Species Purple Cress
white flowers with yellow-green stamens and center, green stems and leaves

Purple Cress

Cardamine douglassii

Also Known As - Limestone Bittercress
Purple Cress (Cardamine douglassii) is a native perennial wildflower found growing in moist woods and rocky open forest areas in central to eastern regions of the United States. It has elongated stems, and asymmetrical petal-like blue-violet flowers that bloom between April and June. Its leaves are basal and trifoliate, and they turn from purple to green in the summer. Once established, Purple Cress forms colonies in shaded areas and is easy to grow. This species is a good choice for naturalizing or in natural rock gardens where it provides attractive ground cover.

Watering:

Average

Propagation:

Seed Propagation,Division,Cutting

Hardiness Zone:

Sun:

full sun

Leaf:

Yes

Leaf Color:

green,purple

Growth Rate:

Low

Drought Tolerant:

Yes

Salt Tolerant:

Yes

watering

Purple Cress should be watered moderately, allowing the soil to dry out in between watering. During the growing season, water the plant every 7 to 10 days or when the top 2 inches of soil are dry. During cooler temperatures in fall and winter, water the plant every 10 to 15 days. Be sure to water at the base of the plant, avoiding wetting the foliage, as disease can be caused with poor air circulation.

sunlight

Purple Cress (Cardamine douglassii) prefers full sunlight for about 6 to 8 hours per day for optimal growth. Sunlight intensity is also important, with more intense and direct sunlight needed in the warmer months from spring through summer. Sunlight should be limited during the cooler months, as too much can damage the plant. In the colder months, indirect sunlight from south or western exposures is recommended. Additionally, it is important that the soil never dries out completely, as this can limit the Purple Cress’s access to the light it needs.

pruning

Purple Cress should typically be pruned in the early spring, as soon as it begins actively growing. This plant does not generally need heavy pruning – it only requires minimal pruning in order to control its size and shape. Generally, only dead or damaged stems can be removed and shaping of the plant can be done. Prune lightly by removing no more than 1/3 of the stems so as not to disturb the plant’s natural growth pattern.