x Halimiocistus

( hal - im - ee - oh - SISS - tuss )

At-A-Glance Information

This group of hybrid evergreen shrubs native to Portugal and France need full sun and little to no water, making them great candidates for inclusion in water-wise gardens. They are dense mound-forming plants that are crosses between Cistus salviifolius and Halimium, valued for their handsome foliage, profuse blooms, and high tolerance for both sun and heat. These are great in rock gardens, on dry banks, and for spilling over walls. 

x halimiocistus Species and Varietals

This hybrid genus of plants is a member of the Cistaceae. The ideal growing zones for x Halimiocistus are 4-24. To find your zone, click here: Zone Map.

Halimiocistus sahucii
This species reaches 2 feet tall and 3-4 feet wide, with narrow leaves in dark green. White flowers bloom profusely in springtime, and have a central puff of yellow stamens.

​Halimiocistus wintonensis
Reaching 2 feet tall and 4-5 feet wide, this species has furry, greyish-green leaves and produces white flowers with a central band of purple-red. Bloom comes in spring and early summer. Variety 'Merrist Wood Cream' have a red central band and yellow-cream colored petals.

Caring for and pruning x halimiocistus shrubs

Plant these shrubs in poor, well-draining soil in full sun. Established plants need little to no water, but do need some protection from frost and high, drying winds. After flowers fade, deadhead the plant and prune to form an attractive shape. Otherwise, these plants are very easy to care for and do not require much attention or fertilization. After a few years, these plants will become a bit leggy and unattractive; pruning can solve this issue as a stop-gap, but the plant will eventually have to be replaced. Continually taking and rooting cuttings will provide you with new plants when you need them (see the Propagation section below for more information).

Propagation

x Halimiocistus can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your shrub, follow the instructions below:

Propagating x Halimiocistus by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating x Halimiocistus by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds. The seed pods on Caesalpinia plants are pretty easy to spot, they're large and dangle from the branches, left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
  3. Caesalpinia seeds have a hard coating that protects them, but this coating also makes it a little difficult to get them to germinate. We can help the process along by scarifying them with sandpaper (or simply rubbing them against an abrasive surface). Do this with as many seeds as you can; they will probably not all sow, and the ones that do will be of varying characteristics. The more seeds you plant, the more chances you will have to get the resulting shrub you want. Place your seeds in lukewarm water for six hours. Viable seeds will sink to the bottom, and non-viable seeds will float to the top. You can discard any seeds that float.
  4. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  5. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Problems and Pests

These hybrid plants have few pests and issues.
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Gallery

Use these flowering shrubs to spill over rock walls and climb between stones in rock gardens.
Halimiocistus x wintonensis ‘Merrist Wood Cream’.
These shrubs are at home in cottage gardens, amongst other low-water plants.

Videos

A drought-tolerant garden featuring many Rock Rose varieties.

Resources

x Halimiocistus Growing Guide
Halimiocistus - Xera Plants
Wikispecies: x Halimiocistus
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 351, x Halimiocistus
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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