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Physical description: Gray rockcress is an herbaceous perennial which
is low-growing and tufted mat-forming; the habit can reach 6
to 12 in. tall and spread 18 in. wide. Leaves are evergreen,
alternate, dentate, colored grayish green, covered with a soft
white pubescence, and reach 1 in. long and ½ inch wide.
The flowers, which are white with an attractive fragrance, have
4 petals--each petal being ½ in. long and are at the top
of 6- to 8-in.-long stems. The flowering occurs in early to mid
spring. The fruit is a non-ornamental long silique.
Optimal growing conditions: Gray rockcress performs in full sun (or partial
shade in warm places) in fertile and very well drained soil.
This species is moderately drought and soil tolerant and does
well in lightly acidic to alkaline soil. Gray rockcress prefers
places with cold winters. In good conditions the rate of growth
is moderate. Winter hardiness: Zones 4-10, but in zones higher
than 7, heat and humidity may cause problems for the foliage,
which can show reduced vigor.
Susceptibility to pests and diseases: When planted in a poorly drained soil, Gray rockcress
may have diseases like crown rot, leaf spot, white rust, and
mildew. Concerning pests, soil mealybugs and aphids may do some
damage, but are not particularly threatening.
Use:
Gray rockcress is particularly valuable in rock gardens, on dry
stonewalls, or in borders, but can be used in many places as
a ground cover, especially in small areas. Foliage, flowers and
fragrance are valuable.
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