Watercress can be grown without planting it in a running stream. Although watercress tends to grow in moving water, it is not a growth requirement. Watercress is not considered a water plant because the shoots and leaves of the plant grow above the water. The plant prefers to take root in moist environments, but you can create the right conditions for growth with inexpensive items and a continual supply of water. If you can practice diligent watering your watercress will even tolerate soil.