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  • Upcoming Garden Events

    Sept. 30: The Nashville Herb Society presents Through the Garden Gate: A Glimpse of Edwardian England, 8 a.m. – 3 p.m. at Cheekwood Botanic Hall. Celebrate the gardens, foods and flowers that delighted Downton Abby family and friends at the turn of the 20th century. The event begins with a hearty Edwardian breakfast, followed by three speakers: Marta McDowell on Beatrix Potter’s Gardening Life; Geraldine A. Laufer on Tussie Mussie – Victorian art of expressing yourself in the language of flowers; and Terry White, The English Garden event florist . Registration includes breakfast, box lunch in the garden with music, English tea and cookies. To learn more or to register, visit www.herbsocietynashvlle.org.

    Tips & tasks – September

    Cut the dead tops of coneflowers, but leave enough for goldfinches to enjoy the seeds.

    Plant cool-weather vegetables for a fall crop: spinach, mustard and turnip greens, radishes, leaf lettuce.

    Start a new lawn of cool-season grass, such as fescue, or refurbish or repair establish lawns.

    Don’t let the soil of newly planted grass dry out. New grass needs about an inch of water per week.

    It’s still warm, so continue to water and weed garden beds as needed.

    Remove dead foliage, spent flowers and other garden debris; replenish mulch as needed.

    Continue to harvest produce, which may be getting a boost now from slightly cooler weather. Keep watering sage, rosemary and other perennial herbs so they’ll be in good shape to get through winter.

    Prepare to bring houseplants back indoors: remove dead leaves, scrub soil from the sides of the pots, treat for insects. Bring tropical plants in before nighttime temperatures dip to 55 degrees.

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Keep zinnias free of powdery mildew

QUESTION: I love zinnias and plant them every year. Sometimes they do well and look great all summer, but many years the leaves are covered in powdery mildew. How do you get rid of this problem?

Powdery mildew is a fungus that appears as gray or white splotches on leaves, stems and flowers of zinnias and other ornamentals and some vegetable plants. It travels by airborne spores, and thrives when nights are moderately cool and foliage stays damp. A mild covering of powdery mildew is merely unattractive, but a severe case can cause distorted shoots and leaves, misshapen flowers, or can prevent flowering altogether.

The best defense is to grow zinnias in full sun, since hot temperatures inhibit the growth of mildew. Don’t allow them to get too crowded; you want air to circulate freely around the plants. Water only in the morning so foliage has time to dry before nightfall.

I always try to suggest the good-cultural-practices methods first for problem-solving, but there are also fungicides available that can deter powdery mildew. If you choose that route, apply fungicide as soon as you begin to spot the mildew. The University of Tennessee Extension has a short list of products in a publication about powdery mildew here. Be sure to read and follow directions on the product label.

Zinnias are not the only garden favorites plagued by powdery mildew. Lilacs, roses, crepe myrtles and other woody ornamentals, and many herbaceous ornamentals and bedding plants are also targets when weather conditions favor the fungus.

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