by Charlene Burgi
There is a change in the air. The afternoon thermometer still registers in the 80s, but evening temperatures are rapidly dropping. The cooler evenings find me and Jack spending more time outside assessing what is needed in the garden before winter hits. And we pray it comes with abundant rain and snow here in Lassen County, just as that wish extends for ample water supplies for the entire West Coast.
Our evening assessments determined our first priority is to add more mulch to protect the plants’ root systems this winter. Refreshing organic mulch should be done every other year, if not annually. During the summer months, organic mulch seems to break down more rapidly than during the winter months. But that’s not a bad thing: The decomposed mulch adds nutrients to the soil that, in turn, further break down to feed the plants. Additionally, the cool blanket of mulch in the summer miraculously becomes a warm comforter to those same roots in the cold weather.
We often use a metal probe to determine where more mulch is needed. We find the sunny gardens require more than the shade garden where the elements are not as harsh. In addition, with the pups using the sunny gardens as a personal playground, the mulch in those areas has a tendency to wander off. The differing depths of mulch needed in various areas can throw off our calculations. How do you figure out how much is needed?
Determining the quantity of mulch required for adequate coverage can be more specific than a wild guess about how many premeasured bags of bark to buy. A tape measure, paper, and a pencil are the only tools needed to come up with the cubic yardage. Once you know how many cubic yards are needed, you can purchase in bulk from the landscape materials yard, which may be more favorable to the pocketbook. Are you ready for this exercise?
- Measure the length and width of the planting area you need to mulch.
- Multiply those two numbers together to find the square footage of the area.
- Divide the square footage by 9 to convert to square yards (there are 9 square feet in a square yard).
- Determine the depth of mulch needed.
- Divide that number of inches needed into 36 (a yard equals 36 inches).
- Then divide that answer into the square yards to come up with the cubic yards of mulch needed.
Did I lose you? Here is an example. I know my shade garden is 20 feet by 30 feet, which equals 600 square feet. When I divide that number by 9, it equals 66.67 square yards. I want a thick 4-inch layer of mulch in the shade garden, but the mulch is already 2 inches deep, so I only need an additional 2 inches of mulch. I divide the 2 inches I need into 36 inches to come up with the number 18. I then divide 18 into the square yardage and find I need 3.7 cubic yards of mulch for my shade garden area. If I didn’t have any bark in the shade garden, but still wanted 4 inches of mulch, I would use the same formula but divide the 36 inches by 4. The answer of 9 is then divided into the 66.67 square yards equaling 7.4 cubic yards.
There are other ways to calculate this. I am certain many of you will be willing to share your formula with others facing this quandary but wishing to do the right thing for their plants. As with gardening, we all have our own ways of achieving the bottom line. Most of us work out problems in the fashion we were taught. Jack taught this method to me many years ago and it stuck. Does anyone have another formula that is easier? For gardeners who feel math-challenged, MMWD’s cubic calculator is another option!
Now might be a good time to go for an evening walk in the garden. What do you find on your list of things to do? Are the pruning tools sharpened? Are spring-blooming bulbs needed to fill in an empty space while requiring little water? Or is it just a pleasant night to take in the beauty?