“You are what you eat” is an old saying, and it points the way to picking the right mulch for your landscape. It’s common sense that if you add several inches of anything to your gardens each year it will affect the soil quality over time. Some mulches are much better for your plants than others. For instance, most plants prefer “acid” soils, so pine bark is healthier for them than hardwood mulch, and much healthier than dyed wood chips.
Good mulches turn into soil eventually. Your plants won’t appreciate being smothered by non-compostable mulches like cypress or cedar. These products work fine for paths and play areas, but they are poison for gardens. Many mulches contain recycled pallets and other waste wood. These can be bait for termites, and actually rob your soil of nutrients as they decompose. The ideal mulch should improve your soil, actually becoming rich humus that can be tilled in to loosen compacted soils and clay.
We’ve tried many mulches in our gardens over the years, and settled on pine bark for many reasons. We usually use shredded pine bark on new plantings, and then switch to pine bark nuggets after a few years because it lasts longer and discourages weeds better. Another thing we like about pine bark nuggets is that even when they’re wet they “breathe” instead of packing down, and they dry out quickly which discourages fungus diseases.
Pine bark mulch has a low PH, which means it is good food for evergreens, blueberries, dogwoods and other acid-loving plants. Mulching your beds with pine bark year after year will build your soil very nicely. Finely shredded hardwood compost mulches like Black Gold are next best. Proper composting kills weed seeds and diseases, so you’re not importing problems into your landscape. Poor quality mulches are more likely to breed funguses and mushroom colonies.
All mulches are not equally effective at weed control. Fine-ground mulches are much like potting soils; wind-blown weed seeds or blown grass clippings will sprout and root easily. Course bark mulches or “nuggets” aren’t so friendly to weed seeds, and they last much longer before turning to soil so they make better weed barriers for a much longer period. That makes them ultimately cheaper, because you need less in future years.
The first step in shopping for mulch is figuring out how much you need. Figure out how many square feet of beds you have to cover by multiplying how many feet long times how many feet wide. For three inches thick of cover you’ll need one cubic foot of mulch for every four square feet of beds. One cubic foot for every six square feet will give you a two-inch thick mulch job. Most mulches come in 2 Cubic foot bags, although convenience stores and mass merchants are now stocking smaller bags so they can advertise a lower price per bag.
All mulches are not equally good for your garden, and some can be downright harmful. There’s no requirement for labeling to disclose what exactly is in the bag. You get what you pay for with mulch. Smart gardeners choose mulch very carefully, and don’t just buy the cheapest thing they can find.
Editor’s Note: Steve Boehme is the owner of GoodSeed Nursery & Landscape, located on Old State Route 32 three miles west of Peebles. More information is available online at www.goodseedfarm.com or call (937) 587-7021.