Watercress

Growing in Pots, Balconies & Indoors

Watercress is unusual among these crops – it wants constant water, so it grows beautifully in a pot standing in a saucer or tray of water on a bright balcony or a sunny windowsill. The grower does not list it as a houseplant, but its love of moisture and bright light makes a water-filled tray one of the easiest ways to grow it at home.

Quick Details

• Container Size: A medium pot standing in a deep water tray or saucer
• Indoor Suitability: Not officially a houseplant, but of all these greens it takes best to a bright sill, because you grow it wet
• Best Spot: full sun; a bright sill or balcony with a constant water supply
• Soil & Drainage: Heavy, moisture-retentive organic mix; here you deliberately keep it wet, not free-draining
• Watering in Pots: Keep it constantly wet – stand the pot in water and refresh the tray often to stop it going stagnant

Indoors & On the Windowsill

• Houseplant note: The grower does not tick it as a houseplant, but grown wet on a bright sill it adapts more readily indoors than most of these greens.
• Windowsill growing: Stand a pot of moisture-retentive mix in a tray of clean water on the sunniest sill, and keep the water fresh to avoid stagnation and off-smells.
• Overwintering: A hardy perennial – it slows in cold but survives; indoors, a cool bright spot keeps it in leaf longer.

On a Balcony or Patio

• Light & water: Full sun and a constant reservoir of water; top up and refresh the tray often in heat so it does not turn foul.
• Practicalities: A pot sitting in water is heavy and can overflow – place it where standing water and spillage are not a problem.

Choosing the Pot, Soil & Long-Term Care

• Pot & water: Unlike most container plants, watercress likes to sit in water – use a pot in a deep saucer or tray and keep it topped up, changing the water regularly to keep it sweet. This is the one case where you do not skip the saucer.
• Mix: A heavy, moisture-retentive organic mix rather than a fast-draining one.
• Feeding: A little balanced feed in the water occasionally is plenty – do not overdo it or the water fouls.
• Long term: Refresh the mix and divide the clump each year; take cuttings, which root readily in water.

Bloom & Edible Flower Guide

Quick Details

• Bloom Season: Spring through autumn
• Time to First Bloom: Once established — as a perennial it flowers freely through the warmer months in its first or second season
• Flower Appearance: Small four-petalled white to greenish-white flowers borne in clusters
• Edibility: Edible — the flowers share the crisp, peppery taste of the leaves, though the greens turn stronger and more bitter once flowering begins

Detailed Blooming Overview

Watercress grows in and beside running water and, once settled, sends up clusters of small white cruciform flowers through the warm season. The blooms are edible and draw bees and hoverflies, though many growers pinch them out to keep the leaves mild and tender.

Flower Characteristics

• Small four-petalled (cruciform) white to greenish-white flowers in clusters.
• Followed by slender curved seed pods if left to mature.

Bloom Care & Thinning

• Managing the bloom: Pinch out flowering stems to keep the leaves mild and prolong the harvest; leaf flavor grows hot and bitter once the plant is in full flower.
• Pollination: Pollinated by bees and flies.

Bloom Health & Protection

• Aphids: Aphids can gather on flowering shoots above the waterline; a strong jet of water or a rinse usually clears them, with insecticidal soap for heavier infestations.