Tuesday, July 28, 2009

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.

Thursday, July 23, 2009

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.

Tuesday, July 21, 2009

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

Thursday, July 9, 2009

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.