Powdery mildew was reported on rosemary this week.
In addition to rosemary, the characteristic white spots of powdery mildew usually first appear first on the upper surfaces of the lowermost leaves of many types of plants such as non-stop begonias, calibrachoas, dahlias, asters, phlox, monarda and other susceptible crops. Stems and flowers may also become infected.
Intumescence is an abiotic disorder which produces small blisters on leaf surfaces. Severe cases can result in defoliation. Certain plants are especially susceptible to intumescence; these include members of the Solanaceae such as Ipomoea, peppers, and tomatoes, and Cuphea in the Lythraceae family. The symptoms resemble and are often mistaken for edema (or oedema), but their development is distinctly different. In addition to the genus of the afflicted plant, the location of the symptoms is also helpful in distinguishing intumescence from edema.
It is that time of year for extreme temperatures and weather conditions. Monitor the weather forecast and avoid moving cold tolerant annuals and herbaceous perennials outdoors if a hard frost (colder than 28°F) is predicted at any point within at least three nights of when plants would be put outside. Avoid placing plants in low-lying areas because frost will more likely settle in these areas. Be prepared to cover plants if temperatures go below 28°F.
Here are some tips for handling plugs, media and tips for transplanting.
Upon arrival, open and unpack the boxes immediately and check the physical condition of the plants. Inspect plants for root and foliar diseases and for insects and mites. Report any damage or discrepancies immediately to your supplier (most companies want to hear within 24 hours). Take a picture if there is a problem!