How to Apply Mulch

Mulching your garden beds twice a year – once in early spring and again in a late fall – helps your garden retain moisture within the soil. It also prevents the triggers that cause the seed from various weeds to germinate. To calculate the amount of mulch needed, estimate the square footage of the garden bed by multiplying its length by its height. Multiply this number by 4 inches (the target-height of the applied mulch) to find the cubic feet of mulch needed. However, bulk mulch is sold in yards. To convert cubic feet to yards, divide that number by 27 (there are 27 cubic feet in a yard). You can also use this mulch calculator.

A diagram showing how to apply mulch to the base of trees and shrubs. — too much mulch causes rot

Bagged Vs. Bulk

Bagged mulch is easier to stack and store. It’s also a time-saver, because bagged mulch requires little to no clean-up, a wheelbarrow is not required, and it is easier to transport and spread. Unfortunately, having bagged mulch delivered can cost approximately 15% more than bulk mulch. The price of the bagged mulch itself is typically about 40% more expensive than mulch bought in bulk.

Spreading the Mulch

You’ll want to end up with 2-4″ of mulch across the garden beds. If you mulch regularly and already have a few inches of mulch built up, just top it off with an additional 1″. Alternatively, you can remove all of the mulch and start over from scratch. Never pile mulch on the trunks of trees or shrubs. Too much mulch facilitates rot and fungal issues. It also prevents water from reaching plants’ roots. To further prevent weed-growth, you may want to apply a pre-emergent herbicide or lay down newspaper or landscaping paper prior to applying mulch. To achieve a neat, finished look, smooth the mulch out by hand after it is applied to the garden bed. Alternatively, a pitchfork or steel rake can be used to smooth out the mulch. A pitchfork will also come in handy if working with bulk-mulch, as it easily lifts mulch out of the wheelbarrow. Never leave mulch on lower branches/leaves as this looks sloppy.