How Much Does a Cubic Yard of Mulch Weigh?

Difference in Weight

• Garden supply companies sell their bulk products by the cubic yard. This is 26 cubic feet and three cubic yards can easily fill the back of a standard sized pickup. Because of the wide differences between the types of mulch it make a difference as to what is in the cubic yard. An organic mulch weighs around 200 to 500 lbs., while a cubic yard of stone mulch can weight from 2,600 lbs to almost 3,000 lbs. Oak weighs more than pine for the same volume, so even within the same mulch as wood chips a cubic yard of oak chips will weigh more than pine chips.

Moisture

• Moisture also affects the weight of organic mulches. Wood chips that are fresh cut will weigh significantly more than wood chips that are dry. The water has evaporates from the dry chips and is not counted towards the weight. For this reason the material is sold by volume and not by weight. Otherwise one person would purchase a lessor amount for the same or greater cost.

Rock Density

• The density of the inorganic material also affects its weight. Lava rock is often used as mulch, as is river rock. Lava rock is lightweight and porous, which are two of its strong selling points. The porosity of it allows it to trap water which then feeds the soil over time. River rock, though, is a denser sandstone with little to no cavities. It will weigh much more than an equal volume of lava rock.

Transportation

• Transporting large amounts of heavy mulch with a consumer pickup can cause problems if the weigh is not taken into account. It's easy to overload the capacity of the vehicle and have it fail. Even a small area of 160 square feet can take 2 cubic feet of river stone if done properly. This is almost 6,000 lbs. of rock to be transported, which is far beyond consumer vehicle capabilities. Having the supply company deliver the mulch may cost more, but it will be done by the proper vehicles.