How to Grow Watercress Herb Plants

About Growing Watercress Plants in Your Herb Garden

Watercress plants are dark green, leafy vegetables with a zesty pepper-like taste. It is an aquatic-type plant and is related to the Nasturtium family. Watercress herbs are grown along creeks and streambeds. Additionally, you can grow them in a low, wet area of your garden, or in a hydroponic garden.

Watercress is technically a vegetable. However, it is basically used as an herb because of its aroma and its peppery taste.

Watercress produces small flowers all summer long.

Watercress is used in salads, and as a garnish. It should be harvested, just before use. You can keep it in the refrigerator for short periods.

Flowers Bloom: Two months after planting.

Flower Colors: Green, white.

Hardiness Zones: 5 – 9

Perennial, Nasturtium Officinalis

Medicinal and Culinary Uses

Medicinal Uses:

Watercress has been used for bladder and kidney problems.

Culinary Uses:

The peppery taste of Watercress livens up salads. They are also used as a garnish.

Watercress is rich in Vitamin A and C, and a variety of nutrients.

Nutritional Value

100 g of watercress contains approximately:

11 calories
1.3 g carbs
0 cholesterol
0.1 g fat
0.5 g fiber
2.3 g protein
41 mg sodium

Watercress Plant Growing Specifications

Flowers Bloom: Summer

Flower Colors: Most are white, but also cream, orange, red, and yellow.

Days to Harvest: 30 to 50 days, depending upon growing conditions.

Plant Height: Six to twelve inches tall. It spreads up to 24 inches wide..

Light Needs: Four or more hours of indirect light.

Ideal Soil pH: 6.5– 7.5.

Plant Hardiness Zones: 3 – 12.

Ideal Growing Temperature Range: This cool-weather plant grows best at 50 to 70° F.

Plant Type: Perennial. The plant can live two or more years.

Native To: Eurasia.

Botanical Name: Nasturtium officinale

Toxicity: It is harmful to pets.

How to Grow Herb Plants

Planting and Soil Needs

Watercress are cool-weather plants. This herb grows in rich soil along streambeds and creeks. Plants grow in rich, wet soil. Plants thrive in indirect sunlight.

The plant is grown from seed. Start plants indoors in rich seed starting soil. Keep soil moist at all times.

Transplant seedlings outdoors along slow-flowing creek beds, or in a low area of your garden.

Light Requirement

For optimal growth, Watercress plants require at least four hours of indirect sunlight. The plants grow in full sunlight as long as the weather is cool in your area. They tolerate partial shade, especially as protection from the hot rays of the midafternoon sun.

Fertilizer Needs

The plants are not heavy feeders. As a result, they do not require much fertilizer, if any at all. If you grow them in rich soil, then they likely will have all of the nutrients they need to thrive. However, if the plants look a little pale or yellow, apply a liquid fertilizer every two or four weeks.

Water Needs

As their name implies, Watercress plants need water, and plenty of it, to thrive. Maintain a wet soil at all times during the growing season. Check the soil moisture frequently.

While the plant grow best in wet soil, it does not fare well in overly waterlogged soil. As a result, the plants can suffer root rot.

Insect and Plant Disease Problems

Watercress plants are seldom bothered by insects or plant disease.

On occasion, aphids, scale insects, spider mites, slugs, and whiteflies may infest the plants. Use organic insecticides only as needed.

Leaf spots and scab diseases may occur. Treat the plants with an organic fungicide.

Avoid root rot by avoiding overly waterlogged soil.

Also see: Plant Problems – causes and cures

Harvesting Watercress

Harvest leaves and young stems before the flowers bloom, as it becomes too bitter and pungent to eat. Cut leaves, wash and dry them, and store them in the refrigerator.

The tiny fruits ripen about two months after the first flowers bloom. Then, they drop seeds shortly after. Of course, save some of the seeds for next year’s crop.