Garden Talk: November 10, 2005
From NGA Editors
Toast to Your Health With a Glass of Pomegranate Juice
This tropical fruit, which offers up brilliant red edible seeds, is showing up in finer restaurants as a special blend in cocktails. But pomegranates (Punica granatum) are not just trendy, they're good for your health.
Researchers at Case Western Reserve University in Cleveland, Ohio, tested pomegranate juice and found that it thwarted osteoarthritis. It appears that the antioxidant chemicals in pomegranates reduce levels of the inflammatory chemical called interleukin-1b. The antioxidants also reduce the number of enzymes that erode cartilage. When cartilage breaks down, the exposed bones are more susceptible to pain and inflammation.
This is only the first finding of the potential of pomegranate juice to fight osteoarthritis, but researchers are optimistic and plan further trials.
For more information on this research, go to: WebMDHealth.
(Photo courtesy of Cornell University)
Butterfly Bushes For Small Gardens
Butterfly bushes are well-known late summer- and fall-blooming perennials. There are a number of selections of these butterfly-attracting shrubs with different-colored flowers. However, the plants can grow large and unruly in a perennial border. A new series of butterfly bushes from England features a shorter (4 to 5 feet tall), bushier habit with larger flower trusses that are excellent for cutting.
The English Butterfly Series was developed by Elizabeth Keep of East Malling, England. Three cultivars are currently available: the pink-flowered Peacock (Buddleia davidii Peakeep), purple-flowered Purple Emperor (Buddleia davidii Pyrkeep), and the dark blue-flowered Adonis Blue (Buddleia davidii Adokeep). All three are hardy in USDA zones 5 to 9, grow best in full sun on well-drained soil, and flower on new wood produced in spring. They all should be pruned back in late winter.
For more information on the English Butterfly Series, go to: Proven Winners.
Organic Mulch Boosts Tomato Production
Heirloom tomato varieties continue to be popular among home gardeners. To get the highest production from tomatoes, some growers have been advocating the use of plastic mulch. New research in Ohio suggests that growing tomatoes in organic mulch may be even better.
Researchers at Ohio State University grew the heirloom tomato variety Nebraska Wedding with various mulches to compare production and growth. They used five different planting treatments: bare soil, black plastic mulch, shredded newspaper mulch, wheat straw mulch, and composted landscape bark mulch. The organic mulch was applied to a depth of 4 inches. One half of the plots had herbicide and fungicide treatments, and the rest did not.
The highest yields were achieved on the plots with shredded newspaper mulch, regardless of the pesticide treatment. While the newspaper mulch resulted in the lowest soil temperatures, it suppressed weed growth better than any other organic mulch. Even though the soil under the black plastic mulch reached the highest temperature, the plants had lower yields than all of the organic mulch treatments, regardless of whether pesticides were used or not. The newer red plastic mulch was not trialed in this experiment. Home gardeners may want to experiment with growing tomatoes in newspaper mulch next summer, and even do their own comparisons with red plastic mulch.
For more information about this research, go to: Ohio State University.
Add Beneficial Fungi When Planting
Many gardeners, especially those in warm areas, are still planting bulbs, trees, and shrubs, and adding soil amendments such as compost and fertilizer when planting. But the most critical additive may be fungi.
Mycorrhizae are fungi that colonize plant roots, and it's estimated that 90 percent of the plant species in the world have them, including vegetables, flowers, bulbs, trees, and shrubs. Mycorrhizae aid plant growth in several ways: they help plants absorb and hold major and minor nutrients, increase tolerance to stress and drought, and inhibit disease organisms in the soil.
While mycorrhizae are naturally occurring in healthy soils, they are deficient in many disturbed soils, soils on construction sites, and in plants grown in nurseries. You can buy special mycorrhizae formulations, and fertilizer manufacturers have been adding mycorrhizal fungi to their products as a way to boost plants' performance.
A few things should be kept in mind when using these products. Before sprinkling mycorrhizae around plants, check the soils phosphorus levels. High phosphorus in soils inhibits mycorrhizae formation, making the application a waste of money. Also, mycorrhizae are inhibited by chemical fertilizers but not by organic fertilizers, so dont apply chemical fertilizers when planting. Well-decomposed compost doesnt harm mycorrhizae, but fresh compost may inhibit their growth. Only one application of mycorrhizae is necessary per plant for its lifetime.
Finally, there are different strains of mycorrhizae; trees and shrubs benefit from a different strain than annuals and perennials, for example. And plants in the Ericacea family, such as blueberries and rhododendrons, need their own specific strain. So check the label to make sure you're getting the right product for whatever you're growing.
For more information on adding mycorrhizae when planting trees and shrubs, go to: Agricultural Research Service.