Farming

Powdery mildew is probably the most common garden fungus around.  
It is not too terribly picky about where it spreads, it likes humid weather, thrives in the heat of the summer and is hard to control once it has started.  
The trick here is to prevent it from happening by proper plant selection, spacing, pruning and treatment before it spreads.
Powdery mildew is caused by several different fungi, I won’t bore you with their names because they all act the same way.  

It seems that we have been spoiled: A decade of mostly mild winters has led us to believe that all those borderline hardy plants would never get knocked back by a cold winter.
Well, I have seen quite a few crape myrtles, figs and French hydrangeas that are struggling to come back on old wood.
Fear not, however, because these plants are root hardy and will sprout new growth from the roots.

There are some plants that demand good drainage:  taxus, coreopsis, gaillardia and penstemon, to name a few.  I have lost them all because they were poorly sited in the garden but now that I know where water is slow to drain I know where to plant those trees, shrubs and perennials that like wet environments.  There is an upside to poor drainage for some plants, just be sure that water is available when Mother Nature doesn’t deliver.