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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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Evergreens turning ever-brown

QUESTION: We are seeing many evergreen trees — Leyland cypress and others — with big sections of brown limbs. Is that due to the drought? Or is there some other problem affecting the trees?

The drought this summer plays a big part in the browning of Leyland cypress, but it’s not the whole story. Alan Windham, at UT Extension’s Soil, Pest and Plant Center says the branch dieback is the result of a one-two punch: drought and seirdium canker, a fungus that appears on branches or stems and in branch axils and causes the branch to die. “I’ve seen more damage this month than I can remember in several years,” Windham says.

I found a good description of seirdium canker at the Web site of North Carolina State University’s Plant Pathology Extension: The cankers are brown or purple sunken patches on the bark, and may be accompanied by a flow of resin. Affected branches may be scattered randomly throughout the tree; they turn a reddish-brown color, in striking contrast to the green, healthy foliage. The fungus can be spread by splashes of rainwater or water from sprinklers, or it can travel from branch to branch on unclean pruning tools.

There are no chemicals recommended to control the canker. Brown branches should be pruned and destroyed as soon as possible. Prune at least an inch below the canker, and sterilize the pruning tools between cuts by dipping them in rubbing alcohol or a solution of 1 part chlorine bleach to 9 parts water. Plants that are severely affected should be removed and destroyed. Watering by drip irrigation during drought can help prevent problems, Windham says.

Upright arborvitae are also having trouble due to the drought. Windham explains: Plants have different strategies to survive: some plants sacrifice older leaves to protect new shoots; some have waxy leaves, some plants roll their leaves or close up to prevent water vapor from escaping.

“Then you have plants like arborvitae, where it’s all or nothing. It’s as if the plant is saying, ‘We’re going for broke. Everything survives or nothing survives.’ Well, this strategy didn’t work out too well for many arborvitae I have seen.”

In this case, the only solution is to remove the dead trees and start again.

 

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