Considered to be one of the oldest leafy vegetables consumed by humans, watercress is a close cousin of mustard greens, kale, and arugula. Watercress offers many nutrients and health-promoting substances and can be used in salads, soups, sandwiches, and more to add a refreshing, tangy flavor. While it is considered an aquatic or semi-aquatic perennial that is often found near nearly standing water, you can also grow cress in containers indoors or anywhere outdoors as long as the location is shaded and has plenty of water.
Steps
Method 1 of 2: Growing Watercress in Containers
Step 1. Purchase watercress seeds
Seeds can be ordered online or at garden and nursery supply stores.
- Common varieties of cress include English Watercress and Broadleaf Watercress.
- You can also start with adult cress from a supermarket or farmer's market. Just soak the base of the stems in water for a couple of days to encourage root growth and plant them in the ground, as you would with seeds.
Step 2. Prepare the container for planting
Choose a large container or planter with drainage holes at least 6 inches deep. Add a layer of farm fabric to the bottom of the container to hold the topsoil when you water. Add pieces of broken pots or small pebbles to the base of the container to allow for good drainage.
- You can also use smaller containers and place them in a larger drainage tray.
- Plastic containers are recommended over terracotta ones, because this loses moisture too quickly for the watercress.
Step 3. Place a large drainage tray under the planting container to keep the plants well watered continuously
You can also place small pebbles in the drainage tray to allow water to flow freely into the grow container
Step 4. Fill the growing container with potting soil
Use a soilless blend that drains well and contains peat moss and perlite or vermiculite. Leave about 5 cm of space under the top edge of the container and water the soil well.
The ideal pH for the grow mix should be between 6.5 and 7.5
Step 5. Sow the watercress seeds
Place the seeds 0.64 cm deep in the growing mix, leaving 7.5 to 10 cm of space between each seed.
Step 6. Water abundantly
Soak the grow mix deep enough so that the water fills the drainage tray below about halfway, but doesn't go any higher than the grow container. Replace the water in the drain tray with fresh water every two to three days.
- To retain the soil, abundantly cover the surface with a thin, transparent plastic sheet that has small protruding holes, so that the water can be kept and at the same time the air flow is guaranteed. The sheet can be removed when the sprouts begin to appear above the ground.
- Mist the surface of the soil with water in a spray bottle every other day.
Step 7. Place the container in indirect sunlight
Place the cress where it will receive about six hours of natural light each day, but try to avoid excessive, direct rays that can burn young plants.
You can keep the containers indoors, or, when the temperature is constantly between 13˚ and 24˚C where you live, you can place the container outside during the hottest months
Step 8. Fertilize the watercress
Add a small amount of soluble fertilizer, generic for gardening, to the water in the drainage tray with the quantities suggested in the package.
Step 9. Collect the watercress
Once the plants have grown to about 12.5 - 15cm tall, use kitchen or gardening scissors to trim the top of the plant, about 10cm, as needed.
- Avoid harvesting more than a third by cutting each plant to allow them to keep enough foliage necessary to continue growing.
- Periodic harvesting helps encourage new growth.
Step 10. Wash the watercress
Wash the watercress in cold water, dry it and use it immediately or wrap it in bunches and refrigerate it for use within a few days.
Method 2 of 2: Growing Watercress Outdoors in the Ground
Step 1. You can also start growing from adult cress purchased in a supermarket or farmer's market
Just soak the base of the stems in water for a couple of days to encourage root growth, and then plant them in the ground, as you would from seeds.
Step 2. Choose a spot to plant
Watercress grows well in a cool location as long as it is sunny with partial shade. Planting cress on the surface of a stream or stream of fresh, fresh water is ideal, but you can also create your own puddle or water hole.
Ideal planting times are in early spring after the last frost, or early fall before temperatures drop
Step 3. Prepare the site for cultivation
If you have a steady flowing stream or stream, simply mix 10 to 15 cm of organic compost between the top 15 to 20 cm of soil from the surface.
Step 4. Create a grow site
If you do not have a source of water available, dig a hole about 60 cm wide and 35 cm deep to create a puddle. Line the bottom and sides with a large plastic sheet suitable for swimming pools, leaving a 6 '' lip at the top, and drill some holes in the sides for drainage. Fill the lined hole with an equal parts mixture of garden soil, coarse building sand, and compost, and add a handful of fertilizer.
Step 5. Water the grow site
If you plant next to a stream, make sure the soil is deeply soaked. If you have created a grow site, fill the pool to the brim with water.
If you've set up a grow site, water the area every two to three days to ensure it stays fully soaked or install a water pump to keep fresh water circulating in the pool
Step 6. Plant the cress
Sow the seeds about 6mm deep and about 12.5mm apart, and cover them with a thin layer of fine garden soil.
You can also start cress indoors using the method described above or transplant adult plants. However, as the plants can be delicate, they may be difficult to transplant
Step 7. Grow watercress
Once the cress has sprouted, thin out the seedlings so that there is a distance of 10 to 15 cm between them. If small white flowers appear, cut them with gardening scissors to encourage new growth.
Step 8. Collect the watercress
Once the plants have grown to about 13 - 15cm in height, use kitchen or gardening scissors to trim the top (about 10cm) of the plant as needed.
- Avoid harvesting more than a third of the entire plant when cutting to leave enough foliage needed to continue growing.
- Periodic harvesting helps encourage new growth.
Advice
- If whiteflies appear under cress leaves, brush them off periodically with soap and water.
- Eliminate snails and slugs by hand if they appear.
- Keep the area around the cress free of weeds and use a light mulch to retain moisture and block weeds.
Warnings
- If you grow watercress near a stream or stream, test the water to see if it is contaminated or contains dangerous pollutants.
- Wash the watercress well before consuming it to avoid eating the dirt or other pollutants.
- Avoid using insecticides, herbicides, and pesticides on or near the cress because they can be absorbed easily and can be harmful to humans who eat the plants.
