I have a question about bark mulch, chips, etc. I’ve been told that you can’t put it around trees and shrubs so that it touches them in any way because it will kill them. Is that true? I thought it was good to put that around them in order to keep down competing grasses and to hold moisture.
What you have been told is true. You want to keep any wood mulch away from the base of plants. Small shrubs, perennials and annuals need about six inches of breathing room, while trees prefer about a foot or two. This prevents basal rot and discourages rodents and insects from nesting around the crowns of your plants.
I usually apply 2 to 3 inches of mulch to my flowerbeds. I do this in the spring and again in the fall after the ground freezes.
I like wood mulches because they break down and add nutrients to the soil but this also means needing to top-dress my beds in mid-summer.
Many people ask me about the differences between the wood mulches. I find that it is mainly a matter of taste and what is readily available in your area. Shredded mulches tend to mat together and therefore stay put more easily that the chips or nuggets. Wood mulches can attract rodents and insects. If this is a concern for you try a cedar mulch or look into inorganic mulches.
A final concern many people have is fungus. Regardless of quality wood mulches sometimes develop fungus, especially when the weather gets steamy. Simply remove infected bark and spot spray area with a fungicide.