When most people hear the word "bee," they picture a hive — a structured colony of honeybees or a papery bumblebee nest tucked under a shed. But roughly 70 percent of the 4,000 native bee species in North America nest not in hives, cavities, or structures, but directly in the ground. They dig tunnels into bare soil, provision them with pollen and nectar, lay their eggs, and seal the entrances. The next generation emerges the following spring, mates, and begins the cycle again. No queen, no workers, no hive — just a solitary female, a patch of bare earth, and the quiet engineering that has sustained these species for millions of years.
And gardeners are eliminating their habitat at an alarming rate. Thick mulch, dense ground covers, landscape fabric, pavement, and the relentless quest to cover every inch of soil with something "tidy" has removed ground-nesting sites from millions of acres of residential land. A garden can have the most exquisite pollinator plantings imaginable, but if every square foot of soil is buried under 3 inches of mulch, the very bees those flowers are meant to feed may have nowhere to reproduce.
Which Bees Nest in the Ground?
The diversity of ground-nesting bees is extraordinary. Several of the most important pollinator families in North America are primarily or entirely ground-nesting.
Mining Bees (Andrena)
With over 450 species in North America, mining bees are one of the largest bee genera on the continent. They are among the first bees active in spring — some species emerge in March — and are important pollinators of fruit trees, spring wildflowers, and early vegetables. Mining bees excavate small burrows in bare, often compacted soil, leaving characteristic mounds of excavated earth around their nest entrances. Each female provisions her own nest independently.
Sweat Bees (Halictidae)
Named for their occasional habit of landing on human skin to drink perspiration, sweat bees are small (often under a quarter inch), frequently metallic green or bronze, and remarkably abundant. The family includes both solitary and semi-social species that nest in bare ground. They are generalist foragers that visit a wide range of flowers and are important pollinators of many garden crops including tomatoes, peppers, and cucumbers.
Digger Bees (Anthophora)
Robust, fast-flying bees that resemble small bumblebees. They excavate deep burrows in compacted or clay soils, sometimes in vertical banks. Digger bees are important pollinators of tomatoes and other nightshade family plants because they perform buzz pollination — vibrating their flight muscles at the resonant frequency of the flower to release pollen. Honeybees cannot do this.
Cellophane Bees (Colletes)
These bees line their underground nest cells with a secretion that dries to a cellophane-like waterproof membrane — a remarkable adaptation that protects developing larvae from soil moisture and fungal infection. Cellophane bees often nest in dense aggregations, with hundreds or thousands of individual nests clustered in a patch of suitable soil. These aggregations can alarm homeowners who mistake them for dangerous colonies, but cellophane bees are docile and rarely sting.
Plasterer Bees (Hylaeus)
The smallest bees most gardeners will encounter, plasterer bees are often mistaken for tiny wasps due to their nearly hairless bodies and yellow facial markings. While some species nest in hollow stems, many nest in the ground. They carry pollen internally — in a crop rather than on body hairs — which makes them invisible as pollinators to casual observers despite their important role.
What Makes Ideal Ground-Nesting Habitat
Not all bare soil is equal. Ground-nesting bees have specific preferences that vary by species, but several characteristics are consistently important.
Soil Type and Drainage
Most ground-nesting bees prefer well-drained sandy loam or sandy soil that is easy to excavate and does not become waterlogged. However, several species — particularly digger bees and some mining bees — prefer compacted clay soil and will nest in hard-packed paths, clay banks, and even cracks in dry clay. The key requirement is that the soil does not remain saturated — waterlogged nests kill developing larvae.
Sun Exposure
South-facing or east-facing bare soil that receives direct sunlight for at least six hours daily is strongly preferred. Sun-warmed soil accelerates larval development and allows adult bees to warm their flight muscles quickly in the morning. Shaded, north-facing soil rarely supports ground-nesting aggregations.
Slope and Grade
Sloped or raised ground that sheds water readily is preferred over flat ground. South-facing banks, raised bed edges, and sloped garden borders are natural nesting sites. The slope improves drainage and increases solar heating — both advantages for nest success.
