Many of the benefits of soil are easy to appreciate. It grows the plants we love to admire and consume and makes up most of the ground we walk on.
Studies have even shown that working in soil bare handed can improve the mood of the gardener through the release of serotonin by specific soil dwelling microbes. We’ve also learned from the big screen that in the right conditions soil can disguise the wearer from man-hunting extraterrestrials, and in the event of a waterlogged planet could one day perhaps be used as currency.
Despite these and other benefits, a pile of dirt does not come across as a good place to live for most humans. This distinction separates us from most other animals that live on land. In fact, the majority of land lubbers spend at least part of their lives burrowing, eating, or hiding amongst roots and rocks underground. From microscopic organisms that tirelessly work to transform atmospheric elements like nitrogen into usable forms, to large and voracious moles that turn your lawn into a subterranean superhighway, it’s reasonable to say that dirt is often the most overlooked real estate when it comes to gardening for wildlife.
This is especially true for bees, the majority of which turn to the soil in order to raise their young for future generations.
About 70 percent of the 4,000-ish bee species native to North America use the ground to make their nests. If you’re a regular reader of this column, you are probably already aware that the vast majority of these diggers are called solitary, which means that a single female does all of the work in building and provisioning rooms for her young. Ground nesting bees generally excavate tunnels on their own, with each species making a different size and style of domicile.
Some commonly seen ground nesting bees are cellophane bees, which use specially formulated chemicals to line their tunnels and keep moisture, diseases, and other hazards away from their young. Also easily observed are long-horned bees, which sport antennae of impressive sizes and are especially drawn to sunflowers.
There are a wide variety of bees under the umbrella of “digging bee,” many of which are around the size of a honeybee but sport a slightly darker complexion. The brilliant green, blue and gold sweat bees also live in the soil, typically around dense colonies of ferns or other groundcover. Although most diligent gardeners have been trained that a patch of bare soil is anathema to logical gardening techniques, leaving even a few areas of sparse mulch can give these bees access to the soil. Avoid using landscape fabric, as it tends to drive these pollinators away from your beds. Most solitary bee nests are around 6 inches in depth, so it is also important to avoid tilling whenever possible. If it must be done, keep your tines as shallow as possible.
A properly functioning ecosystem, to use a well-worn cliche, is a lot like a new car traveling at high speeds. Both are clearly powerful, yet at the same time display a grace that makes it look easy. Eliminating even a single plant or animal from an ecosystem is akin to removing a screw from said hurtling car. The loss of a screw might not have an immediate impact on the car, however remove enough and eventually it will come to a violent stop. The same holds true for the landscapes around us. Even the most unsavory organism plays a vital role in the ancient ecosystem-machine. Paying attention to the condition of the soil in and around your area, and making sure local wildlife has access to your dirt are both major steps in preserving and restoring nature’s Cadillacs.
Brannen Basham is a writer and horticulturalist. Together with his wife, Jill Jacobs, he owns Spriggly’s Beescaping, focused on nature education and habitat restoration. He recently published his first book, “A Guide to the Wonderful World Around Us: Notes on Nature.” For more information visit www.sprigglys.com.