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  • March garden tips & tasks

    If your fescue lawn looks a little skimpy, overseed early this month. Fescue grows best when the weather is still cool.

    Clip dead stems from perennial herbs – thyme, sage, lavender, rosemary. Pruning encourages vigorous new growth.

    Prune nandinas, flowering quince and other airy shrubs by reaching in and removing about a third of the branches at ground level.

    Remove mulch or leaves that may be covering perennials in garden beds.

    Prepare a new garden bed: Have the soil tested (check with your county’s Extension service). Remove grass and dig or till soil 8 to 10 inches deep and mix with soil amendments and organic matter to improve drainage.

    Add fertilizer lightly to perennials as soon as you see new growth. Too much fertilizer may result in lanky growth.

    Herb transplants that don’t mind cool weather -- parsley, cilantro, sage, oregano – can go in the ground now.

    When you cut daffodils to bring inside, cut the stems at an angle and place them in water right away. Change the water in the vase daily to keep them fresh longer.

    Save the date - Middle Tennessee garden events

    The Perennial Plant Society's annual Plant Sale will be April 8, opening at 9 a.m. at The Fairgrounds Nashville. The sale offers newly released and hard-to-find perennials from top local nurseries -- more than 450 varieties of perennials, vines, grasses, shrubs and annuals. The event supports local scholarships for Tennessee horticulture students and monthly gardening programs, open to the public, at Cheekwood Botanical Gardens. For information visit www.ppsmtn.org.

    The Herb Society of Nashville's annual Herb Sale will be April 29, 9 a.m. - 2 p.m. at The Fairgrounds Nashville. The sale will offer heirloom vegetables, rare varieties of perennial and annual herbs, handmade pottery herb markers and more. To learn more, visit herbsocietynashville.org.

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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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