It was cold out there! by Bill Hayes

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I checked the Aiken Master Garden Almanac and sure enough, it said that our coldest annual temperatures are usually between December 30th and January 20th. We have had a very cold two weeks and the results could be a shock to some of our turf grasses in the spring. Between January 3rd and January 14th, we had consistent low temperatures between 19 and 26 degrees, F. The daytime highs were no bargain either and averaged just a hair above freezing. This is bad news for grass, especially common centipede and some varieties of St. Augustine. We often hit freezing temperatures but most of the time it will only be for a few hours during the night. The recent cold snap kept temperatures below freezing for almost two full days. The cardinals that frequent my birdbath were using their beaks as ice picks to get some water. So what will happen to our lawns? Only time will tell but prepare for the worst. Last year was a bad year for turfgrass “winterkill” and the temperatures were not as bad as what we just experienced. For more information, plan to attend the “Lunch Box” seminar on lawns at the Clemson Extension office on February 15th starting at noon. This will be the first of a series of seminars on a variety of subjects.

Let’s answer some of the recent questions that came into the Extension office:

Do moles hibernate? I haven’t seen onerecently.

No, they don’t hibernate but the cold temperatures send them deeper. Moles follow the food supply and worms are their favorite food. Worms don’t like cold or dry soil so they find a layer that suits them for temperature and moisture. In the winter that level may be two to three feet below the surface. The moles follow them to that level and don’t produce the surface tunnels and volcanoes that you normally see in the spring and fall. Dry, hot weather in the summer also drives them lower unless you are irrigating heavily.

Should I use a “weed and feed” fertilizer for my lawn in February if it warms up?

This is a very bad idea! First of all you want to time your pre-emergence weed killer with the germination soil temperature, which is 55 degrees, F for crab grass. Normally, that would be around March 15th to March 30th. Putting a weed killer down too early may allow the product to degrade before it is needed. Secondly, never put nitrogen on the lawn until the first to second week in May. Early applications can damage the lawn if we get an early warm-up and a late frost or freeze. To check 4″ soil temperatures, go to http://www.georgiaweather.net and click on Dearing, which has conditions similar to ours. Then click on “current conditions” and read down to the 4″ soil temperature. Remember that that the 55 degree temperature should stay constant for 24-48 hours so an early reading on a warm day in January might read 55 degrees but will only last a short time.

How often should I sharpen my lawn mower blade?

I like to sharpen a blade after every third or fourth mowing. I know that very few people do that but consider the problems if you use a dull blade. Instead of making a nice clean cut, a dull blade will bludgeon the grass, make a jagged cut and allow an opening for disease. It will also make the lawn look bad. Our sandy soils mix with air and other lawn debris in the lawn mower cutting area and create a strong turbulence that can dull a sharp blade very quickly. It will surprise you to look at a lawn mower blade under magnification. You will be amazed to see large  gouges in the blade from the sandy soil. Buy a spare blade and a good file to keep it sharp. You will be happy with a better lawn appearance.

Does my lawn need water during the winter?

This will depend on the amount of natural rainfall we receive. Our lawns and shrubs need moisture to remain healthy and that includes winter applications although they don’t need as much.  Give the lawn about an inch of water per month, which includes rainfall. Check your planting  beds to see if your soil is moist. If not, make sure the plants get a drink every couple of weeks. Most damage in the winter comes from dehydration caused by very cold dry temperatures, wind and a lack of rain.

Last year my oak trees had a fungus and the leaves had blisters. Are they dying?

Oak leaf blister was a big problem in Aiken last year. Oak leaf blister caused by the fungus Taphrina caerulescens is a common disease affecting  many species of oaks. Members of the red oak group are particularly susceptible to infection. Disease development is favored by cool, wet springs and, in years when such conditions occur, noticeable leaf deformity results. White oaks are rarely infected, even in years with cool, wet springs. Heavy infections of red oaks impair their appearance but do not endanger the tree health. If your trees are infected, clean up fallen leaves and discard them. Spraying a tree is a job for a professional and must be done prior to bud break.

Late January and throughout the month of February is the time to set out rose bushes. Choose a sunny spot in the garden with welldrained soil. You don’t have to create a bed dedicated only to roses. Consider planting them with perennials, annuals or flowering shrubs so they become a part of the landscape. When selecting a rose bush, avoid those plants that are showing evidence of new growth, since the winter weather may damage the new plant. Also make sure the canes are a healthy green color.

Now is the time to cut back winter-damaged, unattractive liriope foliage. Avoid tipping the new growth or there will be brown edges for the year to come. If you do it now before growth begins, you can use a string trimmer or the lawn mower set at its highest setting. Use a sharp blade.

Don’t include French or big leaf Hydrangeas (Hydrangea macrophylla) when you are doing your pre-season pruning. If you do, you will cut off flower buds that formed last summer. So let them bloom and then prune them if they need it. This is also true for azaleas.

Don’t forget that you can call in your questions to 803-649-6297, ext. 122 or email us at aikenmastergardener@hotmail.com.