Thursday, August 30, 2012

Avoid Mosquitoes to Avoid WNV

Mosquitoes may seem to be ever-present in some yards, but in others, the return of actual rainfall means the return of great swarms of the biting pests. This summer, those biting pests have already transmitted West Nile Virus to three individuals in Cobb County, according to a news release of the Georgia Department of Public Health.

To reduce the risk of of contracting West Nile Virus (WNV), people are being encouraged by the DPH to observe the "Five Ds of WNV prevention":

Dusk - Mosquitoes carrying WNV usually bite at dusk and dawn. Staying indoors at these times can help people avoid infection.

Dawn - People who must be outside at dawn (or at dusk) should protect themselves from mosquito bites as much as possible.

Dress - Loose-fitting, long sleeved shirts and long pants reduce the amount of skin that mosquitoes can get to.

DEET - Exposed skin should be covered with an insect repellent containing the chemical DEET, which is the most effective repellent for mosquitoes.

Drain - Any containers holding standing water should be emptied, since these can become breeding spots for virus-carrying mosquitoes.

WNV can be reliably diagnosed only through a lab test, but, according to the DPH, "symptoms of WNV include headache, fever, neck discomfort, muscle and joint aches, swollen lymph nodes and a rash that usually develop three to 15 days after being bitten by an infected mosquito."

While mosquitoes are the source for the spread of this particular virus, plenty of other pests in the yard can cause irritating bites. If you are unsure about the identity of a biting insect, the UGA publication "Stinging and Biting Pests" provides helpful information to help you identify and control your yard's pests. If you are unsure of an insect's identity, it can be brought to the Cobb County Extension office for identification.



Wednesday, August 22, 2012

Let Us Grow Lettuces

Lettuce is a cool weather crop, along with other garden favorites such as collards, kale, spinach, Swiss chard, broccoli, cilantro, and cabbage. "Cool weather crops" are those that are more tender, flavorful, and generally successful if they mature while the weather is cool. Many gardeners plant these crops in the early spring, taking advantage of our beautiful spring weather, but these can also be planted in late summer to mature as the weather cools in early fall.

Most garden lettuces will reach maturity, if planted from seed, within 50 to 70 days, depending on the variety. That means that lettuce planting can begin now, to reach maturity just before and in the several weeks following the first frost. The first frost in our area usually arrives toward the end of October or early in November. Some gardeners make two, three, or more plantings of lettuce, to keep the leafy greens coming through the fall and early winter.

According to UGA Cooperative Extension's publication "Home Garden Lettuce," this particular crop will grow well in most home gardens provided that its basic requirements are met. In addition to the usual garden-veggie requirements of 10-12 hours of sunlight and "fertile sandy loam soils that are well supplied with organic matter," lettuce will grow best with a slightly acid soil pH of 6.0 to 6.5.

Lettuce can be planted in rows or broadcast across the bed. The seeds are very small, and care should be taken to not let them sink too deeply into the soil, so that they are covered by only 1/8 to 1/4 inch of soil that is tamped down lightly with the back of a hoe or with the gardener's hand.

The "Home Garden Lettuce" publication specifies that the crop needs to be fertilized both at planting and again as the season progresses:

At planting time, "In the absence of a soil test, incorporate 3 to 4 pounds of 5-10-10 fertilizer per 100 square feet of garden area." Then, "After the initial fertilizer application at planting, apply 2 pounds of 5-10-15 per 100 square feet of bed each month during the growing season."
If the gardener had a soil sample from the garden tested for nutrients in advance of planting, the gardener should, instead, follow the fertilizer recommendations that came with those test results.

For organic gardens, managing the soil for soluble nutrients requires a different timetable. The Cornell University Cooperative Extension publication "Production Guide for Organic Lettuce" explains that nutrients are released through the actions of soil-dwelling microorganisms as they decompose organic matter such as compost, animal manures, and green manures that have been incorporated into the soil: "In a long-term organic nutrient management approach, most of the required crop nutrients would be in place as organic matter before the growing season starts." Essentially, this means that, if enough organic matter is in place, much of the needed "fertilizer" is already in the garden.

