Seasonal garden jobs by climate zone

A gardening calendar is only useful if it is written for your climate. The same month means opposite things in Darwin and Hobart: April is the start of the planting season in one and the last chance before winter in the other. Choose your zone below and the list changes accordingly.

Why the calendar changes by zone

Southern gardens run on temperature and frost. The year is bounded by the last frost in spring and the first frost in autumn, and almost every decision — when tender seedlings go out, when roses are pruned, when tender growth is cut back — hangs off those two dates. In the cool zone the window between them may be only five or six months, which is why so many crops are started indoors.

The tropical north runs on rainfall instead. There is no frost anywhere in the zone, and temperature varies remarkably little through the year. What varies is water: a wet season of roughly November to April, and a dry season from May to October, with a punishing build-up in between. Planting happens in the early dry, when soil moisture is still present and roots have months to establish before the next wet.

Between the two extremes, the subtropics and the arid interior each have their own logic. Subtropical gardens are limited by summer humidity rather than cold, so autumn is the strong planting window and winter is the productive vegetable season. Arid gardens are limited by how long soil moisture lasts, so autumn planting is close to compulsory: it gives six months of root growth before the next summer, and anything planted later meets that summer under-prepared.

How to use the list

Select your zone, then work down the current month. Tick jobs as you complete them; the ticks are saved in this browser on this device and nowhere else, so the list is still marked when you come back next week. Clearing your browser's site data removes them, and the clear button resets everything. There are no deadlines, no scores and no reminders — a job left unticked is not a failure, it is a job that did not need doing in your garden this year.

Treat the months as approximate. Seasons move by two to six weeks between the warm and cool ends of any zone, and by more between years. If your district is consistently later than the list suggests, read each month as the one after. Your own observations from two or three seasons are worth more than any published calendar, including this one.

Reading the seasons rather than the dates

Every month heading on this page is shorthand for a condition, and the condition is what actually matters. “March: plant shrubs and small trees” is shorthand for “plant once daytime maximums have dropped but soil is still warm”. In a warm year that condition arrives in April; in a cool one it may arrive in late February. The gardeners who get the best results are reading the garden, not the calendar.

Four signals are worth learning to read. Soil temperature decides germination and root growth, and it lags air temperature by several weeks in both directions — which is why beans sown on the first warm spring afternoon rot instead of sprouting. Day length drives flowering and bolting in many vegetables regardless of how mild the weather is, which is why lettuce sown in November runs to seed faster than lettuce sown in March at the same temperature. Soil moisture at depth, not at the surface, tells you whether a plant is actually short of water; push a screwdriver in before reaching for the hose. New growth on established shrubs tells you the plant has resumed active growth and can be fed or pruned.

None of these require equipment. A hand pushed into a bed to the wrist tells you soil temperature well enough to decide whether to sow, and the difference between cold and workable is obvious once you have felt both.

The jobs that matter most

If you only do a handful of things a year, these are the ones with the highest return.

Plant in autumn. In four of the five zones, autumn is the best planting window by a wide margin: soil is still warm, rain is more reliable, and roots establish through the cooler months while top growth is slow. In the tropics the equivalent is the early dry season. A shrub planted in autumn enters its first summer with six to nine months of root growth behind it; the same shrub planted in spring enters it with three.

Mulch before the dry months, not after. Mulch applied to moist soil holds that moisture. Mulch applied to soil that has already dried out keeps it dry, because it also intercepts light rain. In temperate, cool and arid gardens that means October, before summer. In the tropics it means the end of the dry, before the storms, and again at the start of the dry.

Prune at the right point in the flowering cycle. Spring-flowering shrubs and climbers set next year's buds on the growth made immediately after they finish flowering. Prune them then, and never in winter. Summer-flowering plants are pruned in late winter before growth starts. Getting this wrong does not damage the plant; it simply removes a whole season of flowers, which is why it goes unnoticed for years.

Deep-water anything planted in the last two years. This is the job that quietly decides whether a planting succeeds. Two long soaks a week through summer, tapering after the second year, produce a deep root system. Daily sprinkling produces a shallow one.

Weed while weeds are small. Ten minutes a week through the growing season replaces a day of work later and stops seed setting. This matters most in the subtropics and the tropical wet, where a weed can go from seedling to seed in a fortnight.

Jobs that are worth skipping

Some routine tasks do more harm than good, and the seasonal lists deliberately leave them out.

Cutting back frost damage in mid-winter. Blackened growth insulates the live tissue beneath it. Removing it in June or July exposes what you were trying to protect to the coldest weeks still to come. Wait until the last frosts have passed, then cut back to healthy wood.

Feeding a dormant lawn. A warm-season lawn that has gone straw-coloured in winter is dormant, not hungry. Fertiliser applied then does nothing except run off. Wait for soil temperature to rise and growth to resume.

Digging heavy soil when it is wet. Clay worked while saturated smears and sets, and the structural damage takes years to undo. There is a narrow window when clay is just moist, and that is the only time to work it. The same applies to walking on saturated beds and lawns.

Watering established low-water natives through summer. After the second summer they do not need it, and consistently wet soil around the root crown in warm weather is how most established Grevillea, Correa, Eremophila and Banksia are actually lost.

Planting in mid-summer. There is almost no situation in an Australian garden where this is the right decision. Wait for autumn.

Keeping your own record

The most useful gardening document you will ever own is a page of dates in your own handwriting. Note the date of the last frost you actually observe, the week the first real heat arrives, when each shrub starts and finishes flowering, and which beds dried out first. After two or three seasons you have a calendar calibrated to your block rather than to your region, and it will beat any general guide including this one.

Note the failures too, and the conditions around them. A shrub that died in its second February probably ran out of water, and a shrub that died in its second August probably drowned. Those two records are worth more than a shelf of books.

Seasonal job list

Select your climate zone. The list below changes to match it.