Tuesday, September 22, 2009

Growing Hardy Camellias

Growing camellias in Tennessee is no longer a dream. Through the efforts of several plant breeders, particularly Dr. William L. Ackerman of the U.S. National Arboretum (retired) and Dr. Clifford Parks of Camellia Forest Nursery, as many as 40 cultivars of winter hardy camellias to -15 °F are now available in nursery commerce. Flower colors range from white and many shades from pink to red.
A great camellia possesses big bloom size, long flowering time and dark green evergreen foliage. Beginners should start with a few outstanding cultivars. ‘Pink Icicle’ (pink semi-double), ‘April Tryst’ (dark red anemone) and ‘April Remembered’ (pink semi-double) begin blooming from late winter thru mid-April. The “winter” series with cultivar names such as ‘Winter’s Star’ (pale pink single in photo) and ‘Winter’s Interlude’ (pink anemone) bloom in early autumn. Currently, the spring-flowering cultivars stand out as possessing the best foliage quality year-round. Fall flowering cultivars have proven to be more dependable in northeast TN where spring frosts are very common.
As soon as the ground can be prepared, balled and burlapped (b&b) plants are planted during late winter to early spring and again from late summer thru mid-October. Container-grown plants may be planted from late winter to mid-October.
In general, the cultural practices for growing camellias are similar to those for azaleas, rhododendrons and hollies. Plants become fully established in two years. Camellias prefer an ideal pH range between 5.5 to 6.5. Camellias are best planted on the east or north side around a home or other buildings on site, preferring filtered sunlight through nearby shade trees rather than from direct sunlight in the afternoon. Low winter humidity may cause premature leaf and flower bud loss. It may be valuable to constructing a burlap windbreak to protect camellias planted in fully open areas.
Add a generous amount of organic matter such as compost, leaf mold or sphagnum peat to the soil. Be careful not to plant camellias too deeply. The crown of the shrub should be planted slightly higher than the surrounding soil. Followed up with the addition of 2 - 3 inches of mulch to help retain soil moisture and to minimize ground freezing and thawing over the winter months. Shrubs may be adequately watered over the first two years, particularly during periods when natural rainfall is low.
Camellias are light, constant feeders. A six-month slow-release fertilizer, applied in late March, should properly feed plants through late summer. An alternative strategy is to nourish plants with an acidifying fertilizer such as Hollytone™, Miracid™ or equivalent once in the months of March, May and July. No nitrogen-based fertilizers should be applied after mid-August to prevent potential bark splitting and other winter injury symptoms.
Many cultivars grow 9 -10 feet in height and 6 - 8 feet in width. Timely pruning shape shrubs to fit within their garden spot. Camellias generally need minimal pruning to remove weak or dead branches, to control shrub size, to develop dense, fuller branched plants, and to renew the vigor of older plants. Renewal pruning for older camellias is best performed in spring before the plants have broken vegetative buds. Taller growing cultivars like 'Pink Icicle' and 'Winter Star' may demand more rigorous cutting back to achieve better plant spread and compactness.
Camellias enjoy relief from most of the pest problems that plague them further south. Significant disease and insect problems may become more common as the popularity of camellias increases. Disease problems are best avoided by planting camellias in the proper location with proper sun, good soil drainage and air movement and supplemental irrigations during extremely dry weather periods. Long summer dry spells often lead to greater outbreaks of stem canker diseases. The leading pest of camellias is scale. Plants should be inspected prior to purchase from garden centers which purchase camellias from nurseries further south.

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