When to Plant Sweet Potato in Sydney, Warm Temperate Guide

Sow October to December. Right now in September it is out of season. The next sowing month is October.

Also called kumara.

This Sweet Potato guide is written for the Warm Temperate zone, which takes in Sydney, Newcastle and Wollongong. Somewhere else? Your postcode picks the right one.

Not your zone? Cairns Brisbane Melbourne Canberra Alice Springs Perth

Also handy: will it frost this week? and what grows in shade.

Sweet Potato

Photo: Wikimedia Commons

Sweet potatoes are a warm-season, frost-tender crop grown from vine cuttings (slips), not seed. They are highly productive in warm Australian climates, with a single plant producing 2-5 kg of tubers. Beauregard (orange flesh) dominates Australian production. Tropical and subtropical zones are ideal; temperate growers need warm microclimates and season-extension techniques.

Planting Calendar for Warm Temperate

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
- - - - - - - - - D D D

S = Seed Tray   T = Transplant   D = Direct Sow

Want a nudge when it is Sweet Potato sowing time in Sydney?

One email a week with what is worth planting in the Warm Temperate zone right now, Sweet Potato included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.

How to Grow Sweet Potato in Warm Temperate Australia

When to Plant

Plant October-December once soil has warmed above 18C. Harvest March-May. Season is shorter than tropics but still viable.

Soil
Well-drained, loose, sandy loam. Avoid heavy clay or waterlogged soil. Do not over-fertilise. Rich soil produces excessive vine growth at the expense of tubers. Slightly raised mounds or ridges improve drainage and warming.
pH Range
5.5-6.5
Sunlight
Full sun (minimum 6-8 hours). Heat-loving crop. The more warmth the better.
Spacing
35cm apart, 100cm between rows
Watering
Water regularly during establishment (first 3-4 weeks). Once vines are growing strongly, reduce watering. Sweet potatoes are surprisingly drought-tolerant once established. Excessive watering encourag

Companion plants: Beans, Corn, Sunflower

Avoid planting near: No significant antagonisms, but vines will smother nearby low-growing crops

Warm Temperate Growing Tips for Sweet Potato

Recommended Varieties

  • Beauregard
  • Northern Star
  • Evangeline

Key Challenges

  • Shorter warm season limits tuber size
  • Cool autumn may prevent full maturity
  • Establishing slips in marginal soil warmth

Pro Tips

  • Warm the soil with black plastic mulch 2 weeks before planting
  • Start slips indoors from August to have rooted slips ready for October planting
  • Choose a north-facing, sheltered position for maximum heat

Harvesting Sweet Potato

When ready: Foliage begins to yellow (4-5 months after planting). Leaves may show autumn colour change. Scratch soil near a plant to check tuber size. In frost-prone areas, harvest before first frost as frost kills vines and can damage tubers.

How to harvest: Cut back vines first. Use a garden fork inserted 30-40cm from the plant base to loosen soil. Lift very carefully. Sweet potato skin is thin and damages easily, and wounds lead to storage rot. Sort into damaged (use immediately) and undamaged (for curing and storage). Do NOT wash before curing.

Worth growing?

A 2.4 m × 1.2 m bed fits 6 plants, about $40 worth at today’s Aldi and Woolworths prices, checked today.

That is roughly 9 kg at $4.44 a kilo.

Draw your sweet potato bed → No account needed.

Where to next

What sweet potato costs in the shops right now, retailer by retailer, updated daily.

Also worth sowing in the warm temperate zone this September: Ginger, Beetroot, Chilli Peppers and Cucumber.

The pest most likely to find your sweet potato: Rats and Mice.

Supermarket Price

Current average retail: $4.44/kg (12-month range: $2.99–$4.90)

Grow your own and save on grocery bills.

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Common Questions About Sweet Potato

When do you plant sweet potato in Australia?

It depends on your climate zone, not the calendar month alone. Planting months by zone:

Does sweet potato grow all year round in Sydney?

No. In the Warm Temperate zone the planting months are Oct to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.

What else is sweet potato called?

Sweet potato is the usual Australian name. Overseas seed packets and recipes call it kumara. Same plant, same growing advice.

Which zone am I in?

Type your postcode into the box under the heading and the page tells you, and links this crop in your own zone if it differs. Or look it up on the grow zone map. This page is the Warm Temperate zone, Sydney is its reference city.