Over the past two summers I’ve been experimenting with various begonias to test their suitability as yard plants. Before starting the work, I established several judging criteria, for obviously if one is careful, you can usually find some spot in the yard for about any begonia. No, I wanted to go one step farther and find plants the met some tough requirements; those varieties that would thrive in the ground as perennials in a typical flowerbed, and with little special care. The specific criteria were:
1. Resistant to freezing: able to withstand 25 degrees Fahrenheit for several hours without cover, or longer with light cover.
2. Quick growing: the plant must rapidly recover once spring arrives.
3. Large in size: attain a height of at least two feet in one growing season, three to four feet preferred.
4. Sun resistant: able to withstand 2 to 4 hours of direct sun during some part of the day.
5. Attractive: I like them all, but the reds, silvers and pure greens are especially nice.
In addition, I wanted some ground covers with all these requirements, except height, to fill in around these plants to enhance the overall appearance.

I started this work by planting six-inch pots of over 70 different varieties in various spots in eight large flowerbeds all around the yard. Sun intensity varied widely from full shade to full sun. It quickly became apparent that high levels of sunlight would burn almost all plants when they are first exposed. Even the best, most sun-resistant plant takes some time to build up its immunity. As an example, I put an especially fine specimen of B. nelumbiifolia into a location with four hours of direct afternoon sun. It immediately sun burned, loosing all of its leaves. I then moved the plant (a bare rhizome) to a shaded area and over a two-month period, slowly exposed it to more and more direct sunlight. Finally, the plant was able to withstand the same four hours of direct sun that had previously burned it.

The ability to withstand low temperatures, and recover is a must for me. I want these plants to be perennials, not annuals. The first spring I was surprised that many of my favorites just couldn’t recover fast enough to be attractive. Among these attractive but slow or low growing varieties are B. heracleifolia, manicata, paleata, Cajon Valley, Rip Van Winkle, and Sir John Falstaff. Before long, I realized that I needed to concentrate on large growing varieties. That conclusion seems obvious now, but at the time, I was enchanted by some low growing rhizomatous plants that just can’t make it in the flowerbed.

Let me now share my results after these two years of experimentation. For canes, most will meet all the above requirements except direct sun exposure. Among those that I tested that were especially nice were B. Di-Erna, Hazels Front Porch, Superba Kensii, Emerald King, Esther Albertine, and Sophie Cecile. Several others show promise but need more time in the ground to get the size desired. I find that canes need something special to really make it in the sun. One such special ingredient is U062. There are currently five very attractive and popular canes that have U062 in their background, namely B. Burning Bush, Serenity, Sinbad, Don Miller, and Maurice Amey. These plants with their red and silver coloration will take a high level of direct sun without burning. Of course U062 is the most sun resistant, but it will not tolerate cold and dies somewhere around 40 degrees. The variety B. Looking Glass also appears to be sun resistant to some degree.

Many of the red tinted rhizomatous variety are good under the conditions tested, the best being B. Selph's Mahogany, Lucky Stars, Bashful Bandit, Plum Gorgeous, Risas Reward, and Kit Jeans Mounger. These plants will take the elements, cold or sun, and just keep coming back for more. Some of the black rhizomatous plants, B. Black Coffee, Black Velvet, Black Beauty, and Joe Hayden, are almost as good but are smaller, don’t recover as fast, and may not be as sun resistant.

When we go to dark green/red/silver colored plants we find several winners, most of which are quite large. I especially like B. Big Mac, Mary Bucholtz, Mirage, Shadow Box, and Caribbean King. Each of these will exceed three feet in height, quickly, and have large luxurious leaves. For the light green colored plants, my favorites are B. nelumbiifolia, popenoei, sericoneura, fribergensis, Holly Moon, and Washington State,. Anyone of these makes a great accent plant to enhance any flowerbed.

Finally, for ground cover I found that B. convolvulacea, Withlacoochee, and Panasoffkee will rapidly return the next spring and get more lush and vigorous throughout the summer. In closing I’ll note one last thing; if I only grew seven begonias as yard plants they would be B. nelumbiifolia, scabrida, Caribbean King, Washington State, Plum Gorgeous, Risas Reward and Di-Erna; the best of the best.

bec: 11/1/05