A heather’s evergreen foliage changes and intensifies in hue during cooler temperatures. Height varies by cultivar. Shorter types are best-suited to be ground covers or planted in rock gardens; taller varieties can be grown in rows to form borders.
Light
Heather blooms best in full sun in zones 4 and 5. In zone 6, it will appreciate afternoon shade.
Soil
Heather requires well-drained soil and does well in sandy soils or rocky terrain. It thrives in peaty, more acidic bogs and moorlands. It does not need fertile soil, it can thrive in poor soils and can tolerate salt spray.
Water
Water the plants faithfully when young. This plant requires one inch of water per week. Once established, heather has average water needs in zone 4 but will require more irrigation in warmer zones.
Temperature and Humidity
Heather likes a climate that is moist and cool. Calluna is typically hardy in zones 5 to 7 but may thrive as far north as zone 3 with adequate winter protection or snow cover. It cannot tolerate high temperatures and humidity in the southern U.S.
Fertilizer
As long heather has some organic matter or peat moss in its soil, it does not need additional nutrients. Heather prefers acidic soil; you can give an acidifying nitrogen fertilizer made especially for acid-loving plants such as rhododendrons once a year in early spring. If you are going to give fertilizer, provide no more than one pound per 100 square feet and no later than August 1. Added any later, it will spur growth during the winter when the plant should be dormant. Excessive fertilization tends to cause leggy, spindly branches.
Types of Heather
The type of cultivar you choose depends on how you want the plant to function in your yard. Taller types form an oval mound, good for hedges; shorter types form a mat suitable for ground covers.
Calluna vulgaris ‘Firefly’: 20 inches; flower color begins as chartreuse turns to lilac, foliage is reddish-brown in summer and finishes as brick-red in winterCalluna vulgaris ‘Robert Chapman’: 8-18 inches high, greenish-yellow foliage in summer, changing to orange-red and reddish in winter. Rose-purple flowers in slender 20-25 cm long clusters in late summer.Calluna vulgaris ‘Wickwar Flame’: 23 inches; copper and orange-red foliage in winter, bright orange and yellow in summer, flowers mauve.Calluna vulgaris ‘Bonita’: 12 inches; pink to red buds on green stems in the summer, with the foliage taking on gold to orangey hues in the fall and winter. Calluna vulgaris ‘Kinlochruel’: 10 inches; double white flowers, bright green foliage that turns bronze in the winter
Pruning
Prune heather in early spring to encourage faster growth. Mature heather tends to become leggy, so pruning will keep it more compact, bushy, and more attractive.
Propagating Heather
Heather grown from seed will not reproduce true to the parent plant. The best way to propagate heather is by taking cuttings in the summer, rooting them indoors over the fall and winter, and planting them outdoors in the early spring.
How to Grow Heather From Seed
In its natural habitat, heather seeds germinate best after a wildfire. Mimic these conditions to spur germination in the spring or fall. For best results, you’ll need an oven or smoker, a pot or seed tray, vermiculite or soilless mix, and a water spray bottle. Here’s how to grow heather from seed.:
Potting and Repotting Heather
Plant heather in a large, wide pot, one size bigger than the previous one with good drainage holes in the bottom. Although it should not be too shallow, Heather does not need a deep planter. This plant can stay at the same depth as its nursery pot or only as deep as the plant’s root ball. It does well in clay pots.
Overwintering
Heather is a hardy plant. However, in zone 4 or northward, protect potted heathers by insulating the plant. Cover the pot with polystyrene foam (also from the bottom) and mulch the plant heavily with a layer of straw. Smaller pots can be taken indoors and grown under grow light or near a window with indirect sunlight.
Common Plant Diseases
Heather is susceptible to powdery mildew and root rot, which you can avoid. Powdery mildew does not kill heather, but this fungal disease can mar its appearance. It takes the form of a dusty-looking covering on a plant’s foliage. Its leaves are evergreen and develop attractive tones in fall and winter (bronze or purple tones). As it’s a foliage plant, powdery mildew can spoil one of the plant’s best features. To prevent powdery mildew, avoid overhead watering. Prune faithfully every spring to keep plants compact, thereby improving airflow. If powdery mildew affects your heather, use an off-the-shelf fungicide or a baking soda solution. Waterlogged soil is usually the culprit behind root rot, especially if the Phytophthora fungus is present. Phytophthora is rarely an issue in soil that drains well, reinforcing the need to provide your heather with sharply draining soil.
How to Get Heather to Bloom
Different varieties of heather flowers bloom from late July to November in the northern hemisphere. The bell-shaped flowers may turn brown but remain on the plants over winter. Heather has an herbaceous aroma with a light floral tone mixed with a heavy musky scent. You do not need to deadhead heather floral spikes, but you can clip them off with pruners to encourage new growth once they fade. To encourage heather to bloom, make sure the plant has well-draining acidic soil. Heather needs at least six hours of sun a day.
Common Problems With Heather
Heather is a hardy, easy-growing plant that is not susceptible to many issues beyond fungal growth as a result of overwatering.
Browning Foliage
If your heather plant’s foliage starts browning, touch the leaves to see if they’re dry and brittle—a sign that the plant is dying. Break off a single stem of the plant. If it’s pliable and green or white inside, it’s still alive; if it snaps in half easily, it is likely dying or dead. Usually, sudden death in the middle of the growing season is a sign of root rot. You’ll need to pull up the plant, dispose of it, and not plant heather in that same spot for a few years. If the plant still has signs of life, it might have drainage issues. Pull it up and inspect the root system. If the roots have turned dark brown or black, cut away the rot using sterilized scissors. Apply an antifungal and replant it in well-draining soil new soil in a new spot; this action may save the plant.
Leggy Stems
Heathers thrive in poor soil. A non-fertile soil encourages the roots to branch out in search of nutrients, which gives them deep, sturdy root systems. If the soil gets fertilizer, then the soil has too much nitrogen, resulting in weak root systems and excessive vegetative growth or longer stems. Also, if the plant is not getting enough light, stems may grow out in search of more sun. To prevent or reverse legginess, stop giving fertilizer and place the plant in a sunnier spot. You can also trim the leggy stems in spring or early fall to encourage healthy growth.
Distorted Leaves or Leaf Drop
If you notice your plant’s leaves turning yellow, stippling, or mottling, you might have a mite infestation. Carefully inspect the plant, overturning the leaves. Mites are hard to see. But, you might notice red or yellow dots or some webbing. A steady stream of water on the undersides of leaves for three days may be enough to eliminate the problem. Otherwise, use insecticidal soap or horticultural oil all over the plant. Check for small, hard oval-shaped bumps on the stems. These bumps may be scale insects that can cause leaf drop and distorted leaves. Scale insects can be picked off, and horticultural oil and insecticidal soap can also help control scale infestations.
