Plant Now for Fall and Winter Harvest

Just because it’s fall doesn’t mean the vegetable gardening season is over. You still have time to plant crops that will keep you harvesting produce through the winter and on it to spring.

In the coastal plain, many cool season crops can be planted in September. Brassicas like broccoli, cabbage, cauliflower, collards, kale, and kohlrabi can be planted through the middle of September. Keep an eye out for caterpillars on these crops. You can protect your plants with row covers or control caterpillars with products containing Bt or spinosad, if needed.

Root crops are another great fall option. Plant beets, radishes and turnips through the middle of September while parsnips and rutabagas can be planted through the end of September. These vegetables will hold well under cool conditions and can be harvested as needed.

Plant leafy greens like lettuce, arugula and mustard for a quick harvest. You can harvest baby greens when the leaves are 4-5 inches high. Trim the leaves off with a pair of kitchen shears while leaving the growing point intact. These plants will resprout several times for multiple harvests.

Cool season herbs like dill, parsley and cilantro can be direct sown or set out as transplants in September and will stay green well past the first crop. Harvest as needed for fresh use. Consider planting garlic and onions in October. These crops will be ready to harvest next spring. Choose short-day varieties of onion like Grano or Texas Supersweet.

Sample your soil now to determine fertilizer needs for next growing season. In our area, gardeners should test the soil every 2-3 years. Make sure your soil samples are submitted to NCDA&CS prior to Thanksgiving to avoid peak season soil sample fees.

Dividing Perennials

Mid-September through October is a great time to divide perennials in our area. Dividing perennials promotes plant growth while allowing you to easily create more plants. Vigorously growing perennials like chrysanthemums and asters may need to be divided every season or two, while slower growing plants may never need division.

Many perennial plants benefit from regular division but don’t divide on a time schedule, let the plant’s growth habit dictate whether you need to divide it. Perennials need to be divided when: flowering is reduced or flowers get smaller, the center growth dies out but there is growth around the edges, bottom foliage is sparse, the plant loses vigor, the plant flops over or requires staking or it has simply gotten too large for its space in the garden. Of course, even if your plant is growing and blooming well, you may choose to divide it to create more plants for your garden or to share with friends. 

Perennials should not be divided while they are in flower. Flowering demands a lot of energy from the plant and you do not want to stress a plant by dividing it at the same time. The general rule of thumb is to divide spring-flowering plants in the fall and fall-flowering plants in the spring. Good options for fall division are spring blooming bulbs like daffodil and amaryllis, daylilies, hosta, lamb’s ear, echinaceae, and black-eyed Susan. Wait until spring to divide your cannas, chrysanthemums and ornamental grasses.

For details about dividing perennial plants, check out this excellent reference:


· http://www.clemson.edu/extension/hgic/plants/landscape/flowers/hgic1150.html

Emerald Ash Borer Moves Towards Southeastern NC

Emerald Ash Borer. Photo: David Cappaert, Michigan State University, Bugwood.org

Emerald ash borer (Agrilus planipennis, or EAB) is a metallic-green beetle that bores into ash trees (Fraxinus species), ultimately killing them. This beetle is not native to the United States. It is originally from Asia and was first detected in the US near Detroit, Michigan in 2002. Since then, it has spread to Quebec, Ontario and twenty-five states in the US.


Emerald ash borer was first detected in NC in 2013 in Granville County, and later in Person, Vance and Warren counties. In 2015, EAB was found in eight new NC counties – Wayne, Franklin, Wake, Durham, Graham, Johnston, Orange and Wilson. The detections in Johnston, Wilson and Wayne counties brings EAB one step closer to Onslow so we need to be aware and stay on the lookout for this insect.

Quarantine area for emerald ash borer in North Carolina

Counties under Quarantine for EAB
Durham	Johnston	Wake
Franklin	Orange	Warren
Graham	Person	Wayne
Granville	Vance	Wilson

EAB lay their eggs on the bark of ash trees. When the eggs hatch, the larvae bore through the bark and feed in the vascular tissue of the tree. This feeding causes serpentine tunneling marks, known as feeding galleries, which are found under the bark of infested trees. This damage disrupts the movement of nutrients and water within the tree, eventually killing the tree. Outward symptoms of EAB in ash trees include a general decline in the appearance of the tree, such as thinning from the top down and loss of leaves. Clumps of shoots, also known as epicormic sprouts, may emerge from the trunk of the tree and increased woodpecker activity may be noticed.

Emerald ash borers overwinter as larvae within the tree. Adult beetles begin to emerge from May to June and can be found in the summer months. The adult beetle is ¼ to ½-inch long and is slender and metallic green. When the adults emerge from a tree, they leave behind a D-shaped exit hole. (Please note that EAB are not the only beetles that leave a D-shaped exit hole in trees. Species of native buprestid beetles leave a similar shape hole when they emerge from host trees.)

	Serpentine galleries under bark William M. Ciesla, Forest Health Management International, Bugwood.org
	D-shaped exit hole David Cappaert, Michigan State University, Bugwood.org

Adult EAB can fly at least ½ a mile from the tree where they emerge, but are more commonly spread when humans move infested materials such as nursery stock, logs, and firewood into uninfested areas. For this reason, all counties with detected EAB are under a quarantine that restricts the movement of ash nurserystock, ash plant material (trees, limbs, branches, lumber, bark chips) or hardwood firewood of any species. Businesses affected by this quarantine can apply for a compliance agreement with the North Carolina Department of Agriculture and Consumer Services (NCDA&CS).

The NCDA&CS and NC Forest Service are working with the US Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) to conduct an ongoing survey for EAB throughout the state. They are using a combination of purple prism traps and green funnel traps which are placed in ash trees in the spring and monitored throughout the beetle’s flight season for EAB then removed in the fall.

An interesting biosurveillence strategy is also underway. Biosurveillence is the use of living organisms to detect other living organisms – think of bomb-sniffing dogs being used to find hidden explosives. In this case, researchers are using native groundnesting wasps that naturally feed on wood boring beetles. These wasps, specifically the species Cerceris fumipennis, hunt native beetles and will hunt EAB if they are available. The wasps then bring their prey back to their burrow to bury it. By observing these colonies and collecting some of the prey the wasps bring back, scientists are able to monitor for EAB. This is currently one of the most promising strategies to monitor for EAB. Citizens can support this effort, WaspWatcher, by identifying and monitoring Cerceris fumipennis colonies on their property.

   Cerceris fumipennis female with prey. Photo courtesy of WaspWatcher Program

Homeowners and landowners are encouraged to report any symptomatic activity in ash trees to the NCDA&CS Plant Industry Division hotline at 1-800-206-9333 or newpest@ncagr.gov. The pest can affect any of the four types of ash trees grown in the state. Researchers in Ohio have found EAB also infests white fringetree (Chionanthus virginicus). This small native tree is widespread in North Carolina and another potential host. So far, there is no evidence that EAB will infest Chinese fringetree (Chionanthus retusus).

For additional information about EAB:
http://www.ncagr.gov/plantindustry/Plant/entomology/EABProgram.htm

Details of the quarantine and compliance agreements can be found here:
http://www.ncagr.gov/plantindustry/Plant/entomology/EABFAQ.htm

For information about Cerceris fumipennis and the WaspWatcher Bioserveillence Program:
http://www.cerceris.info/