The Benefits of Mulch

— Written By

Q:  Should I mulch my landscape beds now?

 A:         One can apply mulch anytime during the year, but now is a great time because it is easier to apply mulch before all our plants (and weeds) take off for spring. Plus, it is a great time to be outside considering the wonderful temperatures we have been enjoying. Mulch is one of the best ways to control those pesky weeds in the landscape. Along with controlling weeds, there are several other benefits of mulch. Here are some of the benefits that mulch provides in the landscape:

  • Controls weeds
  • Conserves soil moisture
  • Prevents soil erosion or crusting
  • Reduces chances of soil-borne diseases from splashing onto plant foliage

For landscape beds, mulch the entire area. For individual plants, such as trees, the mulched area should extend at least 3 to 6 feet out from the base of the plant. The mulch should be pulled 1 to 2 inches away from the base of the plants to prevent bark decay. Mulching around trees will not only save the trouble of trying to dunk under tree limbs while mowing but will prevent damaging plants with lawn mowers and weed trimmers.

A good layer of mulch should be 2 to 4 inch deep. Although mulch is a good thing, you can have too much of a good thing when it comes to mulching. A deep mulch layer can result in the roots growing into the mulch and not growing into the soil.

It is not necessary to remove the mulch when you fertilize. Apply the fertilizer over the mulch and the nutrients will move with water to the root in the soil below.

Types of Mulch

There are two main categories of mulches: organic and inorganic. Examples of organic mulches are pine straw, pine bark nuggets, and compost. Organic mulches will decompose over time, often adding small amounts of nutrients into the soil and improving the soil. Organic mulches, however, do not add enough nutrients to replace fertilizer.

Buy mulch that is weed-free to avoid adding more weeds to the landscape. Do not use any mulch that has a smell of vinegar, ammonia, or sulfur. This smell means that the mulch went through anaerobic (low oxygen, high moisture) decomposition and has become very acidic, which can cause a loss of those prized landscape plants. Fresh sawdust is not recommended for mulch because it has not begun to decompose. Sawdust that is not yet decomposed that is used as a mulch will take away nutrients from soil and plants as it decomposes. If you want to use sawdust, it is best to let it decompose first before applying it as mulch.

Inorganic mulches include gravel, crushed rocks, and pebbles. Inorganic mulches will not decompose meaning they do not require annual replacement. They can cause problems in that they are more difficult to deal with when applying to the landscape or when trying to go back in to replant plants. Unlike organic mulches, inorganic mulches do not help improve the soil in anyway. Do not use black plastic as mulch because it does not allow air, water, and nutrients to move into the soil.

Landscape fabrics get mixed reviews. Landscape fabrics can be applied before mulch to help reduce weeds. Landscape fabrics should allow air, water, and nutrient movement into the soil. However, there are some thoughts that landscape fabric does not allow enough water and nutrient movement into the soil. The material can be applied on bare soil before or after planting. Fasten the material to the soil and cut the material to fit around plants. If using landscape fabric, be aware that plants roots could begin to grow above the fabric. This can create problems by causing roots to dry out quickly and not get enough water or nutrients, leading to the plant declining. The fabric can be covered with organic mulch to improve the appearance and provide more of a barrier for weed growth. In place of landscape fabrics, many gardeners instead apply a layer of newspaper before mulch to help reduce weeds. The newspaper slowly breaks down into the soil, but if too think can create a layer that is hard for plant roots to break through.

When used properly, mulches can have several advantages in the landscape. By controlling weeds and conserving soil moisture, mulching can save the gardener time and energy along with making the landscape look better.

 Learn More!

Jessica Strickland is an Agriculture Extension Agent, specializing in horticulture for North Carolina Cooperative Extension in Wayne County. Horticulture program information can be found at Forward any questions you would like answered from this week’s column to

 Upcoming Wayne County Extension Gardening Programs

  • Grow to Can-Gardening & Food Preservation School. This school offers hands-on workshops that will teach you the basics on how to create your own garden and safely preserve the items you grow. School will be on Thursdays, April 7th thru May 12th, 4:30 to 7:30 p.m. The cost for the entire school is $50 per participant. This is a series of classes in which you can sign up for one or all of them. For more information on the school schedule, fees and to register contact the Wayne County Extension Office at 919-731-1520.
  • Save the date for the annual Spring Garden Festival & Plant Sale! This year’s event will be held on Saturday, April 23rd at the Wayne County Extension Office (208 W. Chestnut Street, Goldsboro). The Wayne County Extension Master Gardener Volunteers have a great event planned with gardening demonstrations, kids activities, along with a great plants for sale. Volunteers will also be on hand to answer your gardening questions along with having publications and soil test kits available. Doors will open at 9 a.m. and stay open until noon.