Fall Lectures Offered by Master Gardeners

Gardening in the mountains of western North Carolina can be a joy and a challenge at the same time. The Henderson County Master gardeners are here to help you with your garden needs throughout the year. This fall, we have scheduled a five educational opportunities in the form of a lecture series. The small fee of $5.00 per participant for each program is used to support future educational projects of the Master Gardeners. Each lecture will be held on Monday afternoons in August, September, and October at 2:30pm in the classroom at the Bullington Center.

August 10th - Growing Green: Organic and Companion Gardening
August 24th, - Winter Blooming Plants
September 14th - Beauty from Bulbs
September 28th - Frugal Garden Design
October 12th - Japanese Garden
October 26th - Turning your Beds in for the Winter

For more information or if you are interested in attending any of these lectures, please call 697-4891 to pre-register.

Potatoes Producing Fruit?

Have you ever noticed green marble size fruits amid the foliage of your potatoes at the end of the growing season? If so, these are the fruit which yield approximately 300 true seeds. Seeds like these are used by potato breeders to find potential new cultivars as each one is genetically distinct.

The edible tubers are actually enlarged, underground stems. Normally, most potato flowers dry up and fall off the plants without setting fruit. A few flowers do produce fruit. The variety 'Yukon Gold' produces fruit more heavily than most varieties.

Potato fruit, as well as the plant itself, contain relatively large amounts of solanine. Solanine is a poisonous alkaloid. The small fruit should not be eaten.

Just for fun, clean and save some of the seeds and plant them inside in mid-March. After frost danger has passed, transplant the potato seedlings into the garden and wait. See what you get! You may be surprised at how different the potatoes are from plant to plant.

Late Blight on Tomatoes

Late blight of tomatoes, caused by Phytophthora infestans, is knocking on the doors of our state border. On Monday, July 6, we confirmed late blight in a commercial tomato field in North Georgia (Dillard, Georgia). Recent rain and cool temperatures have been conducive for the pathogen’s growth and spread, so we are concerned the disease will soon be occurring here.

Without proper preventative measures, late blight can completely defoliate and destroy a crop within one to two weeks. The disease can be severe on tomatoes grown in the mountains of North Carolina, as well as in late plantings in the Piedmont.

The first symptoms of late blight on tomato leaves are irregularly shaped, water-soaked lesions on lower leaves. During high humidity, white cottony growth may be visible on underside of the leaf. As the disease progresses, lesions enlarge causing leaves to brown, shrivel and die. Fruit lesions appear as dark, greasy spots that eventually turn a chocolate brown color, and can enlarge to the point of encompassing the entire fruit.

Refer to the following website for more details on the symptoms of this disease. The application of fungicides plays a significant role in the control of late blight. Fungicides containing copper, chlorothanonil, or mancozeb are recommended for treatment in home gardens.

New breeding lines resistant to some strains of P. infestans have recently been developed at the Mountain Horticultural Research and Extension Center in Fletcher, North Carolina by tomato breeder Dr. Randy Gardner. A new small fruited variety called Mountain Magic that has resistance to some strains of P. infestans, in addition to early blight, should be available to growers in the future.

Taken from Pest News - Volume 24, Number 13, July 10, 2009 - Kelly Ivors, Extension Plant Pathologist, NCSU

Fall Webworms

As a result of Diane’s last post about bagworms, we received this question: Is that what shows up later in the summer on trees that look like LARGE spider webs? If not, what's that? The answer is no. What you are seeing later in the summer are actually fall webworms (Hyphantria cunea). Although the webbing looks bad and the adult caterpillars devour many leaves, the tree is rarely in danger because it has had ample time to store food for the winter. For more information and control methods, see: http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note46/note46.html

Time to treat for Bagworms

This week I have seen a few samples of Japanese Maples in the hotline office with severe bagworm feeding damage. Bagworms feed on many trees including maple, boxelder, sycamore, willow, black locust, elm, linden, poplar, oak, apple, wild cherry, sassafras, and persimmon; but the preferred hosts are conifers.

Beginning in late May through mid-June, larvae of this native moth feed causing defoliation on their host plants. Damage is most noticeable on ornamental plantings rather than in forests and woodlands.

The bags they create are camouflaged with pieces of plant material, and may be mistaken for natural parts of the tree. Females do not look like moths (no wings, legs, antennae, eyes, or mouthparts) and remain in silken bags throughout their entire lives. When larvae are fully grown, their protective bag is 1.0 to 1.5 inch long.

In late summer, male moths (black, with nearly clear wings approximately 1 inch across), emerge from their bags after pupation. One generation occurs per year.

Where practical, bagworms can be removed with scissors or a sharp knife. Chemical control is effective, particularly in June and early July when the bags are small. Recommended insecticides include Dipel and Sevin.

Look out for leaves of three.. but don't be fooled

Anyone who knows me has seen the importance of why I should stay away from poison ivy. This woody vine occurs as a weed of landscapes, woods, and fields. Poison ivy is the major cause of allergenic dermatitis in the eastern United States, which causes inflammation, blistering, and itching of the skin. Honestly, it can be down right painful and uncomfortable!

This first photo Here is a photo of some poison ivy climbing a tree here in Jackson Park.

Leaves occur on petioles and are divided into three leaflets which are generally oval in shape. Leaflets may be either toothed, untoothed, or lobed. Older leaves are generally either toothed and lobed or untoothed and lobed.

The two lateral leaflets occur on very short petioles, while the central leaflet occurs on a much longer petiole. Although leaf shape is highly variable, the lateral leaflets are often distinctly lobed on one side of the leaflet and not on the other. Each leaflet is hairless and ranges from 3/4 to 4 inches in length and width.

This picture taken a few feet from the first picture is not poison ivy, but instead it is boxelder. A tree in the maple family that is commonly mistaken for poison ivy. If you look closely, you will see that the leaflets of a boxelder are opposite and those of poison ivy are alternate.

For more information of poison ivy, visit this site Poison Ivy.

"Dog Vomit" Slime Mold

There’s been a bumper crop of slime molds in landscape beds this year, and we’ll see them throughout the summer and into the fall. By far the species most often noticed is Fuligo septica, a.k.a. the “dog vomit” slime mold. Despite the unpleasant name, it is completely harmless to humans, animals and plants.

Slime molds spend most of their lives as amoeboid cells or inconspicuous plasmodia that creep slowly through soil, leaf litter, mulch, etc. A plasmodium feeds by engulfing bacteria, spores, and bits of organic matter. It eventually moves out to a more exposed location on top of mulch, pine straw, a stump, a low-growing plant, or even the foundation of a building. There it stops moving and transforms into a fruiting (spore-producing) body. This is when Fuligo septica first gets noticed as a bright yellow, frothy mass a few inches to up to a foot in diameter. It quickly fades to a dull orange and then a light tan as its surface dries to a crust. After a few days it breaks apart to release its dark-colored spores, which blow away to start the life cycle anew. Within a week or two, all that’s left is a dusting of leftover spores and bits of gray or yellowish crust.

Control measures for Fuligo septica are neither effective nor necessary. If considered intolerably unsightly, they can be removed by hand or washed off with a hose, but there's a good chance that new ones will pop up at a later date, though probably not next year, unless new mulch is applied.

Written by: Mike Munster, Department of Plant Pathology