Aethionema

( eeth - ee - oh - NEE - muh )

At-A-Glance Information

Commonly referred to as Stonecress, this herbaceous, perennial (sometimes annual) flowering shrublet needs full sun and little to moderate amounts of water. Their spring to early summer flowers and foliage are both fragrant. Native to the Mediterranean and Asia Minor, these small shrubby flowers are attractive in bloom (in spring and summer) as well as in their dormant stages. They form woody bases that are herbaceous at the tips. Stonecresses are great plants in cold climates and in rock gardens, and their blooms can be extended even longer if the plant is deadheaded regularly. Plant stonecress in mixed beds, containers, or in cracks in rock walls or steps.

Aethionema Species and Varietals

Aethionema is a genus of approximately 60 species included in the family Brassicaceae, and derives its name from an Ancient Greek word meaning 'to light up, kindle'. The common name 'Stonecress' refers to its creeping habit and preference for stony, rocky planting sites. They are relatives of plants like Mustard and Cabbage. Aethionema grows best in zones 1-9 and 14-21. For more growing information, see the species descriptions below. To find your zone, click here: Zone Map.

Aethionema armenum (Rock Cress, Stonecress, Persian Candytuft)
This low-grower is native to the Mediterranean and found on rocky, sloped areas. Leaves are blue-green and the plant reaches around 4 inches tall at maturity. Flowers can be white or pink and bloom in mid-spring through early summertime.

Aethionema grandiflorum (Persian Candytuft, Persian Stonecress)
These limestone-rich soil loving plants are native to Turkey, the southern Caucasus, and northern Iran. This species is gorgeous in gardens, and has pink to lilac flowers that bloom in springtime. Evergreen.

Aethionema retsina
This critically endangered species is native to, and found only in, Greece. It prefers Mediterranean climates and rocky hills and shorelines amongst shrubby vegetation.

Aethionema saxatile (Burnt Candytuft)
This species is native to the European Alps, and prefers environments that are rocky and dry.

Aethionema schistosum
Grows 5-10 inches tall and 1 foot wide. This plant has an erect habit, and unbranched stems that hold dense growths of slate-blue leaves. Fragrant flowers are rose-colored. 

Aethionema 'Warley Rose' (Aethionema x warleyense)
This is a neat, compact grower to 8 inches tall and wide. Leaves are blue-green and grow on stems that hold dense blooms of pink flowers. Very commonly grown species, especially great when grown in warmer climates. This species lends its existence to Ellen Willmott, and is named after her garden at Warley Place. 

Caring for Aethionema

Choosing the correct placement in your yard is the first step in caring for your Stonecress. It will need to receive full sun, and enjoys light, porous, sandy soil with considerable lime content. If you would like to create the perfect soil conditions for these plants, combine one part compost with two parts sand, with a little limestone added to regulate for the correct pH. After they have been planted, these flowering beauties need to be watered relatively regularly for best performance. These are short-lived plants in most situations, and will need to be replaced after about two years, but they can self-sow (if the conditions are right) or be propagated for a more permanent showing in your garden. Spent blooms can be deadheaded to encourage further flowering, but other than this, the plant does not need much pruning. In springtime, when new growth is starting, the areas of the plant that have faded over wintertime will be apparent, and can be trimmed off. These plants do not need fertilizing if they receive the correct soil. 

Propagation

Stonecress can be propagated best in two ways: by seed or by cutting. If you are looking to create an exact replica of your plant, you will want to use the cutting method of propagation, as propagation by seed does not guarantee a clone of the parent plant.

Propagating Aethionema by Seed
To propagate via seed, gather the following materials: a bag, a pot (or planting tray), soil that is one part compost, two parts sand with a little limestone added in, and a spray bottle with water. Follow these directions to propagate your Stonecress from seed:
  1. In late summer, leave some of flowers on your existing plant and allow them to come to seed. Remove the seed pod cluster after it has dried, turned brown and some of the seed pods have begun to open and release their contents. Harvest the seeds from the seed pods and place them in a bag. This plant can self-sow if the conditions are right, but to ensure a new plant from seed, it is best to sow indoors in wintertime. Store your harvested seeds in a cool, dark place until about 10-12 weeks before the last frost of spring in your area. 
  2. Prepare your pots or seed trays with your potting mix and water to ensure drainage is occurring. Plant more seeds than you want new plants, as not all seeds will germinate. Place your seeds on top of the soil and cover with more potting mix. Water. Place your seed pots or trays in an indoor area that stays around 60 degrees Fahrenheit and receives bright indirect light, or place them in a greenhouse.
  3. The seeds will take between 30 and 90 days to germinate. After the danger of frost has passed in your area, you can transplant your new Stonecress outside in its garden location.

Propagating Aethionema by Cutting
​The best time to take cuttings from an existing plant is in spring or summer. To propagate by cutting, you'll need clean, sharpened garden shears, potting mix (one part compost, two parts sand and a little limestone added in), a pot (or pots, depending on how many cuttings you'll be taking), rooting hormone and a pencil. Once you've gathered your materials, follow these instructions:
  1. Choose an Aethionema plant to propagate. It should be a healthy plant, with new growth and should get some water the night before you take your cutting. Pick a healthy stem tip that has about three or four buds on it and make a 6-inch cutting. Cut quickly and evenly to take the healthiest cutting possible. 
  2. Add potting medium to your pot, and give it some water, ensuring that it has good drainage. Make a hole with your pencil in the medium, about two inches down. Dip your cutting in rooting hormone and place it in the hole. Fill in soil around it. Pat down just enough so the cutting stands up by itself. Give it some water. 
  3. Keep the soil around your plant somewhat moist as it grows, and ensure that it is in a place that gets bright indirect light and stays at a temperature of between 50-60 degrees Fahrenheit. Once the danger of frost has passed the next spring, you can transplant your cutting to its final home outdoors.
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​Pictured: Stonecress seed pods, just reaching the point when they are ready to be harvested.

Problems and Pests

Stonecress has few pests, including:
  • Spider Mites
  • Aphids
For information on how to eradicate and prevent these issues, see the links below:
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Gallery

These smaller shrublets are great for fronting borders.
Stonecress flowers are tiny and bloom in clusters.
Stonecress is an attractive plant even when not in bloom; and is great amongst rocks.

Videos

There are no Aethionema videos available at this time.

Resources

Wikipedia: Aethionema
How to Grow Aethonemia
Plant of the Week: Aethonemia
How to Grow Aethonemia Plants in Your Garden
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 136 - 137, Aethionema
If you have any questions, comments, concerns, or photos you’d like to add to the gallery, please let me know by sending me a message using the button below!
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