With the recent warm spell, there is hope that spring is just around the corner. Pretty soon the temperatures are going to rise, and the landscape will come alive with beautiful spring flowers and the bane of every gardener’s existence: weeds. Are your landscape beds ready? If you are like me — the perpetual procrastinator — then the answer is probably no. So now is the time to take one of these gorgeous days and get outside to do some yearly landscape maintenance.
The first line of defense against those pesky weeds that come back each spring and summer is mulch. It is also fairly inexpensive, “green,” and easy to use. Mulch eliminates most of the sunlight weed seeds need to germinate and establish seedlings. It is recommended that you use a 3-inch to 4-inch thick even layer of mulch around trees, shrubs, and inside flower beds. Mulch can even be applied right over top of your perennial bulbs. This layer should extend to the drip-line, which is the edge of the tree’s branches and of large shrubs, but should never touch the trunk, or base, of any plant. The mulch helps to control weeds and provides a “blanket” to the fine roots, giving much-needed warmth and moisture.
Mulch comes in different textures, colors, and substances. Pine straw, pine bark, hardwood bark, cedar chips, and even red mulch are all available from your local garden supplier. When selecting mulch, think of the look you want to create, not of the price or makeup of the mulch. Pine straw is readily available in this area, and once settled, it will not move. Hardwood mulches decompose quicker than others. Chunky mulches, such as pine bark nuggets, tend to wash out with heavy rains and will have to be replaced more frequently. So which one is the best to use? From pine straw to that ostentatious red mulch, they all control weeds just the same.
So, what happens to the mulch year after year? As the weather changes over the course of the year, moisture and heat will build up within the mulch layer. This warm, moist environment is not only the ideal place for fine feeder roots of plants, but it begins to break down and “compost” the mulch. As it breaks down, it will turn into organic matter and provide a nutrient source for the plants. Each type of mulch will cause different changes in the properties of the soil when it breaks down, so be sure to complete a soil sample each year to check for changes in the soil pH and nutrient content. One example of this is the decrease in pH as pine needles decompose. If the mulch is applied each year, the layer of rich organic matter will increase, and you will have healthier and happier plants.
Now before you go out in your yard and start piling on the mulch, let us remember one important thing — just because a 3-inch layer of mulch works well does not mean that a 6-inch layer will work even better. Those volcanoes of red mulch that extend 2 feet up the maple tree’s trunk will definitely catch your eye. But three years down the road, do you really want to replace a tree that cost $150, because the trunk began to decay and die?
So hurry up, get out there and mulch away. But before you walk back in the house and call it a day, stand back and take a look at your handiwork to make sure you did not go overboard. If you have any questions, comments, or would like more information about any of the principles discussed in this article, please contact at 910-671-3276 or by e-mail at Kerrie_Roach@ncsu.edu, or visit our website at robeson.ces.ncsu.edu.
Kerrie Roach is an horticultural Extension agent at North Carolina Cooperative Extension, Robeson County Center.