The short version: September is the month to scatter herb seed straight onto a warm bed or a wide pot, rather than fussing with trays. Coriander, dill, parsley and chives can go in now across most of Australia, while basil waits until mid to late September in temperate gardens and stays undercover longer in cool districts. Sow what you actually cook with, and a small effort now can keep the kitchen picking through summer.
Herbs have a reputation for being fussy, and for needing a bed of their own before they will do anything useful. It is a myth, and September quietly disproves it. Most culinary herbs are small, quick and forgiving. They want warm soil, sun, and a gardener who walks past often enough to pick them.
September is the month you can put the trays away
By September the soil in most Australian gardens has warmed enough that herb seed can go straight onto the bed where it will grow. Rake a patch smooth, scatter the seed across it, cover it lightly, water it in, and keep the surface just moist until the seed is up.
Scatter sowing suits herbs because most are content growing close together in a loose drift. Coriander, dill, chives and parsley all take it well, and you thin as you pick, so the first thinning and the first small harvest are the same job.
Cool mornings also keep a scattered bed from baking dry, which a hot November will not.
Sow the herbs you actually cook with
The most useful herb patch is the one that matches your dinners, not the one that looks complete. Four herbs you reach for every week beat a dozen you admire and never touch.
So start at the chopping board. If coriander ends up in most things, give it a generous drift. If your household gets through parsley fastest, hand parsley the biggest share, then browse herb seeds and fill the gaps once you see what runs out first.
Sow in two or three goes rather than one. A fortnight between sowings keeps the supply steady, the thinking behind our guide to beating the glut.
Basil, coriander and dill ask for a little timing
Three popular herbs come with a September rule each, and getting those right is most of the difference between an easy herb summer and a frustrating one.
Basil is genuinely cold sensitive and can suffer chilling damage well before any frost, below roughly 10°C. In temperate gardens, including Sydney, Melbourne, Adelaide and Perth, mid to late September is soon enough to move it outdoors, while cool and highland districts should keep it undercover longer. Basil seeds are cheap enough that a second sowing is no great loss.
Coriander and dill have the opposite problem. Both run to seed as the days lengthen and the heat arrives, so sowing coriander seed now rather than in high summer buys the longest leafy run. Expect it to bolt eventually regardless, because that is what coriander does.
Parsley and chives are the steady ones: slow to germinate, then reliable for months.
Tired perennials are worth replacing from seed
A thyme, oregano or sage plant that has gone woody and half bare is usually past its best, and September is a sensible month to raise its replacement from seed. Rosemary, lemon balm, chervil, tulsi, perilla and mint can be started now too. Mint is worth a pot of its own, since it will colonise a bed.
A note on feeding and flavour
Go easy with the fertiliser. Over-feeding herbs, particularly with nitrogen, pushes soft leafy growth and can reduce the essential oils that carry flavour and aroma. Research on basil has found lower nitrogen rates can lift essential oil content even while the plant makes less bulk. Compost and an occasional weak seaweed solution is usually enough, and lean growing tends to taste better than lush.
Pots, balconies and a sunny step
Herbs do not need a bed of their own. They need a spot you walk past. A wide, shallow pot on a balcony can carry a scattered sowing as well as garden soil, and it sits closer to the kitchen.
Choose the widest pot rather than the deepest, since most culinary herbs are shallow rooted. Free-draining mix, sun, shelter from wind and steady water is the whole recipe, though pots dry faster than beds as the weather warms.
Herbs to sow in September, zone by zone
Timing shifts with your climate. If you are unsure of your zone, the postcode finder on our what to sow now page will sort it out.
Cool (Hobart, Canberra, Ballarat, Armidale)
- Scatter chives, coriander, dill and parsley once the bed warms.
- Basil stays undercover until the nights lift.
Temperate (Sydney, Melbourne, Adelaide, Perth, Newcastle)
- Scatter borage, chives, coriander, dill and parsley through the month.
- Basil moves outside from mid to late September.
- In Perth, southern WA and Adelaide the dry summer starts early, so mulch and steady water matter more than feeding.
Subtropical (Brisbane, Gold Coast, Coffs Harbour)
- Basil, chives, dill and parsley can all go in now.
- Give parsley a spot that falls into part shade as the season heats up.
Tropical (Darwin, Cairns, Townsville)
- Basil is the standout sowing this month.
- Heat and humidity build from here, so afternoon shade helps.
Arid and semi-arid (Alice Springs, Broken Hill, Mildura, Kalgoorlie)
- Chives, dill and parsley can be scattered now, with coriander watched as days heat up.
- Basil is safer from mid September, once cold nights ease.
Frost is worth checking before basil goes outdoors. The Bureau of Meteorology potential frost days maps give a regional picture, and your local forecast covers the rest.
Herbs repay a small effort more generously than almost anything else in the garden. A packet of seed, a raked patch and ten minutes in September can keep a kitchen supplied for months. If you started trays last month, our guide on sowing in August for a summer full of herbs still applies to those seedlings, and the scattered sowings often catch up.
Frequently asked questions
Can I scatter herb seed straight onto the garden in September?
In most Australian gardens, yes. The soil has usually warmed enough for coriander, dill, chives and parsley to be scattered over a raked bed and lightly covered. Keep it just moist until seedlings appear.
Is September too late to sow coriander?
No, it is one of the better months. Coriander bolts as days lengthen and temperatures climb, so sowing now usually gives the longest run of leaf.
When can basil go outside?
In temperate gardens, mid to late September is usually early enough. Basil can be damaged below roughly 10°C, so cool and highland gardeners do better waiting. In the subtropics and tropics it goes straight out.
How big should a pot of herbs be?
Wider matters more than deeper, since most culinary herbs are shallow rooted. A broad, free-draining pot gives more surface to scatter across, and needs watering more often than a bed.
Is it worth replacing an old thyme or oregano plant?
Often, yes. Perennial herbs go woody and sparse after a few years, and a seed-raised replacement started now can be productive before the old plant is pulled.