Garden Talk: October 27, 2005
From NGA Editors
Red-Stemmed Willow Adds Beauty to the Winter Garden
It's often difficult to find color in the winter garden, especially in northern climates. One of the best ways to introduce color during this dark season is to grow trees and shrubs with brightly colored bark. A new variety of willow can be added to the list of possibilities especially if you're planting in a wet area.
'Britzensis' white willow (Salix alba 'Britzensis') is a fast-growing variety that can grow 6 to 8 feet in one season. Left unpruned, it will reach 20 feet tall and wide. Most gardeners, however, will want to prune it back to 2 feet tall in late winter to encourage the new colorful growth. The bark on new shoots turns a brilliant red and orange in fall and winter, rivaling the showiest red-twigged dogwoods. 'Britzensis' grows best in full sun in USDA zones 2 to 8. Because it can tolerate wet soils, it's an excellent choice for growing in moist soils along streams, ponds, or in low spots where other shrubs don't thrive. Prunings from this willow are also excellent for use in floral design and basket making.
For more information about this easy-to-grow, colorful shrub, go to: Bluestem Nursery.
Calcium Fertilizer Helps Trees Survive Winter
With winter around the corner, many gardeners will be preparing their landscape plants for the coming cold temperatures. With an estimated 1 million urban trees worldwide dying each year from freezing temperatures, researchers are trying to find ways we can better protect plants. A study in England suggests that fertilizing in fall with calcium nitrate can help trees survive both freezing temperatures and salt damage from products used to de-ice roads and walkways.
Researchers broadcast calcium nitrate fertilizer around three-year-old evergreen oaks (Quercus ilex) and hollies (Ilex aquifolium) at the rate of 4, 8, and 16 pounds per 1000 square feet during the month of October. They picked off the leaves at intervals of 1, 2, 4, and 8 months after the fertilizer application, and tested them for their physiological response to low temperatures and high salt levels. Leaves from trees that received 8 pounds of fertilizer were significantly more tolerant of low temperatures and high salt levels than the control or other treatments. Lower amounts of fertilizer didnt enhance cold tolerance, and the higher amount (16 pounds) damaged the foliage. This research coincides with earlier research that showed similar results when applying calcium fertilizer to deciduous fruit trees and landscape trees.
For more information on this research, go to: Journal of Arboriculture.
Practical Science for Gardeners
Fall and winter are great times of year to "bone up" on your garden reading. In addition to the books on designing your garden and growing specialty plants, pick up this new book by English author Mary Pratt. It will help you understand what's going on inside your soil and plants, making you a better gardener in the process. Practical Science for Gardeners (Timber Press, 2005; $24.95) delves into the basic science behind topics such as seed germination, plant propagation, and soil structure, in an entertaining and easy-to-understand manner. It also covers current hot topics, such as encouraging biodiversity in the garden, preserving wetlands, building ponds, and understanding genetically modified plants.
This is a great book for educators working with kids or any adult looking to fully grasp the inner world of their garden and plants. Pratt also peppers each chapter with practical tips on how to translate the scientific principles learned into useful gardening suggestions.
While specific plant examples pertain mostly to England and northern Europe, the principles highlighted are universal. The book also features a chapter on plant classification and naming, and a glossary of botanical terms.
For more information on Practical Science for Gardeners, go to: Timber Press.
Appreciation for Nature Begins in Childhood
Many gardeners can trace their love of plants and nature back to childhood memories of gardening with relatives or friends. New research from Washington State University confirms what many gardeners have thought all along: kids who are exposed to gardening and nature when young exhibit positive attitudes towards the environment and nature as adults.
Researchers conducted 2000 phone interviews with adults in large urban areas across the country. They analyzed the influence of demographics and childhood experiences on answers to the following three questions: Do trees in cities help people feel calmer? Do trees have a particular personal, symbolic, or spiritual meaning to you? and During the past year, have you participated in a class or program about gardening?
The results indicate that both passive (growing up around natural elements such as trees and flowers) and active (picking flowers, planting trees) interactions with plants when young resulted in strong positive adult attitudes towards trees and nature. The highest correlation came with adults who actively gardened as kids. This suggests that gardening programs for kids who arent normally exposed to gardens and plants can foster a better appreciation of gardening and the environment when theyre adults.
For more information about this research, go to: HortTech.