Nasturtium officinale
vegetableA semi-aquatic peppery green that grows wild in streams and is cultivated in shallow trays or near water features. One of the most nutritious salad greens available, with a distinctive spicy bite and crisp texture. The standard ingredient in French watercress salads, sandwiches, and as a garnish for steaks. Grows perennially in zones 3 to 10 with reliable moisture.
Sun
partial shade
Water
Every 1 days
Harvest
~50 days
Difficulty
medium
Lifecycle
perennial
Comes back every year
Spacing
6-8 in
Planting Depth
1/4 in or press cuttings into wet soil
Soil pH
6.5-7.5
Soil Type
Wet, gravel
Hardiness Zones
Zones 3 – 10
When to Fertilize
Very light balanced fertilizer once established; aquatic environment provides most nutrition
Fertilizer
Minimal or none; too much fertility produces rank-tasting leaves
Grow in consistently moist to wet soil or in shallow trays of water. A north-facing raised bed with frequent watering can work in the absence of a natural water feature. Start from cuttings pressed into wet soil or from seed. Prefers partial shade in warm climates to slow bolting. Harvest frequently to encourage new growth. Remove flower stalks immediately to prevent bitter flavor.
Direct sow
Apr 1
Projected first harvest
May 21
Good neighbors that attract beneficial insects or deter pests
Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide
Water spray; insecticidal soap; watercress aphids are usually controlled by the abundant natural predators near water
Diatomaceous earth around dry bed edges; beer traps; handpick at night
Yellow sticky traps; insecticidal soap; introduce parasitic wasps
Row cover; diatomaceous earth; strong water pressure dislodges beetles
Harvest tips 4 to 6 inches long regularly — the more you harvest the more the plant branches. Avoid harvesting more than one-third of the plant at once. Use immediately or store loosely wrapped in damp paper towels in the refrigerator for 2 to 3 days. Watercress wilts quickly after harvest. Best eaten raw in salads or as a garnish; brief cooking for soups is also excellent.
Ounce for ounce, one of the most nutrient-dense foods on earth per calorie. Very high in vitamins A, C, and K, calcium, iron, and iodine. Contains phenethyl isothiocyanate, a compound studied extensively for cancer-preventive properties. A study published in the CDC journal Preventing Chronic Disease (Di Noia, 2014) ranked watercress the single most nutrient-dense of 41 powerhouse fruits and vegetables, giving it a top score of 100.
For educational and informational purposes only — HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.