Calluna

( kal - LEW - nuh)

At-A-Glance Information

This genus of evergreen shrubs is commonly called Scotch Heather, Heather, or Ling. They are native to hillsides, moors and bogs In Iceland, Europe, the Faroe Islands, and the Azores. Varieties range from groundcovers to shrubs that reach a few feet tall. They require full sun and regular water, and most flower in mid- to late-summer, but some varieties bloom into late fall. Foliage can change colors come winter, providing year-round interest. Grow Calluna in mixed beds beds or borders, in pollinator gardens, or in containers.

Calluna Species and Varietals

Calluna vulgaris is the only species in the Calluna genus, which is a member of the plant family Ericaceae. Scotch Heather grows best in USDA hardiness zones 4 to 6 or Sunset growing zones 1A, 2-6 and 15-17. To find your zone, click here: Zone Map.

'Alicia'
Grows to 12 inches high and 18 inches wide; masses of white blooms late summer to fall.

'Anette'
Erect, up to 1 foot tall and 16 inches wide. Medium-green foliage and pink buds into the fall.

'Aphrodite'
To 15 inches tall and 2 feet wide, with red blooms in summertime.

'Firefly'
Upright habit, grows to 1.5 feet tall and 20 inches wide. Foliage is salmon-red in summer, bright red in winter. Mauve flowers.

'Kinlochruel'
Compact grower, to 10 inches high and 16 inches wide. Bright green foliage and white double flowers.

'Mrs. Ronald Grey'
Groundcover variety, 3 inches high and 20 inches wide. Purple flowers in mid-to late summer.

'Robert Chapman'
Spreading habit; 10 inches high and 2 feet wide. Greenish to reddish-orange foliage and mauve flowers.

'Sandy'
Grows to 15 inches tall and 2 feet wide, white blooms in late summer through fall.

'Silver Knight'
Upright habit, grows to 16 inches tall and 20 inches wide. Gray foliage turns purple-grey in winter. Lavender blooms.

'Spring Torch'
Spreading habit, up to 1 foot tall and 20 inches wide. Red-tipped green leaves with pink flowers.

'Tib'
Bushy shrub with a rounded look, grows to 1 foot high and 15 inches wide. Medium-green leaves and rosy purple double flowers.

Caring for Calluna

Calluna, or Heather, is typically grown from seed (either started indoors or direct-sown), but can also be purchased from a reputable nursery. Plant Heathers in a space in the landscape that receives full sun; ideally, they appreciate between 6 and 8 hours of sun each day for the best blooms. When these flowers are grown in less light, they will not flower as profusely. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 5.5 and 6.5 (slightly acidic). They grow very well in sandy or gravelly soils. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water newly planted Heathers regularly as they establish a strong root system in their new home. At maturity, they like to get regular waterings; as a general rule of thumb, water whenever the top inch or two of soil feels dry to the touch.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants and encourage reblooms. An annual pruning in the beginning of springtime is suggested for mature Scotch Heather shrubs; they can become a little leggy if left to their own devices. Calluna shrubs are long-lived perennials, persisting for upwards of 30-40 years in the landscape if cared for properly.

Propagation

Scotch Heather 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 Calluna, follow the instructions below:

Propagating Calluna by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, a clear plastic bag, a rubber band, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In summer, 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 4-6 inch portion(s) of the end of a green (not woody), non-blooming branch and strip off the bottom half of the leaves. 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.
Moisten with water, and ensure that the pot has good drainage. Place the plastic bag over your pot and secure it around the top of the pot with a rubber band. Your pot should be kept indoors in indirect 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 on your propagated Heather, you'll know you have roots.
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.

Propagating Calluna by Seed

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 heat-resistant tray (a cookie sheet will do), an oven (or smoker, if you have one), a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds in the middle of October through the end of November. Cut the seed heads from the plant; you'll know they're ready when they have turned brown and begun to open and spill their seeds. There should be about 10-15 seeds per seed capsule. Harvest as many as you can, and place all of them on a heat-resistant tray (a baking sheet will do). Place your tray in your oven at 250 degrees for about 30 seconds (or your smoker on low setting for two hours). Your seeds will probably not all sow, and the ones that do will be of varying characteristics, especially with hybrid-variety seeds, so the more seeds you prep and sow, the better chance you will have to get the resulting plant you want. This heating step is important; in the wild Heather seeds germinate best after wildfire activity, and this step mimics that natural habitat.
Place your seeds on top of your planting medium and lightly cover the seeds with a dusting of planting medium. Keep the soil moist but not wet by spraying it 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 14-21 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.
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, when you can transplant it to its new home, either outdoors or inside as a house plant. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new plant.