This is a common mistake that I notice around trees. Mounding mulch too close to a plant’s stem or a tree’s trunk is another common mistake. This is a common practice of public landscapers. It even has a name - mulch volcanos. Besides leading to the two problems listed above, mulch volcanos offer safe harbor to insects and they hold moisture next to the stem or trunk, with can lead to rotting or fungal diseases. Always keep mulch an inch or more away from the actual plant.
Death by mulch is usually a slower process than over watering, but if you think you’re doing everything else right and your plants still aren’t happy, check your mulch depth. Rake it out and make sure water is able to sink through and get where it needs to go. Every plant is different. Every garden is different. The best way to care for your plants is to keep a close eye on them and catch problems early. Luckily that just means walking or working in your garden regularly, something we already do.
Taken from http://gardening.about.com/od/gardenproblems/fl/How-to-Kill-Your-Plants.htm?utm_content=7337008&utm_medium=email&utm_source=cn_nl&utm_campaign=gardening&utm_term=
Till next time this is Becky Litterer from Becky's Greenhouse, Dougherty Iowa