DALY: Answering questions about winter lawns, Leyland cypress and frost protection

Tim Daly

Gardening columnist Tim Daly answers questions from readers:

Question: My lawn care company wants to apply fertilizer and lime to my bermudagrass lawn. They also recommend pre-emergent herbicides. Is right now a good time for these applications?

– Lois, Snellville

Answer: Lois, fertilizers should not be applied to bermudagrass or other warm-season grass lawns such as zoysiagrass and centipedegrass. The grass is dormant and will not absorb it. Any rainfall could potentially wash the fertilizer into water bodies causing pollution. It could also cause the lawn to come out of dormancy too early in the spring, which may lead to cold damage if we have a late season freeze.

Does the lawn need lime? That all depends on what the current pH of the soil is. You should consider having your soil tested for pH and fertilizer needs. UGA Extension Gwinnett offers this service. You can submit your soil samples for the cost of $8 per sample at the Extension office, located at 750 South Perry St. #400, Lawrenceville, GA 30046.

Our office hours are Monday through Friday, 8 a.m. to 5 pm. Regarding pre-emergent herbicides, you should wait until the middle to latter part of the month to have them applied. For existing weeds, you will need an application of a broadleaf herbicide.

Q: My Leyland cypress has branches that are dying, and the needles near the ground are dying? What can I do to save the tree? I value the privacy they offer. Are other plants better suited that will provide screening?

— Tom, Sugar Hill

A: Tom, Leyland cypress trees are better adapted to cooler climates. In our area, the trees are frequently planted too close together. They can reach a height of 50 to 60 feet and a spread of 15 to 20 feet. Thus, if they are planted five feet apart, the Leyland growth pattern will crowd out each other causing them to suffer and be more susceptible to diseases. From the description of the issues you are having, they probably have fungal canker disease, which no treatment exists other than pruning out the infected branches. The needles at the bottom are being shaded out, and will not regenerate new growth. Several alternatives can provide the screening you desire. Examples include wax myrtles, several hollies including ‘Nellie R. Stevens’, American and Foster hollies, Canadian hemlocks, and southern magnolias.

Q: I am concerned that my garden plants may suffer from freeze damage, particularly my vegetable garden, which has collards, broccoli, carrots and a few other ones growing. How can I protect these plants?

– Alice in Lilburn.

A: Alice, the good news is most of our garden and landscape plants are tolerant to the hard freezes we can get in our area. Certain plants can undergo minor damage from extreme cold, such as rosemary, gardenias, and some hollies. However, they will recover if healthy. The vegetable plants are hardy but can suffer damage if the temperatures fall below 20 degrees. Fig trees are particularly sensitive and can be killed back to the ground.

If these temperatures are forecasted, you should cover the plants with plastic, thick cloth or ‘frost blankets,’ which can be purchased at local garden centers. When buying plants that will grow year-round in your garden, make sure they are labeled for growing in USDA Plant Hardiness Zone 7b.

The UGA Extension Gwinnett 2019 annual plant sale is underway. Many excellent plants are available at affordable prices. Choices include blueberries, gardenias, ferns, goji berries, and many others. To obtain an order form, one can be downloaded from the Extension website at www.ugaextension.org/gwinnett, or you can have one mailed to you by contacting the Extension office.

Timothy Daly is Agricultural and Natural Resource Agent with the UGA Extension Gwinnett. He can be reached at 678-377-4010 or tdaly@uga.edu