Be careful about what you wish for comes to mind this week – we wanted rain to help the very dry May conditions, and we certainly got rain. So far in my garden I have had over 3-inches and the forecast for the next 10 days is more of the same – storms which will increase the rain on the garden. So, we have uncomfortable conditions for the start of summer and heat plus humidity creates the perfect environment for many mildew and fungal issues.
There are numerous fungal pathogens some of which are host specific and some are not. Look for a powder or dust of material coating the leaves of a plant which can spread rapidly across a plant. Everything from crepe myrtles to lawn turf can be affected by fungus. Basic good cultural habits can minimize the issues, but sometimes nature wins so monitoring is important. Always pick up fallen leaves from a shrub that show disease leaves. Put the leaves in the trash not compost.
For perennials and shrubs that you want to enjoy for years to come, take note of which ones are most susceptible to problems in summer. Phlox, monarda, roses and crepe myrtles all tend to be affected and should be watched carefully as soon as the sauna conditions arrive. Look at the plant as a whole and inspect both the top and underside of the leaves.
In the vegetable garden, the squash family are notorious for developing white powdery mildew and this year that is going to be almost a certainty. In a settled plant, with just one or two leaves that show signs of developing the mildew just take those leaves off and discard in the trash. For a more widespread fungus issue, treat with a fungicide. Always check the label to see that it is labeled for edibles for the plant that you are treating.
Problems can also occur on plants that are crowded together. Perennials that looked to be nicely spaced in spring have grown much larger and wider to look mature and filled in from a distance but on closer inspection you may find areas where mold has started. Likewise, raspberries and blackberries send up new shoots every year and those too can create areas of poor air circulation.
So, assume that you will probably have at least something this year that will get a mold/fungus problem. The key is to check the garden daily and look carefully at the leaves, both top and bottom so that you can treat the problem before it spreads too far. There are lots of commercial treatments, but my personal preference is for a Neem product. Neem can also be used for aphids and other small issues that you have as well.
Let’s hope that this hot and humid weather ends soon, and our gardens can dry out properly. Also remember to turn your automatic watering systems off for a while.
Kate Copsey is a garden author, writer and speaker now living in eastern Orangeburg County. Her book “The Downsized Veggie Garden” is available from bookstores everywhere as well as her webpage www.katecopsey.com.