Abundant, frequent rains promotes disease problems. We are seeing leaf spots on vegetables, annuals, and perennials; these should be sprayed with labeled fungicide products at the first sign of symptoms. This won’t cure the infected leaves, but it will help prevent the infection from spreading. Fruit trees are already showing leaf spots (apple scab on apples, black rot on grapes) and fruit (brown rot on peach). If you want decent quality fruit, you MUST spray with a fungicide or orchard spray on a weekly basis. Refer to Purdue’s “Managing Pests of Home Fruit Plantings” for specifics: http://www.extension.purdue.edu/extmedia/ID/ID-146-W.pdf.
Our wet spring is promoting lots of weed problems this year. Yellow nutsedge loves moisture, and is already coming up in area lawns and landscape beds. By the time this plant is clearly visible, it’s already too late to get good control. Sure, you can burn it back with herbicide, or you can even pull it out by the roots. But nutsedge reproduces by producing underground tubers, which get left behind when the plant is pulled. You can spend hours pulling this stuff, and it will come right back. Control is achieved by using herbicides in early May (and repeated about 6 weeks later), just as the leaves are appearing. More information here: http://www.extension.purdue.edu/extmedia/AY/AY-19-W.pdf.
Lots of rain also means lots of mushrooms popping up in our lawns and landscape beds. The majority of these mushrooms are not edible, and a few are toxic. A little further down in this Alert is an announcement about a mushroom identification workshop coming to Evansville in July.
One last thing: just because it rained a lot this spring, doesn’t mean you don’t need to irrigate for the rest of the summer. The roots of our annuals and perennials are only a few inches deep, and the upper few inches can dry out with a week of warm, sunny weather. In addition, many plants survive soggy soils by growing shallower-than-normal roots, so that they can get oxygen. This makes these plants even more prone to drought injury once the rains stop. Be sure to check the soil of your gardens every couple of days, and provide one heavy soaking (one inch of irrigation) per week if we don’t get that much rain.