Sowing in September
What We're Sowing & Planting in September
The bees know it! The birds know it! Spring has arrived on Transition Farm.
September is one of the busiest months of our growing year. The greenhouse is filling with trays of seedlings, green manure crops are being incorporated into the soil, and thousands of young plants are preparing for life in the field.
If you're gardening in a cool to warm temperate climate, here's what we're sowing this month.
Prefer a quick reference? Download our free one-page September Sowing & Planting Guide.
Leafy Greens
September is one of our favourite months for leafy greens. Cool weather and increasing day length make it the perfect time to establish crops before the heat of summer arrives.
We're sowing:
- Buttercrunch Butter Lettuce
- Optima Butter Lettuce
- Pirat Butter Lettuce
- Red Iceberg Lettuce
- Head Cardinal Lettuce
- Reine d'Glace Lettuce
- Celery
- Spinach
- Silverbeet
- Agretti
- Orach
- Rocket
- Bok Choy
- Tatsoi
- Mizuna
- Mustards
Farm Tip
We always interplant Sweet Alyssum throughout our vegetable beds. It flowers for months and provides nectar for hoverflies, lacewings and tiny parasitic wasps that help keep aphids under control naturally.
Tomatoes
Although many gardeners rush to sow tomatoes, for field tomatoes, we deliberately wait until mid-late September.
Short, stocky seedlings transplant far better than tall, leggy ones and are perfectly timed for early-November planting.
Farm Tip
If you're feeling optimistic about the weather, take a punt and sow a small batch now, then another in three weeks. It spreads your risk, gives you a backup if late frosts strike, and if you end up with more seedlings than you need, they're always appreciated by friends, neighbours, schools and community gardens.
Explore our collection of Certified Organic - Biodynamic Heirloom and Open Pollinated Tomato Seeds
Capsicum, Eggplants & Chillies
These heat-loving crops are started August - October to produce abundant harvests through summer and autumn.
Explore our colourful collection of Capsicums, Chillies and Eggplant
Root Crops
Root crops love the warming soils of spring.
This month we're sowing:
- Carrots (every three weeks until March)
- Beetroot (every month)
- Celeriac
- Florence Fennel
- Radish
- Salad Turnips
Farm Tip
Instead of sowing one big crop, sow little and often. Succession sowing means you'll enjoy fresh harvests for months instead of having everything ready at once.
Explore our collection of Certified Organic/Biodynamic Root Crop seeds.
Brassicas
Now is the perfect time to transplant:
- Broccoli
- Cauliflower
- Cabbage
- Kale
Farm Tip
Every brassica is covered with insect netting immediately after planting.
Diamondback Moth doesn't just attack broccoli—it also loves rocket, radish, turnips, bok choy, mizuna and mustards, so we protect all of these crops.
Explore our collection of Certified Organic/Biodynamic Brassica seeds.
Onions & Leeks
Early September is our preferred time to sow long-day onions for large bulbs that store beautifully.
We're also:
- succession sowing Spring Onions until March (Long Tropea Onions too!)
- sowing Leeks from July through October
Explore our Certified Organic and Biodynamic Onion and Leek Seed
Herbs & Companion Plants
Before tomatoes head into the field we've already transplanted:
- Basil
- Marigolds
These flowering companions attract beneficial insects before the tomatoes arrive.
We're also sowing:
- Coriander (regularly through spring)
- Parsley (three sowings each season)
- Summer Savoury
Explore our Herb Collection
Zucchini, Cucumbers & Summer Squash
These are started in the greenhouse now and planted into the field during October.
Because our farm sits in a frost hollow, our first plantings receive protection from frost and cold winds.
We continue sowing throughout summer to reduce the impact of frost, disease and weather.
Explore our Zucchini, Cucumbers and Summer Squash Collection
Peas
September is our second sowing of:
- Sugar Snap Peas
- Snow Peas
- Shelling Peas
This gives us a steady harvest throughout spring and often fresh peas at Christmas.
Flowers
September is one of our biggest flower sowing months.
Cut Flowers
- Zinnias
- Celosia
- Cleome
- Phlox
- Cosmos
- Strawflower
- Salvias
- Scabiosa
Flowers for Beneficial Insects
- Sweet Alyssum
- Calendula
- Marigolds
- Dill
Favourite Fillers
- Beaded Cress
- Pennycress
- Mignonette
- Amaranth
- Celosia
Potatoes & Sweet Potatoes
September is when we begin producing our own sweet potato slips.
Potatoes, however, have to wait until early-October (because of frost threat).
Our farm sits in a frost hollow, so waiting a few extra weeks saves us from losing young shoots to late frosts.
Happy Spring!
Every September reminds us why we love growing from seed. The greenhouse is alive with new growth, biodynamic preparations are helping build healthy soils, and every tray of seedlings promises months of fresh harvests ahead.
Whether you're growing a few pots on a balcony or planting a large kitchen garden, we hope this guide inspires you to get sowing.
Keep this month's sowing list handy by downloading our free one-page September Sowing & Planting Guide. It's perfect for printing or saving to your phone while you're out in the garden.
