Some weeks the phones are quiet in the Clemson Extension Master Gardener office. The volunteer Master Gardeners pass the time reading about their favorite gardening topics and chatting about their own gardening adventures.
This, however, was not one of those weeks. As summer temperatures have begun to rise, pests and diseases have started to encroach on Lowcountry homes and gardens. A flood of phone calls and emails this week revealed several common threads shared among Lowcountry residents.
This week, vegetable gardening problems and home invading insects are just two topics that seem to be on the minds of many, so I am sharing three of the questions that we recently encountered, along with the responses.
Q. Can you identify these insects? They were seen coming out of the shower drain in my guest bathroom. Help!
A. The client brought multiple insects preserved in alcohol to the county Extension office and so we were able to correctly identify the insects as termites. The homeowner reported a recent plumbing leak that may have led to moist, decaying wood under the home, which termites find palatable.
Fortunately, the leak had been repaired and the home was under a termite bond by a licensed South Carolina pest control company.
Since it is very difficult for homeowners to adequately treat termites, employing a licensed pest control service to treat and monitor for these insects is recommended.
For more information on what to look for when hiring a pest control company, read the Clemson University factsheet "Choosing A Professional Pest Control Company" at http://bit.ly/1s8IdqU.
Q. For the past several years we have grown peppers and tomatoes in containers on our deck. Most of the fruit has black, rotten, spots on the bottom. What is this? Can it be treated?
A. Blossom end rot is not a disease but a physiological issue in garden vegetables such as tomatoes, peppers, melons and squash. The condition is characterized by the part of the fruit farthest from the flower (i.e. blossom end) appearing black and rotten. Often, secondary fungal infections will turn the rest of the fruit into mush if not promptly removed.
Blossom end rot is caused by a lack of available calcium during fruit development. Factors influencing this problem include low levels of calcium in garden soil, sandy soil that dries quickly, or containerized gardens that are allowed to dry completely between watering. Interestingly, plants that have been over-fertilized often cannot take up calcium efficiently, which also leads to this unsightly condition.
To avoid blossom end rot in containerized garden plants, use fresh soil-less media each year. In conventional gardens, be sure to test soil regularly, make necessary pH adjustments, and amend the soil with compost.
Conserve soil moisture by adding 2 to 3 inches of organic mulch such as weed-seed free hay, pesticide-free grass clippings, pine straw, or chopped leaves to help retain soil moisture. Water plants regularly, preferably using drip irrigation or soaker hoses to avoid wetting foliage.
Q. The leaves of my squash plant have a white powdery substance on them. What is this?
A. When the temperatures and humidity rise, it is only a matter of time before the signs of powdery mildew appear on susceptible vegetables and ornamental plants. Members of the plant family cucurbitae (squash, melons and cucumbers) along with other edibles such as blueberries and pecans can be susceptible to powdery mildew.
Popular ornamental plants also can play host to the fungus, including azalea, dogwood, phlox, snapdragon, dahlia, zinnia, crape myrtle, rose, pyracantha, rhododendron, spirea, wisteria, delphinium, oak and English ivy.
Symptoms on squash plants begin with yellowing leaves, followed by the characteristic powdery white spores, and finally the leaves turn completely yellow or begin to brown and wither.
Squash planted early in the season typically produce fruit before the conditions become favorable for powdery mildew, so the best course of action is to simply remove and dispose of the diseased plants.
Commercial Vegetable Extension Agent Zack Snipes says it's not economically feasible to treat a few squash plants with a fungicide for powdery mildew. He explained that since they already have produced fruit, gardeners should remove them and plan for a new crop later in the summer.
Fortunately, most ornamental plants affected by the fungal disease rarely die but it is important to choose resistant varieties and remove affected leaves and branches when possible. Fungicides for specific ornamental plants also are available treatment options.
For a complete list of recommended fungicides for common landscape plants, see the Clemson Extension Home and Garden Information Center's factsheet "Powdery Mildew" at http://bit.ly/1qAuPr5.
If you have a home or garden question, contact your local Clemson Extension office or visit the Master Gardeners at one of the local farmers markets - just look for the "Ask A Master Gardener" table.
Master Gardener class
The Clemson Univer- sity Cooperative Exten- sion Service Master Gar- dener program will offer its next volunteer training course beginning Sept. 18.
Applications for the course are now being accepted online at http://bit.ly/SQzwBA.
All interested candidates must apply by the Aug. 8 deadline.
Due to road closures near the Clemson University Cooperative Extension Service office in Moncks Corner, the office will be open 8 a.m. to noon and afternoons by appointment only Monday through Friday.
Call the office at 719-4140 for an appointment.
Soil samples may be dropped off at the following locations:
Charleston County Office, 259 Meeting St., Charleston, 722-5940
Dorchester County Office, 201 Johnston St., St. George 832-0135
Summerville Master Gardener Office, 1105 Yancey St., Summerville, 285-2180 (9 a.m.-noon)
Summerville Farmer's Market, Main Street 8 a.m.- 1 p.m. Saturday, April- October