Brassicas - The Manual of Seed Saving - page 78

Watercress cultivated in a basin, Wildegg Castle, Switzerland
POLLINATION NOTES Watercress is an outcrosser.
PROPAGATION Watercress is an herbaceous perennial, hardy to zone 5. It grows to be 12-28 in.
(30-70 cm) tall, and its stalks develop runners that creep across the ground near water. It is best
propagated vegetatively by cuttings, with seed being useful only when vegetative propagation is not an
option. Sow seed in early summer in a very moist mix in containers; seeds germinate between 50°F
(10°C) and 59°F (15°C). When the plants have several leaves, the containers can be placed outdoors
near running water. When seedlings are 2 in. (5 cm) tall, they can be planted in a watery ditch. The tips
of the plants must stick out of the water, and the water surface level can then be slowly raised, in
stages.
White flowers appear at the tips of highly branched stalks in late spring, fruits in mid to late sum-
mer. Late summer/early autumn is the ideal planting time.
HARVEST Seedpods can be straight or curved like a sickle. Harvest when yellow ripe (after the milk-
ripe stage, slightly before fully ripe), dry further, then thresh.
SELECTION CHARACTERISTICS The many regional selections differentiate themselves mainly in the
intensity of their leaf color, from light to dark green. The brown form is a cross with Nasturtium mac-
rophyllum ; it is sterile and can only be propagated vegetatively.
DISEASES AND PESTS No significant diseases or pests affect watercress. A horticultural center in
Switzerland reports problems with a pest not typical in vegetable gardening: wild ducks, which flock
to creeks planted with watercress. Colorful plastic bird netting is stretched above the crop to protect it.
CULTIVATION HISTORY Watercress is found the world over, and its exact area of origin is unknown.
Its heyday was the 18th and 19th centuries, when it was grown on a relatively large scale in England,
France, and Germany as a leaf vegetable; special water beds were established to this end. It is now
grown in eastern Africa, southeast Asia, and other countries, mostly on a very small scale, as cultiva-
tion is labor-intensive.
SCURVYGRASS, SPOONWORT
Cochlearia officinalis
One common name comes from the plant's apparent ability to cure scurvy (it has a high vitamin C
content); it is also said to be effective in problems with the bladder and digestion. Another is a referen-
ce to the spoon-like shape of its spicy, cress-like leaves, which can be a pungent addition to salads.
Scurvygrass is found wild in salty, moist soils, growing along the coast of the Atlantic Ocean and the
Baltic Sea from northern Spain to Scandinavia.
WHAT YOU'LL NEED