In an organically managed garden, nutrient release takes place throughout the season, but it happens more slowly in cooler weather and in gardens that are new or newly transitioning to an organic approach. For lettuce, the necessary nutrients "can be supplemented by highly soluble organic amendments such as poultry manure composts or organically approved bagged fertilizer products." Examples of bagged fertilizer products include blood meal, soy meal, and alfalfa meal. Organic gardeners should follow the package recommendations for application of these products.

Friday, August 17, 2012

Upcoming Events

Tuesday, 28 Aug., 6:30 p.m. to 7:30 p.m.
Free and open to the public.
Presented by Turfgrass Specialist Becky Griffin, at Mt. View Regional Library, as part of the ongoing Gardeners Night Out presentation series of  Cobb Extension's Master Gardener Volunteers of Cobb County.

Seeding and Overseeding Fescue
Thursday, Sept. 6, 6:30 p.m. to 8:00 p.m.
Free and open to the public. Please register by calling 770-528-4070.
Presented by Cobb County Urban Agriculture Agent Neil Tarver, at the UGA Cobb County Exension Office at 678 South Cobb Drive, in the second floor classroom. Learn the fundamentals of soil prep, seeding, mainenance and more, just in time for planting.

Hydrangeas, the Garden Favorite
Friday, Sept. 14, noon to 1:00 p.m.
Free and open to the public. Bring your lunch and enjoy the presentation!
Presented by Cobb County Master Gardener Debra Stockton, at the County Water Lab at 660 S. Cobb Drive (the smaller brick building at the back of the property), as part of the ongoing Lunch & Learn presentation series of Cobb Extension's Master Gardener Volunteers of Cobb County.

Green Industry Update
Tuesday, Sept. 18, 8:30 a.m. (registration begins) to noon.
Recertification credits: 21/23/24/27 = 3hours; ISA = 2.5 hours; private = 2 hours.
$10 at the door; Pre-register with or 770-528-4070.
Landscape Irrigation with Tom Shannon of Ewing Irrigation; Dormant Season Turf Care with Patrick McCullough of UGA; Fall Diseases in the Landscape with Elizabeth Little of UGA.

When Autumn Leaves Start to Fall
Tuesday, Sept. 18, 6:30 p.m. - 7:30 p.m.
Free and open to the public.
Presented by Cobb County Master Gardener Donna Kennedy, at East Cobb Regional Library, as part of the ongoing Gardeners Night Out presentation series of Cobb Extension's Master Gardener Volunteers of Cobb County.

Tuesday, August 14, 2012

Drought Still a Danger for Trees

In spite of recent rains, Cobb County is still experiencing Extreme Drought conditions, as shown on the U.S. Drought Monitor website of the National Drought Mitigation Center.  Conditions have been dry enough for long enough that many trees that have not been watered adequately are showing signs of drought stress.

Different plants will show the stress differently, but in general, leaves may curl, wilt, turn yellow or brown, or drop off completely. Maple trees, for example, tend to lose leaves from the ends of their furthest twigs, almost giving them the look of having just had a burr haircut. Since symptoms of drought stress can resemble damage caused by diseases and insects, calling the Extension Office to check for other possible causes of problems is a good idea.

Instructions for providing adequate water to trees are included in the section on irrigation in the UGA Cooperative Extension publication "Shade and Street Tree Care”:

"Apply water to mature trees after two to four weeks without normal rainfall. Water deeply and infrequently to recharge the root zone. Check the depth of water penetration by pushing a thin steel rod into the soil. The probe will push easily through wet soil but with difficulty through dry soil. Probe the soil two to three days after watering to determine depth of penetration, and make sure the water is reaching a depth of 12 to 18 inches. Allow the tree to absorb the water before the next irrigation."