Q&A with Eli Snyder- Wireworms and Pruning Questions

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With the recent stretch of warm temperatures, a number of timely questions have come into the N.C. Cooperative Extension, Caldwell County Center, as folks start thinking about gardening again. I will share a few of these questions with you today.

Question: How do I control wireworms in my home garden?

Answer: Wireworms are the larval form of a click beetle. Click beetle adults are active during summer months. Females will deposit eggs in grassy areas. Once eggs hatch, the larvae spend the majority of their life in the soil, where they feed and go through multiple larval stages. They may take 2-5 years to reach their mature larval stage before pupating and becoming adults. Wireworms move vertically through the soil profile, and are closer to the soil surface when temperatures average 70°F. There are three species of click beetles and wireworms that may be pests in the region.

They feed on plant parts that are underground, such as plant roots and tubers, and are known for causing damage to potatoes.

Wireworm

Wireworms are the larval form of a click beetle. They are a common pest of potato. Photo credit: Katja Schulz / CC BY 2.0

They can also damage newly planted seeds, bulbs, or other root crops like carrots. When they feed, they create tunnels- damaged potatoes have small holes on the surface, and when cut open, a tunnel is visible. Because females lay eggs in grassy areas, wireworm damage tends to be worse in potatoes planted in fields recently coming out of sod. Once wireworms are in an area, they may be problematic for several years. They are more common in lower lying, wet areas.

To avoid wireworm damage, don’t plant root crops in areas that have recently been in sod. Practice crop rotation, and choose well-drained sites for these crops. That will reduce problems with root crops rotting in wet years, as well. Make sure your garden gets enough water, because during dry times, wireworms may seek out potatoes for extra moisture in addition to food. Harvest potatoes according to the recommended maturity date of the particular variety you grow. Wireworm damage will increase the longer potatoes are left in the field. Taking these steps will help you avoid wireworm problems. In areas where wireworms are consistently challenging, applying a soil-applied granular insecticide with the active ingredient bifenthrin (such as Hi Yield or Eight) before you plant may help. There are also several species of beneficial nematodes that can be applied to the soil, and have shown potential to control wireworms, but research is still limited on these.

Question: When do I prune hydrangeas?

Answer: There are a few species of hydrangea, and the timing of pruning depends on which species you have. Some hydrangeas develop blooms on new wood, and others flower on old wood that grew the previous year. Hydrangea macrophylla, known as bigleaf hydrangea, is the hydrangea that varies in color- pink to blue- depending on soil Ph. These along with lacecap and oakleaf (H. quercifolia) hydrangeas bloom earlier in the season, on old wood. They should be pruned just after they flower, as later in the season they begin developing buds for next year’s blooms. Peegee hydrangeas (H. paniculata) and smooth hydrangeas with white flowers (H. arborescens) bloom later in the summer on new growth. These can be pruned during late fall or winter. For photos of the different varieties and tips on pruning, see the Pruning Hydrangea Guide.

Question: When do I prune my blueberries?

Answer: Mid or late winter is a great time to prune blueberries as well as other fruit such as blackberries, grapes, and tree fruit. There are several upcoming workshops that may be of interest to those growing fruit at home:

Blueberry Pruning Workshop at Campbell’s Berry Farm

Tuesday, February 19, 2019, 1–3:30 p.m.

The workshop will be led by NC State Extension Blueberry and Muscadine Specialist, Dr. Bill Cline.

Blueberry pruning

Pruning berries and tree fruit in winter leads to larger fruit and healthy plants, but must be done correctly for desired results.

Campbell’s Berry Farm is located in Bethlehem off of Highway 127. The address is 27 Tracy Bolick Lane, Hickory, NC. To register, please call 828-632-4451.

Tree Fruit Workshop at N.C. Cooperative Extension, Alexander County Center

Wednesday, March 6, 1–4 p.m.

The class will be taught by NC State Extension Tree Fruit and Pecan Specialist, Dr. Mike Parker.

Address: 376 1st Ave SW, Taylorsville, NC. To register, please call 828-632-4451.

Pawpaw Class at N.C. Cooperative Extension, Caldwell County Center

Monday, March 11, 2019, 5:30–7: 30 p.m.

Learn to grow one of our native fruit trees, the pawpaw. The class will be taught by pawpaw enthusiast and NC State Extension Area Agent, Craig Mauney.

Location: 120 Hospital Ave NE, Suite 1, Lenoir, NC. To register call 828-757-1290.

If you are looking to add to your edible landscape at home, don’t miss our 2019 Edible Plant Sale. We are accepting orders now through March 4. The pickup date is March 15. For more information in any upcoming classes, our Edible Plant Sale, or winter garden chores, contact the N.C. Cooperative Extension, Caldwell County Center at 828-757-1290, Monday-Friday, 8–5 p.m.