August 13, 2021
Juglone is a chemical that inhibits the growth of certain plant species. When plants produce a chemical that prevents the growth of other plants, it is called allelopathy.
Control of weeds in the vegetable garden is important. These unwanted plants are strong competitors for available water, nutrients, and sunlight and can reduce yields when not controlled.
A year after the derecho, we lost so many beautiful trees while others lost limbs. We always remind oak lovers to avoid unnecessary pruning from April to July to minimize the risk of Oak wilt transmission. We had questions at the Plant and Insect Diagnostic Clinic from oak caretakers wondering if their derecho injured trees may be infected with oak wilt after the derecho.
With summer comes lilac leaf spots; at the plant clinic this year, we have seen the usual fungal pathogen Pseudocercospora causing leaf spots and blight (rapid death). Historically, Septoria leaf spot and powdery mildew also contribute to leaf blight, and in some cases, to abundant leaf drop. Environmental conditions, humidity, and stressors like drought, shaded locations, or lack of proper pruning could be exacerbating these problems.
Emerald ash borer has been found in Calhoun, Winnebago and Worth counties for the first time.
A new integrated pest management podcast from Iowa State University Extension and Outreach is now open to listeners interested in learning how plant science research impacts everyday life.