Crazy About Camellias
By Bob Chapman
Camellias are one of the most popular landscape shrubs and no wonder. These wonderful shrubs, with their deep green glossy leaves and the abundant amounts of flowers are a joy to behold. Once established, little care is needed. Camellias are excellent container plants, growing happily for years on the patio or porch. Camellias used as hedges will really enhance the landscape. They serve nicely as focal points when in bloom.
History
Camellias are members of the tea family (Theaceae). Tea is made from the leaves of Thea sinensis (also called "Camellia Thea") and its varieties. Thea originally hails from the Asian areas of the world. Thea are sold as Camellia japonica, Camellia sasanqua and Camellia reticulate and literally hundreds of varieties of each are now listed and sold commercially. Most of us are familiar with the very popular Camellia japonica, with its wide array of flowers ranging from white to pink to reds, with bicolors and shades in between.
Flower forms
Camellias feature six different and distinct flower forms.
Single form. This form has one row of petals (as many as eight) surrounding the stamens. Pictured is Camellia sasanqua ‘Apple Blossom.'
Semidouble. The flowers have two or more rows of petals (regular or irregular).Shown is Camellia hiemalis Shishi-Goshira.
Peony forms. These camellias look nearly ball-shaped, with petals in no particular pattern, somewhat resembling a powder-puff, but in the shape of the well-known peony.
Shown is the Camellia japonica ‘Debutante.'
Rose form double. These flowers feature multiple layers of petals regularly overlapping each other. Stamens are revealed when the flower is fully opened. The well-known Camellia japonica ‘Mathotiana' is a good example.
Formal double flowered. These forms feature multiple layers of petals and never show the stamens when open. The beautiful Camellia japonica ‘Alba Plena' typifies the form.
Anemone form. This blossom has one or more rows (layers) of petals, flat or undulating, surrounding a central mound of intermingled petaloids and stamens.
Growing camellias
Happily, these colorful shrubs, with their dark green leaves, are easy to grow. They prefer acidic soils, moderate watering and protection from the hot sun (but not complete shade). Camellias will withstand occasional dips in temperatures down to 10 degrees F., but the buds may be damaged. California has mostly alkaline soils. Treat these soils as needed with ½ cup of aluminum sulfate around each plant and watered in to lower the pH one point. Aluminum sulfate is sold for use on hydrangeas to make their flowers blue. Our stores carry the product in the inside garden department.
Planting camellias
Mix generous portions of organic matter into the soil removed when digging the hole. Backfill, using the enriched soil and create a watering basin with the excess soil.
When planting camellias, make sure that the ball of earth in which they are growing in is at least an inch above the level of the native soil. Planting in this fashion helps protect them from attacks by soil-inhabiting fungal diseases such as stem and collar rot.
Camellias thrive when a thick layer of mulch (3-4 inches deep) is added under the canopy. Don't let any of the mulch contact the stem or trunk of the camellia.
Watering camellias
Camellias prefer moist soils, usually normal watering practices is all that is needed to make camellias happy. Care must be given when watering camellias in heavy, slow-draining soils to ensure that the roots are not kept too wet. They like moist, but not soggy conditions. After being established (usually for one winter and one growing season) camellias will thrive on little supplemental watering. If your water is high in salts, give plants a deep soaking at least twice in summer to leach accumulated salts below the root zone.
Fertilizing camellias
Camellias are dormant from September through March. Feed camellias in April, June and August, when they are growing, using a specially formulated fertilizer such as Superfine Azalea, Camellia and Rhododendron Food.
Pruning
Pruning is not usually needed for camellias to stay healthy and produce those fantastic flowers. Some growers remove small branches and twigs that are found on the interior of the plant. The leaves of the small branches can be a haven for scale and other pests.
Pruning of camellias should be done after blooming and before new growth begins. You can do some minor snipping or remove entire branches at any time. Pruning after the new growth starts may result in the loss of flower buds.
Major rejuvenation of an old, non-flower-producing camellia is best done in a two-step process. Remove all branches from the bottom two-thirds the first year. New growth will appear from the cuts and form short branches. During the second year cut off the top one-third and remove any crowded branches on the remaining section. Be aware that few flowers are produced until the plant has produced the flower-bearing wood.
Disbudding
Some camellias produce too many flowers. Many gardeners disbud camellias in the summer to get bigger blooms and the correct spacing of each flower so that each flower may open unhindered. Some camellias have a tendency to concentrate their bud set on the terminals of the branches instead of distributing them fairly evenly.
Disbudding is done from September to November. To disbud camellias from the terminals of branches, remove the thick fat buds as desired, leaving the thin leaf buds. Usually, removing the buds leaving about 2-4 inches between the remaining buds is all that is done to give a strong showing of individual flowers.
Pests and diseases
- Insects: Aphids and scale insects are the most common insects bothering camellias and both are easily controlled with insecticides.
- Diseases: A fungal disease called "petal blight" (Sclerotinia camelliae) can infect the flowers of camellias, first turning the edges brown and then turning the entire flower brown. There is currently no control for this airborne disease other than destroying the infected flowers immediately and keeping debris cleared from under the shrubs, preventing future attacks.
Physiological problems
- Poor soil containing excess salts can inhibit the growth of camellias. Heavily leaching these salts twice during the summer months will help correct the problem.
- Leaf scorch, or sunburn, may occur if the camellia is exposed to strong sunlight.
- Yellow leaves, with the veins showing green, indicate a chlorotic condition caused by an iron deficiency in the soil. Treat the soil with a product containing iron chelates, the only sure method for treating iron chlorosis.
- Yellowing leaves with both the veins and interveinal leaf surfaces turning yellow indicate a nitrogen deficiency. Feeding the camellia with Superfine Azalea, Camellia and Rhododendron Food will help solve the problem.
- "Burned" leaf edges, corky lesions on the leaf or excessive leaf drop usually indicate overfertilizing.