Mulch is a layer of material spread over the surface of soil to help regulate temperature, retain moisture, and suppress weed growth. Applying the correct type and quantity is a foundational step in any landscaping or gardening project. This article provides a structured approach to purchasing the right amount and type of material efficiently, ensuring you maximize the benefits of your investment. The process involves understanding material properties, accurately measuring the application area, and selecting the most practical purchase format.
Selecting the Right Material
The first step in any successful mulching project is determining whether an organic or inorganic material is appropriate for your specific needs. Organic mulches are derived from once-living sources and break down over time, which means they must be replenished periodically. This decomposition process adds valuable organic matter and nutrients back into the soil, improving its structure and fertility. Shredded bark and wood chips are highly popular choices for landscape beds because they interlock well, making them resistant to wind and wash-out.
Other organic options include pine needles, which are suitable for acid-loving plants like azaleas and blueberries because they maintain a lower soil pH as they decompose. Straw is often chosen for vegetable gardens as it is light, easy to spread, and helps to keep developing fruits and vegetables clean.
Conversely, inorganic mulches like stone, gravel, or rubber are permanent and do not enrich the soil. These materials are best used in non-planting areas or for decorative purposes where a long-lasting, low-maintenance solution is desired. Stone and gravel offer excellent drainage but can absorb and radiate heat, which may stress certain plant roots in full sun. Rubber mulch is highly durable but has been shown to be more flammable than organic alternatives. Selecting the right material is a functional decision based on the location and the desired long-term outcome for the underlying soil.
Calculating Your Coverage Needs
Before purchasing any material, you must accurately determine the volume required to cover your designated area at the proper depth. Begin by measuring the length and width of the area you intend to mulch, expressing all measurements in feet to calculate the square footage. For irregularly shaped beds, it is helpful to divide the space into smaller, more manageable sections and calculate the area of each separately before summing the totals.
Next, decide on the appropriate depth for the application, which is typically between two and three inches for most general landscape beds. Applying a layer thinner than two inches may not provide sufficient weed suppression or moisture retention, while a depth exceeding four inches can restrict air and water flow to the plant roots. The final calculation requires converting your depth measurement from inches into feet by dividing it by 12. You then multiply the total square footage by this converted depth to find the volume in cubic feet.
Since mulch is almost universally sold by volume, the final step involves converting the required cubic feet into cubic yards, which is the standard unit for bulk purchases. You must divide your total cubic feet by 27, as there are 27 cubic feet in one cubic yard. This final figure represents the precise volume you need to purchase, helping you avoid the costly mistake of over-ordering.
Choosing Between Bagged and Bulk Mulch
Once the required volume is calculated, the final consideration is the purchase format: bags or bulk delivery. Bagged mulch is highly convenient for smaller projects, touch-ups, or areas with difficult access, as it is pre-packaged, usually in two-cubic-foot quantities. This format is easily transportable and allows for simple storage and handling. However, the cost per volume for bagged material is significantly higher, often requiring over a dozen bags to equal one cubic yard.
Bulk mulch, delivered loose by a truck and sold by the cubic yard, is the more economical choice for large-scale landscaping projects. Purchasing in bulk offers a substantial cost saving per unit of volume compared to packaged bags. This format also reduces environmental impact by eliminating plastic bag waste. While bulk requires a designated drop-off area and more manual labor for spreading, it is the most practical solution when several cubic yards of material are needed.