Watercress (Nasturtium officinale), is a rapidly growing aquatic or semi-aquatic perennial plant that prefers the coolers months. It is thought to be one of the oldest known leaf vegetables consumed by humans.
Preferring to be planted in shallow running water, the hollow stems of watercress will float and spread across the surface of the water. Cultivation of watercress in a small backyard garden pond, hydroponic or aquaponic system is practical and easily achievable.
Even if you don’t have moving water, such as a small stream, a waterfall, a bowl that overflows, or tiers in a fountain, you can still plant watercress into a floating basket. You won’t need to use any soil or gravel, as watercress loves having its roots exposed directly to the water where it can take up nutrients. You can also grow it in boggy soil during winter.
Being a semi-aquatic, watercress is well-suited to hydroponic and aquaponic cultivation, thriving best in water that is slightly alkaline. The demand for fresh watercress usually exceeds supply, partly because cress leaves are unsuitable in dried form. Watercress is sometimes sold in supermarkets in sealed plastic bags, but with a shelf life of only one or two days it is difficult to find fresh. As with all fresh herbs and vegetables, growing it at home is the best way to ensure you have a good supply of organically grown cress.
Watercress contains significant amounts of iron, calcium, iodine, manganese and folic acid, plus vitamins A, B-6, C, and K. Watercress is relatively rich in vitamin C and contains a significant amount of omega-3 fatty acids. The health benefits from eating watercress are extensive, so next time you have a spare moment, research it for yourself, you will be amazed and want to eat it all the time.
It’s the new leaves and stems of the watercress that are best harvested. Picking these leaves continually during the growing season will ensure strong, repetitive growth. If left unattended, it can reach heights of between 50cm and 1m. It will generally go to seed and flower in late spring. Once it flowers, the foliage will become quite bitter. The seed pods will form, drop into the water and start growing. You can harvest the seeds and use them as sprouts and the edible shoots can be harvested days after germination.
In some regions around the world watercress is considered a weed. If it is growing wild in the presence of manure it can be a home for parasites, such as liver fluke, so as with all edible water plants growing wild, be cautious about picking.
Watercress can be eaten raw or cooked. Here are a few of my favourite ways to enjoy it:
- Pick young tender leaves, wash thoroughly and toss into a mixed green salad. The cress will have a similar taste in a salad as rocket.
- It is a great way to add freshness to a bowl of vegetable soup. Just add a handful of raw watercress directly into the bowl of soup on serving.
- Handfuls of watercress leaves and stems are a great addition to any stir-fry.
- Heat a fry pan with a tiny amount of oil and a little garlic. Place several handfuls of watercress into the pan and toss in a capful of balsamic vinegar. Once it has wilted, serve immediately.
- Try this super easy, delicious soup recipe from Jamie Oliver; In a large saucepan, sauté potatoes, onions and garlic in olive oil. Add stock to make a soup and simmer until the potatoes are soft. Add chopped watercress and cook for 3–4 minutes. Liquidise the soup, and serve with a swirl of crème fraiche.
- If you are having a BBQ, a watercress salad is lovely with honey mustard dressing. It will really complement any meat.
- You can’t beat a watercress and egg sandwich, especially if the eggs and cress are from your own backyard!
So, why not give it a go this winter and grow some watercress, it is a great edible crop and looks lovely growing in a pond.
About the Author – Calinda Anderson
Calinda runs the Woodvale Fish and Lily Farm, established over 18 years ago and now a leader in the water gardening industry. The farm produces a fabulous display of water lilies, water plants and fish, and the friendly, knowledgable staff can always offer advice and assistance. Calinda is also passionate about aquaponics and enjoys sharing her knowledge with people wanting to learn more.
For more information, visit www.woodvalefishandlilyfarm.com.au