ Divide overgrown perennials — autumn is a good time to split clumping plants like Agapanthus, Lomandra, and ornamental grasses.
✅ Check stakes and ties — inspect young trees before the winter wind season.
💚 Final Thoughts from Susan
"April and May are my favourite months to be in the Adelaide garden. The pressure of keeping things alive through summer is gone, the soil is in great condition, and everything you plant now will reward you massively in spring. If you're going to invest time in your garden, do it now."
If you're planning any new planting this autumn, browse our full range or get in touch — we'd love to help you choose the right plants for your space.
