Rare 10°F With Snow in Georgia on Camellia sinensis. They took a hard hit because of exposure.
Dr. William Ackerman was without question considered one of the leading authorities on breeding and growing cold hardy camellias. Here is an article that he shared with us several years ago. We have added many images of some of his cold hardy hybrids that we took from plants that Dr. Ackerman also shared with us. Dr. Ackerman passed away in July of 2013, but his legacy lives on with the many cold hardy camellias that he developed over the years.
Few woody ornamental shrubs provide as much year-round pleasure as Camellias. During the bleak days of winter, when many plants are dormant, camellias dress up the landscape with their elegant flowers; dark, lustrous, evergreen foliage, and various leaf shapes and textures. A variety of habits abound: from prostrate to columnar, and open to dense.
Cold-hardy camellias have long been a dream of Northern gardeners. Unfortunately, until recently, camellias have not been widely grown beyond the ‘Camellia Belt’ (from South-east to the West Coast; USDA Zones 7 to 9), because of a well-established myth that camellias are not cold-hardy. Yet, many new cold-hardy varieties are just waiting to be used in Northern climates. In the Northeast, judicial selection of fall- and spring-blooming cultivars can result in extended flowering periods, from early October to late April with a break in January and February.
For decades, horticulturists in the North have tried growing Southern camellias – often unsuccessfully. While some camellia cultivars seem to tolerate harsh winters, reliable hardiness was unattainable. These frequent failures further supported the camellia’s reputation for tenderness until recently.
Fortunately, the discovery of an obscure U.S. Department of Agriculture introduction of C. oleifera from northern China with a proven hardiness, has revolutionized the camellia world. C. oleifera grown in the Orient for almost 5,000 years as a source of cooking oil pressed from its seeds, this species has many strains and forms. A survey made in China in 1999, reported that C. oleifera was being grown over an area of 9.7 million acres in that country. This is roughly equivalent to the land area of the Maryland and Connecticut combined. It is not surprising that a select few developed extreme cold hardiness in the northern locations.
An extensive breeding program established at the U.S. National Arboretum in the late 1970’s, incorporated the cold hardiness of C. oleifera with the elegant flowers of the most widely grown standard varieties. As a result, we have a range of both spring and fall-flowering varieties being grown widely through areas of coastal New England, parts of the Mid-West Great Lakes area, and the Lake areas of Canada.
As stated earlier, if northern gardeners are to grow their camellias successfully, they need to follow certain basic principles specific for their climate.
- SPRING PLANTING rather than fall planting, as usually recommended in the South. This gives the plants a full growing season before the onset of winter.
- Avoid full sun, especially early morning sun. An over-story of evergreen shade trees providing winter protection from sun and wind, is ideal.
- DO NOT PLANT TOO DEEP, the top of the media in the container should be level, or slightly above the surrounding ground.
- Mulch ith pine needles, pine bark, or no –packing leaves, to a depth of 3-4 inches. Camellias prefer
- Slightly Acid, well, drained soils similar to azaleas and rhododendrons.
- Newly planted camellias may need some cold weather protection during the first several winters. A wind and sun screen may be made with a circle of stakes around the plant, and then wrapped with burlap (or Microfoam) with several inches of dry leaves are examples. If a source of Microfoam can be found, it is not necessary to use leaves.
- DEER love the tender camellia leaves! Fence small plants, or cover with black netting.
Numerous books and articles on the best camellia varieties and their culture have been written by, and directed towards, growers and landscapers in the South (’Camellia Belt’). While these publications are valuable for growers in that area, their recommendations can be misleading and sometimes, disastrous, in northern climates.
A book ‘Beyond the Camellia Belt’ by Dr. William Ackerman, gives comprehensive advice on succeeding with camellias in colder climates. A few examples of which are included above. The book also includes descriptions and photos of the 65 cold hardy varieties recently introduced by the U.S. National Arboretum, Washington, D.C.