Rock Cress - El Paso County Extension - Colorado State University

Lush, Compact Rock Cress is a Spreading Star
By Diane Betts, Colorado Master Gardener
What is it: Rock Cress (Arabis )
Everything's coming up Rock Cress...along your walkways, between the crevices of boulders, on a
stone-stacked ledge. So the next time you think of rock gardens, think 'rock cress'. These charming
plants will hug your rocks like
rugs and reward you with bursts
of color for weeks.
Appearance: Rock Cress are
early spring perennials that grow
10 to 15 cm tall, are usually on
the hairy side and have a lobed
leaf 1 to 6 cm long. Their dwarf,
compact growing habit forms
mounds of dense velvet-like
foliage. The plants bear small
flowers that have four petals in
the shape of a cross. When in
bloom, the long-flowering tiny
flowers will completely cover the plant with colors ranging from white to magenta, deep violet purple,
or soft pink. Rock Cress attracts butterflies and other pollinators.
Use in Landscape: Rock Cress is a perennial member of the mustard family that spreads through
creeping stolons, or runners. This
can be especially advantageous if
your goal is to colonize an open
area: Start with just a few plants and
let nature take its course. Rock
Cress partner nicely with
Bugleweed, Dianthus, Basket of
Gold or spring flowering bulbs. It
is also a great choice for containers,
borders, and on slopes. The
creeping nature of the plant will
produce a nice cascading affect.
Be sure to cut Rock Cress back to
about half its size after flowering.
Sheer the plant back as flowers fade
to regain fresh growth and

compactness. If it is left untrimmed, it will become rangy in summer heat. However, DO NOT cut
back the foliage in autumn or early spring. This may prevent the plants from flowering. For additional
rock gardening tips and ideas, go to http://www.ext.colostate.edu/pubs/Garden/07401.html.
Cultivation: Rock Cress prefer well-drained soil that gets some sun but will tolerate hot, dry
conditions once established. They do best in areas of low humidity and cool summers. Protection from
midday sun is desirable.
Arabis Snow Cap (Arabis caucasica ) is a robust plant and probably one of the most popular
cultivars. Profuse white flowers form mounds that look like snow from the distance. A show-stopping
combination is to plant Snow Cap with blue hyacinths.
Arabis blepharophylla, also known as 'Spring Charm'. It's rose-purple flowers are a great choice for
rock gardens or containers.
Arabis compinkie bears rose-red flowers on 6-inch stems. It's a great 'hot' color to mix among your
pastels.
When you have questions, your Colorado State University Extension office has researchbased
answers. For answers to your horticultural questions, contact the Colorado Master
Gardener Help Desk at 520-7684 or email CSUmg2@elpasoco.com.
Extension Programs are available to all without discrimination.