This low-growing perennial adds color along walls, borders, and underneath spring-blooming bulbs.
Rock cress(Aubrieta deltoidea)is one of several plants going by the common name of rock cress.
Rock cress works exceptionally well along walls, borders, and underneathspring-blooming bulbsto add color to a garden.
The flowers of rock cress are borne so fully that you cannot see the foliage.
Where to Plant Rock Cress
Plant rock cress in well-draining soil.
It thrives inrock gardensand is attractive along walls and in borders.
Rock cress adds stunning contrast when planted under spring-flowering bulbs.
See more of the best plants for rock gardens here.
Press the seeds into the soil after the last frost of spring but don’t cover them.
They require light to germinate.
Theseeds can also be started indoorsfour to six weeks before the last frost.
Sowing seeds in a rock garden or on a vertical surface requires some special care.
Mist regularly but sparingly until germination occurs.
Rock Cress Care Tips
Rock cress plants require relatively little care after they are established.
Light
Rock cress thrives in full sun.
In less than full sun, the blossoms are not as bright or plentiful.
Due to its rocky upbringings, this plant prefers alkaline soil.
This plant is extremely drought-tolerant and grows well in a container.
Water it only when the soil is dry.
Temperature and Humidity
Rock cress grows best in warm temperatures between 65F and 70F.
In warmer zones, it benefits from some shade in the afternoon.
It grows well in low to mid-range humidity.
High humidity may shorten the length of the perennial’s life.
If you leave spent blossoms on rock cress, there is an excellent chance the plant will reseed.
Consider this a benefit because rock cress can be somewhat short-lived as a perennial.
Most commercial potting soils are neutral or slightly acidic.
Increase the pH if necessary by adding crushed egg shells, wood ashes, or baking soda.
Don’t overwater the plant; too much water will kill it.
In areas with warm, humid summers, rock cress may have a shorter life span.
Plant them in part-shade to increase their longevity.
How to Propagate Rock Cress
Gardeners can propagate rock cress by seed, clippings, or division.
Gardeners can harvest the seed from mature plants in the fallor do nothing.
Rock cress will self-seed with little encouragement required.
Cuttings:Take stem cuttingsfrom a mature rock cress plant in the spring.
Put the cutting in a pot filled with sterile potting soil or perlite, and water it well.
Place it in a warm, bright-light location and watch for new growth.
This semi-evergreen perennial grows up to 4 inches tall and forms an excellent groundcover.
It grows up to 4 inches tall.
Zones 4-9
‘Variegata’ Rock Cress
Aubrieta deltoidea’Variegata' has gray-green leaves with creamy margins.
It is available with blooms in several colors, including dark purple, violet-blue, pink or white.
It grows to 6 inches tall.
In warm, humid surroundings, they may not live that long.
Most varieties of rock cress bloom from late spring to early summer.
