Month: May 2011

No matter where you are in the Cincinnati area, April was a month for the record books and a month which had a profound effect on local horticulture. 

April rainfall amounted to 13.52 inches at the Cincinnati-Northern Kentucky airport and 14.26 inches at my Cheviot 0.9SSE location.  Either way, this smashed the old April rainfall record of 9.77 inches set in 1998 and challenged the all-time record for any month of any year of 13.68 inches set in January of 1937.  This followed the severe drought which plagued our area in the summer and fall of 2010, not to mention the 7 month drought in 2007 and the multi-month drought in 2008. 

Over the winter, we saw many dead and stressed evergreens as a result of the drought.  While the immediate effects of drought are obvious, the long term effects of drought can be profound and long lasting, actually compounded by excessively wet weather.  Roots require access to both moisture and oxygen.  Drought robs roots of adequate moisture, but excessive moisture fills soil pore spaces and displaces soil oxygen, creating root killing anaerobic soil conditions. 

Prolonged rainfall greatly increases disease pressures on trees and shrubs.  Continual rainfall makes it more difficult for us to treat while simultaneously providing ideal conditions for disease to take hold.  The disease triangle demonstrates how the disease itself, a susceptible host plant, and adequate moisture must all be present for plant diseases to take hold.  In many cases, the plant is always susceptible and the disease spores are always present, so moist years will be big years for plant diseases. 

You may see us treat even when rain is forecast.  This is because fungicides prevent disease and disease spread as opposed to curing it.  Therefore, you need the fungicide to be present on the susceptible plant when the next rain comes.  Additives in the treatment help to prevent it from being washed away.