Garden Talk: August 14, 2008
From NGA Editors
Vanilla-Scented Verbena Perfumes Your Yard
Verbenas are stars of the late-season annual flower garden. They are great butterfly attractants and provide an airy feel to the garden as their flowers float above the foliage. Now there?s a tropical verbena selection that has a strong fragrance as well.
Sweet almond verbena (Aloysia virgata) is also known as incense bush for its intoxicating vanilla fragrance that's strongest in late afternoon and evening. It blooms freely until frost with spires of white flowers. In warm areas this drought-tolerant native of Argentina and Brazil grows 8 to 15 feet tall, and the roots are hardy to USDA zone 8. In all but frost-free areas the plant dies back to the ground in winter. In containers it is more manageable, growing only 2 to 4 feet tall. Sweet almond verbena grows best in full sun in well-drained soils.
For more information on this tropical verbena, go to: Logees Greenhouses.
Neem May Inhibit Nitrogen-Fixation in Legumes
Neem extract is widely used to ward off a variety of insects, such as Japanese beetles, aphids, and scale, and also diseases such as powdery mildew. It?s derived from the seed of a tropical tree and not considered harmful to beneficial insects, pets, or humans. But even an organic pesticide can have adverse effects on the environment.
Researchers at National Polytechnic Institute in Mexico studied the effects of neem oil on bean growth and rhizobium-nodule formation. Beans, like many legumes, have a symbiotic relationship with these soil-dwelling bacteria. The bacteria form nodules on the bean plant roots, which, in essence, make nitrogen fertilizer for the bean plants by utilizing nitrogen from the atmosphere.
In the study, bean plants were treated with neem oil extract, mata-raton extract (a plant extract used as an insecticide), and a chemical insecticide. Researchers found that the number of nitrogen-fixing rhizobium nodules in the neem-treated plants was 2.1 times lower than bean plants treated with the chemical insecticide, and 1.6 times lower than the mata-raton extract-treated beans. Results suggest using neem extracts on legumes can inhibit this symbiotic bacterial relationship and should be avoided.
For more information on this research, go to: Journal of Agronomy for Sustainable Development.
Gardening Improves Health of Older Adults
It?s widely known that regular exercise contributes to the prevention of chronic diseases associated with aging and helps maintain an independent lifestyle. While many seniors find regular exercise boring and inconvenient, gardening is a popular leisure activity of this population. Researchers at Kansas State University wanted to see if gardening alone can supply the recommended amount and intensity of exercise needed for seniors to stay healthy.
Researchers randomly recruited seniors from Manhattan, Kansas, and investigated the exercise intensity of nine different garden tasks: gripping, stooping, lifting, stretching, walking, standing, kneeling, sitting, and squatting. They regularly measured heart rate, oxygen usage, energy expenditure, bone density, and hand strength.
Results indicated that the nine gardening tasks gave seniors low to moderate physical activity and met the recommended 30 minutes of daily moderate physical activity. Participation in gardening was found to be a predictor for leading a physically active lifestyle and for high life satisfaction in older adults.
For more information on this study, go to: Kansas State University.
Faux Coyote Scares Away Birds
From the manufacturer who brought you the scare-eye balloons and faux owls to help ward off unwanted birds comes another faux predator for your yard. The faux coyote is not just a one-dimensional cutout of this prolific predator. The decoy is three-dimensional and the tail moves with the breeze. It gives birds, such as Canada geese and seagulls, and land animals, such as skunks and rabbits, the impression that a predator is lurking about. The decoy is attached to a stake that you stick in the ground.
As with any stationary scare tactic, it helps to move it around the yard every few days so the birds and animals don?t get used to it. Also, it?s suggested that you spray coyote urine around the area to give animals a sensory, as well as visual, cue.
For more information on the faux coyote, go to: Bird-X.