How to Grow Rock Cress Flowers

About Growing Rock Cress Plants in Your Home Flower Garden

Got a Rock Garden? Then, perennial Rock Cress plants are for you. Rock Cress flowers are native to rocky areas in the Mediterranean and Southern Europe. They were just too attractive to keep in one small area of the world. So today, you find it growing all over the U.S., and in other parts of the world, too. Growing Rock Cress is about as easy as it gets. They thrive in the slightly alkaline environment of rocky areas where other flowering plants struggle to survive. And, the plants do not need a lot of water or fertilizer. As a result, they are perfect as ground cover in many areas unsuitable for other plants.

Rock Cress produces a profusion of fragrant blooms in the spring. Colors are available in shades of white, pink, rose, mauve, and lavender. And Butterflies are attracted to the nectar-laden blooms.

Where to place these plants:

Rock Cress find themselves at home in rock gardens, borders, edgings, and as ground cover. They are good for hills and slopes, where is it difficult to grow grass or other plants. They also look good in flowerpots and windowsill planters.

Did you Know? The leaves and flowers of Rock Cress are edible, cooked, or raw. Not surprisingly, it has a pungent, cress-like flavor.

Rock Cress Flower Plant Specifications

Flower Colors: Shades of lavender, mauve, pink, purple, rose, mauve, and white.

Flowers Bloom: Spring.

Plant Height: Four to eight inches tall. Most Rock Cress plants grow six inches tall.

Ideal Soil pH: 5.5 – 7.0.

Hardiness Zones: 4 – 9

Light Needs: Bright, full sunlight. Partial sunlight in warmer regions.

Toxicity: Non-toxic.

Deer Resistant? Yes. The plants are resistant to deer, rabbits, and other foraging animals.

Number of Species: 120

Native To: Egypt, Greece, India, Persia, and Syria.

Plant Type: Perennial

Botanical Name: Aubrieta Deltoidea

Are Rock Cress Plants Edible?

NO!!

While Rock Cress plants are considered non-toxic. they are also considered non-edible. We found no recipes that use this plant. Nor, did we find any source to suggest it is consumed in any form. So, just enjoy this plant for its beauty.

Important Note: Contact with this plant can cause skin irritation. So, we suggest you wear gloves when handling it. And, wash your hands after coming in contact with it.

Medicinal Uses for Rock Cress Plants

Rock Cress plants are high in minerals, vitamins, and antioxidants. As a result, these plants are used in a variety of folk medicine and home remedies. Here are some of the uses:

It promotes cardiovascular health.
It boosts immunity.
Use it as an aid to digestion.

Light Needs

For healthy plants and prolific blooms, the plants require full, direct sunlight. Plant them in a location where they will receive at least six to eight hours of bright, full sunlight. Too little sunlight can also leave them susceptible to plant disease.

Perennial Rock Cress Plant Propagation

The plants are grown from seeds. They can be directly seeded into your flower garden, or seeded indoors for transplanting later.

For outdoor starts, sow Rock Cress seeds early in the season and cover lightly with 1/8″ of fine garden or potting soil.

The seeds have a long germination period, requiring two to three weeks. Sow seeds 6 to 8 weeks before transplanting seedlings outdoors.

Note: For indoor starts, we recommend a heated germination mat, to increase the speed of seed germination. Also, the germination rate is higher.

Keep soil moist during seed germination.

Established plants can be propagated by the division of the rootballs.

Ideal plant spacing is 15″ -18″. The plants spread out to form a loose mat, filling in the space between plants.

Days to Germination: 14 – 21 days.

About Seed Germination

How to Grow Rock Cress Flower Plants

Growing Rock Cress plants is easy. Grow the plants in full sun. However, the plants will tolerate light or partial shade.

Soil and fertilizer needs:

The plants will do well in fair to poor, rocky soils, with a neutral to slightly alkaline pH. Sandy, loam, or clay soil is fine. It should be loose, well-draining.

Add a general-purpose, high-nitrogen fertilizer when first planting, to help them to get a good start. Add a high-phosphorous fertilizer just before blooming. Like with other plants, Phosphorous promotes blooms.

Weed around the plants while they are young. This allows them to grow strong and healthy as they don’t have to compete with weeds for sunlight and nutrients.

Add mulch around the plants (if you can) to help retain sol moisture and to keep the weeds down.

Water requirements:

The plants like slightly dry soil. Water only during the hottest, driest period of summer.

You need to have patience when first growing Rock Cress. The plants bloom in the spring of the second year after planting, and every year afterward. However, they are worth the wait!

Prune plant and remove dead flowers after blooms have died, to give the plant a clean, healthy look, and to promote new plant growth. See more on Deadheading Spent Blooms.

Perennial Rock Cress are good reseeders. Allow some of the late flowers to die back and develop seeds. Also, you can harvest some of the seeds to replant Rock Cress in another location. Or, perhaps your gardening friends will want some of the seeds.

Rock Cress plants are hardy and will survive light frosts before going dormant for the winter months.

Pruning Perennial Rock Cress

Use pruning shears to remove any dead, damaged, or diseased leaves and stems. If the stems get leggy, cut them back. This encourages new growth, and results in a better-looking, bushy plant. Only remove newer stem growth. Cutting into older, woody stems can affect the development of new stems and flowers.

After the first set of blooms have died off, cut the spent blooms back. This encourages more blooms to form.

More on Deadheading Spent Flower Blooms.

How to Grow Rock Cress Flowers in Containers and Flowerpots

Their low growing habit makes Rock Cress flowers a good, if not frequent, candidate for flowerpots, and windowsill planters. Just place them in a sunny spot on your patio or deck and watch them grow!

Like any container-grown plant, they need a little more care and attention. In addition to normal plant care, here’s how to grow perennial Rock Cress flowers in containers:

Select a sunny to mostly sunny location on your deck.
It is important to have a drain hole in the container to allow excess water to drain from the pot.
Keep an eye on the moisture level. Check the plants every few days, especially in extended periods of hot, dry weather.
Let the soil dry out between watering.
When watering the plants, thoroughly wet the soil. Excess water will drain through the hole in the bottom of the flowerpot.
Nutrients in a flowerpot are limited. So, use fertilizer spikes to feed the plants. Or, apply a light solution of liquid fertilizer once a month.

Insects and Plant Disease

Rock Cress flowers are seldom bothered by insects or disease. Aphid and flea beetle infestations can occur. Apply insecticide or fungicide only if needed.

Also see: Plant Problems – Identify the causes and find the cures.

Overwintering Perennial Rock Cress Plants

Rock Cress plants are winter hardy. They do not require extra protection in most areas of the country. In colder regions, apply a layer of mulch around the plants. However, do not cover mulch on top of the plants. This can cause the plant to rot.