Mulch can be a miracle worker in the garden. It covers bare soil, which improves the appearance of the garden bed. It also helps smother out weed growth while preventing moisture loss from evaporation. So how could one go wrong when mulching? Unfortunately, there are some mulching mistakes that can cause major damage to your plants. Knowing what they are is the key to avoiding them.
#1: Using the wrong type of mulch
Not all mulches are created equal. Stone or pebble mulches, for example, should only be used around perennial plants that prefer drier soil, such as lavenders and sages. You must also place a fabric underlayment beneath the stones, since otherwise they will work into the soil. Pine straw mulch is best suited to use with acid-loving plants, such as evergreens and some flowering plants, like lilacs. Larger long-lasting mulches, like wood chips and bark, work well in flower gardens, while straw is a preferred option in vegetable beds where you want everything to decompose by the end of the season so it can be tilled in the following year.
#2: Smothering the stems and trunks
No matter what type of mulch you choose, applying it too deeply around the base of a plant can lead to disaster. Mulch traps moisture, which is great for the soil but can cause plant stems and bark to rot. It can also provide cover for over-wintering pests, which will chew on the bark and stems of woody plants for nutrients during the winter months. Always pull the mulch back from the base of the plants so it doesn't rest directly against them.
#3: Not paying attention to the depth
The depth of the mulch is also important. Applying a too thin layer doesn't do much good because moisture will still evaporate and weeds will still encroach on the bed. A too-thick layer, though, can smother plants or create a barrier against moisture and nutrients penetrating through to the soil. The ideal depth is about 2 to 3 inches. This will settle as the mulch naturally decomposes, so you will need to replenish your mulch every year. This is generally done in spring, but you may want to do it in fall if you have cold winters and want to provide insulation for perennial plant roots.
For more help with properly applying mulch to the garden, contact a landscaper or mulching service in your area.