How to grow Watercress in Australia
Watercress (Nasturtium officinale) is a fast, peppery leafy green that grows naturally in clean, shallow streams. You do not need a creek: it grows happily in a pot standing in a tray of water. Keep it constantly wet and shaded from hot sun, pick it often, and it regrows quickly from the cut stems.
📖 Our full guide: How to Grow Watercress in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | All year | |
| Northern Rivers NSW | All year | |
| Sydney & Coastal NSW | All year | |
| Melbourne & Victoria | All year | |
| Adelaide & SA | March to September | Sow Mar to Sep in a pot standing in a tray of water, in part shade. It fails in summer heat, so treat it as a cool season crop. |
| Perth & WA | March to September | Sow Mar to Sep in a pot standing in a tray of water, in part shade. It fails in summer heat, so treat it as a cool season crop. |
| Tasmania | September to March | Sow Sep to Mar in a damp shaded spot. Slows but survives winter. |
| Canberra & ACT | August to April | Sow Aug to Apr in a tub or a wet shaded spot. Midwinter sowing fails in freezing water and soil, but established plants sit through winter and regrow in spring. |
| North Queensland | May to August | Cool dry months only. Water stays too warm Nov to Apr for clean growth. |
| Darwin & Top End | May to August | Cool dry months only. Water stays too warm the rest of the year for clean growth. |
Not to be confused with: Nasturtium, the garden flower, which is a different plant (Tropaeolum) despite watercress's botanical name. Both have a peppery taste.
Where to plant
Watercress needs constant moisture and clean water. The simplest setup is a pot of good potting mix standing in a tray or saucer of water that you refresh every day or two. A shallow, clean, slowly flowing stream or a pond edge also works. Give it part shade; in hot weather, moving the trays into shade greatly extends the cropping season.
It grows best in cool to mild weather. Heat makes it bolt and warm, still water goes stale.
- South East Queensland, the Northern Rivers, Sydney and Melbourne: sow at any time of year, with shade in summer.
- Adelaide and Perth: sow from March to September in a pot standing in water, in part shade. It fails in summer heat.
- Hobart: sow from September to March in a damp, shaded spot. It slows but survives winter.
- Canberra: sow from August to April in a tub or wet, shaded spot. Established plants sit through winter and regrow in spring.
- North Queensland and Darwin: grow it only in the cool dry months, May to August, as the water stays too warm the rest of the year.
How to plant
- Fill a pot with drainage holes with quality potting mix and stand it in a tray of water so the mix stays wet.
- Sprinkle the fine seed on the surface and press it in lightly. Keep it moist; seedlings appear in about a week.
- Thin to about 15 to 20 cm apart, or leave small clumps.
- Or start from cuttings: stems from a bought bunch of watercress root at the nodes within days in a glass of water. Plant them once roots form.
Watering and feeding
Never let watercress dry out. Change or top up the water in the tray every day or two so it stays fresh. Stagnant, warm water turns slimy and can grow harmful organisms.
Feed lightly every week or two with a liquid vegetable and herb fertiliser for lush leaves. Do not let fertiliser build up in the tray water; flush it with fresh water often.
Pruning and care through the year
- Pinch and cut the tips often to keep the plant bushy and leafy.
- Pinch out flower buds as they appear. Flowering makes the leaves smaller and more bitter.
- Move pots into the shade on hot days, and replace tired plants with fresh cuttings every few months.
Harvesting
Start cutting when the plants are about 10 to 15 cm tall, from about six to eight weeks after sowing. Snip leafy stems above the water or soil with scissors, before flowering, and it regrows quickly.
Watercress is best eaten fresh. Picked stems keep up to about four days in the fridge standing in a glass of water.
Growing in pots
Watercress is ideal for pots. Use a pot at least 20 to 30 cm wide and deep, stand it in a tray of water and refresh the water often. Keep it in part shade.
Using it
Use watercress raw in salads and sandwiches, blend it into soups and sauces, or wilt it into stir-fries at the last minute. Its peppery bite pairs well with eggs, potatoes, fish and steak.
Do not pick wild watercress from streams or drains, especially in grazing country, as the water can carry liver fluke and other contamination. Grow your own in clean water.
Propagation
Watercress roots readily from stem cuttings. Stand 10 cm pieces in a glass of water; roots form at the leaf nodes within days. It can also be grown from seed sown on the surface of wet potting mix.
Companion planting
Watercress shares a damp, shady spot with other plants that like constant moisture.
Good companions
Pests and diseases
Watercress has few pests, but snails and slugs love the damp conditions it grows in.
Pests to watch for
- Snails Ragged holes in leaves and slime trails.
- Slugs Chewed stems and leaves overnight.
- Aphids Clusters on soft shoot tips in warm weather.
Diseases to watch for
- Leaf spot Small brown spots on the leaves. Remove affected stems.
- Downy mildew Yellow patches on top of leaves with grey fuzz underneath in cool, damp weather.
Common questions
Can I grow watercress without running water?
Yes. Grow it in a pot of potting mix standing in a tray of water, and change or top up the water every day or two so it stays fresh. Keep it in part shade.
How do I grow watercress from cuttings?
Stand stems from a bought bunch in a glass of water. They root at the leaf nodes within days. Plant them in wet potting mix once roots have formed.
Is it safe to eat wild watercress?
It is not recommended. Watercress picked from streams and drains, especially in grazing country, can carry liver fluke and other contamination. Grow your own in clean water.
Why is my watercress going to seed?
Heat and long days make watercress flower. Keep it in shade, keep the water fresh and cool, pinch off flower buds, and grow it in the cooler months in hot regions.
Is watercress the same as nasturtium?
No. Watercress's botanical name is Nasturtium officinale, but the garden nasturtium is a different plant, Tropaeolum. Both have a peppery taste.
How long does watercress take to grow?
From seed, you can start cutting in about six to eight weeks. Rooted cuttings are ready sooner. It regrows quickly after each cut.
Sources we checked: Yates: How to grow watercress; Gardening Australia: FAQs, growing watercress; Gardening Australia: Propagating basil and watercress; RHS: Nasturtium officinale (watercress).