• Enter your email address to follow this blog and receive notifications of new posts by email.

  • May garden tips & tasks

    GARDEN EVENTS IN MIDDLE TENNESSEE

    May 20: Master Gardeners of Davidson County Urban Gardening Festival, 9 a.m. - 4 p.m., Ellington Agricultural Center Demonstration Garden. Free admission. www.mgofdc.org; on Facebook at www.facebook.com/mgofdc.

    June 10: Middle Tennessee Daylily Society show and sale, Ellington Agricultural Center’s Ed Jones Auditorium, 440 Hogan Rd. in Nashville. Sale open at 10 a.m.; show opens to the public at 1 p.m. To learn more about the Middle Tennessee Daylily Society, visit www.middletndaylilysociety.org.

    It’s time to plant those tender herbs and vegetable transplants, such as basil, dill, tomatoes, green peppers, hot peppers, eggplant.

    If tomato transplants are already too tall and leggy, you can plant them on their sides and cover the long stems with soil. The stem tips will turn upward, and the buried stems will sprout roots.

    Sow seeds of bush beans and pole beans, cucumbers, sweet corn, melons, okra, field peas, pumpkin, squash and zucchini. Follow the directions on the seed package for planting depth and spacing. Vegetables grow best in full sun.

    Cut the faded blossoms of peonies. Fertilize the plants lightly in late spring or early summer.

    Remember the basics of watering: morning is best, so plants’ leaves have time to dry before evening. Lawns, perennial borders and annuals like to have 1 – 1½ inches of water per week.

    Many indoor plants enjoy a summer vacation outdoors. Give them a cool, shady spot in the yard, and don’t forget to water them.

    Prune thyme frequently so it will stay full and green in the center.

    Weeding is easiest after a rain. If the ground is too dry and you need to weed, soak the bed first with a hose or sprinkler.

    Whether they’re growing in the ground or in pots on the porch, pinch the tips of geraniums from time to time to encourage them to branch out and to produce more flowers. Geraniums in pots benefit from regular feeding with a water-soluble fertilizer.

    Remember that mulch can be a gardener’s best friend. Pine straw or composted leaves are good alternatives to hardwood mulch.

    Harvest herbs as they reach their peak. Dry small leaves on a screen, hang small bunches of long-stemmed herbs in a warm, dry room out of the sunlight.

    Plants growing outdoors in containers dry out quickly when it’s hot. Check them daily, and water as needed.

    Don’t go near hydrangeas with the pruning shears unless all you’re cutting is dead branches. If the bigleaf hydrangeas look like they’re not going to bloom, it could be that the buds were nipped in a late cold snap, or the plant was pruned too late last year.

    As the flowers of Shasta daisies begin to open and then to fade, keep them clipped off. This prolongs the blooming season of daisies (and most other annuals and perennials), and keeps the plants looking better, as well.

    Watch for aphids on shrubs and perennials. A strong blast of water from a hose will remove many of them, or spray with insecticidal soap.

  • Categories

  • Archives

Prevent powdery mildew

QUESTION: How do I keep my beautiful zinnias from getting powdery mildew? It may be too late for this year, but what should I do different next year?

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

The best defense is to give zinnias room to grow without crowding, which allows air to circulate better around the plants, and water only in the morning, so the foliage has time to dry before nightfall. Cut back on the use of high-nitrogen fertilizer, which produces succulent new growth that is a major powdery mildew magnet. Grow them in full sun; hot temperatures (above 90 degrees) inhibit the growth of mildew.

There are fungicides available that should be applied as soon as you begin to spot the mildew (so yes, probably too late for this year), but I always suggest trying the good-cultural-practices method first. The University of Tennessee Extension has a short list in a publication about powdery mildew here. If you decide to go that route, be sure to read and follow directions on the product label.

Zinnias are not the only things 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.

 

Advertisements

One Response

  1. […] out for powdery mildew on plants and destroy infected leaves! How to prevent powdery mildew: http://j.mp/NzX86p TwitterFacebook […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: