Friday, July 13, 2007
Heath and Heather
Low-growing heath and heather are the perfect plants for rock gardens and perennial borders. The best news is that growing heath and heather is a snap. Both love sunny spots (a full day of sun is best, but a half day will do) and, with few exceptions, these plants thrive in acidic soil. They thrive especially well in coastal climates, where growing conditions are mild and moist. Heath and heather hail from Europe and South Africa, where they’ve naturalized to create breathtaking sweeps of color during peak bloom. You can choose heath and heather varieties to have flowers year-round, from the depths of winter to the heat of summer. Combined with evergreen shrubs and dwarf conifers, drought-tolerant heaths and heathers create an easy-care garden that's packed with eye-pleasing vistas, season after season. Calluna vulgaris, or "Scotch Heathers," begin blooming in mid-summer, and continue their display of purple, pink and white flowers (and every shade of the three) well into late autumn. The sprightly blooms aren't the only attraction these evergreen shrubs have to offer; many varieties' foliage colors and growth habits are intriguing. Erica carnea and Erica x Darleyensis varieties are known as the "Winter or Spring Heaths." They are more tolerant of somewhat alkaline soils than other varieties and can tolerate being planted in open shade. Buds formed during the summer months open into fabulous shades of pink and white during the coldest months of the year, offering color to snowy and bleak landscapes. Erica cinerea, or "Bell Heather," has needle-like foliage on erect stems. "Bell Heather" bears very bright, showy bell-shaped flowers in shades of magenta, purple and white from late spring on. Erica tetralix, "Cross-leaved Heath," bears flowers on the tips of branches in pendulous terminal clusters for most of the summer. These are very neat and compact plants. Erica vagans, "Cornish Heath," has glossy green foliage with a wide and spreading habit. Masses of bell-shaped flowers are born along the stems starting in July and lasting throughout the summer. Erica x watsonii, "Watson's Heath," is a natural hybrid of E. ciliaris and E. tetralix found in Truro, Cornwall England. It has similar characteristics as E. tetralix but is slightly hardier and flowers heavier and longer. Tips of new growth are brightly colored Choosing a site Soil requirements The success of any garden depends on proper soil preparation. Ideal soil for most heaths and heathers is slightly acidic, has excellent drainage and contains generous amounts of organic matter (such as wet peat moss, well-rotted compost, etc.) worked in to retain moisture. Heaths and heathers do not survive in a soil that is too fertile or wet; under these conditions, the plants will produce lush growth that may not harden to withstand the harsh winter cold. These plants require little maintenance once they are well established. Plant in raised beds if your soil is clay-based or if your site is flat. A sloping site facilitates drainage naturally. Light requirements Heath and heather need sun and open air circulation. A southern or southeastern exposure is best. A full day of sun is ideal; however, some species tolerate a half day of full, bright sun, especially ground cover varieties. Heaths and heathers especially need sun to show off their foliage colors and for heavy flowering. Each plant is labeled with all the information you need for placement in the garden. Location requirements Heath and heather need a site with good air movement or circulation. Heath and heather care tips WateringHeaths and heathers need thorough, deep watering 2 to 3 times per week, or when the soil feels dry to the depth of your first knuckle. They should not be allowed to completely dry out, nor should they have "wet feet." Because overwatering is detrimental to the health of heath and heather, first check the moisture content before each application of water. Also, water in the morning. Plants watered in the evening run a higher risk of fungal infection because foliage and soil remain wet over a longer period of time and damp conditions promote fungal growth. When watering, avoid wetting the foliage. A slow, deep soaking is best because it promotes root growth and supports existing foliage. During times of heavy rainfall, remove mulch temporarily to allow the site to drain and dry sufficiently. Once established, heaths and heathers are quite drought-resistant and will survive quite well during periods of hot, dry weather. However, remember to provide some supplemental water during long periods of dry weather. Fertilization Since heaths and heathers prefer a 'lean' soil, they do not require regular feeding -- as long as the soil is amended with organic matter. However, if you do choose to fertilize, use a good organic granular for ericaceous plants (azaleas, rhododendrons, holly, etc.). Scratch into the soil surface around each plant in early spring. Be careful not to over-fertilize and remember to avoid high-nitrogen fertilizers! Winter protectionYoung plants, or those in very exposed areas, can suffer from a combination of drying winter winds and sub-zero temperatures. To protect against these conditions, mulch around the plants to protect root zones and growth below the ground; or place evergreen boughs over the plants in a tent-like manner to act as a wind and sun break for the foliage above the ground. Pine needles, straw, or other light material can also be used to completely cover the plants after the ground is frozen. Pruning Young plants, during the first 4-5 years in the garden, need an annual pruning to promote dense branching. Pruning stimulates new growth and increases the amount of flowering branches. Prune summer-blooming varieties in early spring before the new growth resumes. Remove any dead wood and prune any branches that suffered winter injury, cutting back to green wood. Formation pruning -- pruning or training young plants into the shapes you want -- should be minimal, as the plants have a pleasing natural shape. With sharp pruning shears, cut back last year's flowering branches to a point below the old flowers. Avoid cutting into the mature wood. Remember that lush, new growth will start at the point where you cut, so don't be afraid to cut back to prevent legginess and to increase the density of the plant. Generally the winter blooming varieties, such as Erica carnea and E. x darleyensis, do not require regular pruning. Prune as necessary to keep in bounds and to remove any winter injury. This light pruning should be done after flowering. Remove spent blossoms as soon as they fade.