Parks Department

To Mulch or Not to Mulch

Now is the time of year that homeowners start to think about ordering mulch for their landscapes. There are many types of mulch to choose from including hardwood mulches, pallet mulches, straw, pine needles and peat moss and stone. You just need to decide which mulch is best for your needs.

Mulch is supposed to retain moisture, keep the weeds down and provide an organic cover that will break down eventually providing nutrients to the landscape. It protects the roots from the summer heat and the drying winds of the winter.

If you are mulching your home's landscape, usually hardwood mulch is best. You can buy it single, double or triple shredded in bulk form. It has a dark color to it and accents your plantings.

Pallet mulches are just that, shredded pallets that have been dyed various colors. I don't recommend since many pallets are treated with insecticides in warehouses. They are also made with softwoods that break down quickly. The colors are also fake looking. Mulch is not supposed to match your house color or to stand out in the landscape. It is supposed to suppress weeds and retain moisture.

Bagged mulch is an alternative for bulk mulch if you only need a small amount or have limited access for delivery of bulk mulch.

Straw is a good choice for mulching vegetable gardens. It suppresses weeds and breaks down over the winter, allowing you to till it into the soil the following spring and add organic matter.

Pine needles are a good mulch for acid lovers such as azaleas and rhododendrons. They aren't very neat and best used in an informal setting.

Many people use peat moss as mulch. It really isn't recommended for a number of reasons. One reason is that it is virtually impossible to keep it from blowing away while you spread it out. It has to be kept moist all the time. If it dries out, it forms a hard crust, which won't allow rain to penetrate it. While it is good to incorporate peat moss into the soil when needed, it does acidify the soil, changing the ph balance. When the soil is too acid, many nutrients become unavailable to the plants. Therefore it is best to used peat moss as a soil amendment when needed.

River rocks, beach stone and lava rocks are touted as permanent mulches. They are heavy, expensive and one of the worst things you can use as a mulch. Rocks absorb heat and can reflect heat onto plantsa terrible idea in the midst of a heat wave. It's also not a good idea in the middle of winter either since it tricks the plant into thinking it is warmer on a sunny day. The plant may even start to put out buds, which can be killed on a cold evening.

When dirt and leaves get into the rock beds, you must keep them clean otherwise you will be weeding the rocks. If you really love rocksget a big one and use it as a focal point.

Plastic is not a mulchperiod. It is one of the quicker ways to turn your soil into muck, prevent water from reaching the plants and generally making your property look like a dumpsite. Enough said.

A warning about those free wood chips that tree companies offer to you if they are in the neighborhood. These chips are fresh meaning that they will begin to heat up as they break down. DO NOT put them around your plants! These are best left to cool down in a pile at the corner of the yard for at least 6 months. If you want to use them as a pathway, you can do that but not as a landscape mulch. That's because as the chips break down they draw nitrogen away from the plants, giving them a chlorotic (yellowish) appearance. This can actually kill your plants. Many times trees are cut down down because of disease or insects. Sometimes there are vines in those trees including poison ivy. You don't want to spread someone elses problems into your landscape and you certainly don't want poison ivy. Just remember "there ain't no such thing as a free lunch! (mulch)"

When putting mulch around trees and shrubs, make sure that you don't put it right up against the trunk but rather an inch or two away from it. That prevents little creatures from making a home too close to the trunk and damaging the trunk by gnawing on it. You also don't want to put too much mulch on the beds either. On a new bed, 2-3 inches is sufficient. Adding another inch or two every year is a good idea to replenish the mulch. You should never have more than 3 inches on a bed because you can smother the plant roots by preventing their intake of oxygen. A little mulch is a good thing, a lot is not.


3 cubic feet of bagged mulch will cover: 36 square feet to a depth of 1 inch
18 square feet to a depth of 2 inches
9 square feet to a depth of 4 inches


1 cubic yard will cover: 162 square feet to a depth of 2 inches
81 square feet to a depth of 4 inches

To determine how many cubic feet of mulch is needed, you need to calculate the surface area and the desired depth coverage. There are 27 cubic feet in a cubic yard. One cubic yard will cover a 324-square-foot area with an inch of mulch. Figure out the square footage of your bed, that is the width times the length for square or rectangular shaped beds. The square footage of a circular bed is the distance from the middle of the circle to the outside, multiplied by itself and then multiplied by 3.14 (which is pi).

Multiply your square footage by the depth desired (in inches) and divide by 324 square feet. This will tell you how many cubic yards you will need.

1 acre = 4840 square yards
1 bushel = 32 quarts
1 cord = 128 cubic feet
1 cubic centimeter = 0.061 cubic inch
1 cubic foot = 7.481 gallons = 1728 cubic inches
1 cubic inch = 0.554 fluid ounce
1 cubic meter = 1.308 cubic yards
1 cubic yard = 0.765 cubic inches = 27 cubic feet
1 ton = 2000 pounds
1 yard = 0.9144 = 3 feet = 36 inches
1 square yard = 9 square feet
1 cubic yard = 27 cubic feet