Minimal Disturbance
Ground-nesting bees need their nest sites left undisturbed for at least one full year — from the time eggs are laid until new adults emerge the following spring or summer. Tilling, heavy foot traffic, and soil disturbance during this period destroys nests. The ideal nesting area is a patch of ground that nobody walks on, tills, or digs between March and the following June.
How to Create Ground-Nesting Habitat in Your Garden
Designate Bare Soil Areas
Choose a sunny spot in your garden — at least 2 feet by 2 feet, larger if possible — and keep it completely free of mulch, ground cover, and vegetation. The south-facing edge of a garden bed, the base of a sunny fence, or a raised area near pollinator plantings are all excellent choices. Scrape away any existing mulch and expose the mineral soil beneath.
If your native soil is heavy clay, you can improve it for ground-nesting bees by mixing in coarse sand to a depth of 12 inches to improve drainage and digging ease. A ratio of roughly 50/50 existing soil to coarse sand creates excellent nesting substrate for most species. Do not use fine play sand — it compacts too tightly.
Create a Bee Nesting Mound
A purpose-built nesting mound is the most effective way to provide ground-nesting habitat. Mound a mix of sandy loam soil 12 to 18 inches high in a sunny location. Shape it with a slight south-facing slope for maximum sun exposure. Compact the surface lightly — bees need firm enough soil to excavate tunnels without collapse, but not so hard they cannot dig. Leave the mound unmulched, unplanted, and undisturbed.
Position the nesting mound within 50 feet of your pollinator flower beds so emerging bees have immediate access to food. Female ground-nesting bees typically forage within a few hundred yards of their nests, so proximity between nesting habitat and flowers is important.
Leave Existing Bare Patches
If you notice small volcano-shaped soil mounds in your lawn, garden, or pathway, stop and observe before disturbing them. These are almost certainly ground-nesting bee entrances. The bees are not dangerous — most ground-nesting species cannot sting, and those that can are extremely reluctant to do so. Leave these areas undisturbed for the season. If they appear in an inconvenient location, protect them with a small marker or low fence rather than destroying them.
Reduce Mulch Coverage
The modern gardening practice of mulching every exposed soil surface eliminates ground-nesting habitat across entire properties. While mulch has genuine benefits for moisture retention and weed suppression around plants, not every square foot of garden needs to be covered. Leave gaps between mulched areas where bare soil is exposed to the sun. Along garden bed edges, keep a 6-to-12-inch strip of unmulched soil as a potential nesting corridor.
Eliminate Landscape Fabric
Landscape fabric — the woven or non-woven geotextile placed under mulch to suppress weeds — is an impenetrable barrier for ground-nesting bees. It prevents females from accessing soil and prevents emerged adults from reaching the surface. If you currently use landscape fabric, consider removing it from areas where you want to encourage ground-nesting and replacing it with targeted mulching that leaves bare soil exposed in spots.
Protecting Ground-Nesting Sites from Common Threats
Irrigation
Overhead irrigation and sprinkler systems can flood ground nests and drown developing larvae. If you use irrigation, direct it away from bare soil nesting areas. Drip irrigation targeted at plant root zones is ideal for pollinator gardens because it keeps nesting soil dry while watering plants effectively.
Soil Amendments
Avoid applying fertilizers, lime, or soil amendments to designated nesting areas. Chemical inputs can alter soil chemistry in ways that are harmful to developing bee larvae. Nesting soil should remain as natural and undisturbed as possible.
Pets and Foot Traffic
Dogs running through nesting areas and frequent foot traffic compact soil excessively and crush shallow nests. If you identify an active nesting aggregation, redirect traffic around it. A few stepping stones placed away from the nesting zone can guide foot traffic without drawing attention to the bare soil area.
Well-Meaning Cleanup
The biggest threat to ground-nesting bees in residential gardens is the gardener's own desire for tidiness. Resist the urge to mulch, plant, or "improve" bare soil areas that bees are using. A patch of bare earth next to a flower bed is not an eyesore — it is a maternity ward. Frame it mentally as a feature, not a flaw, and educate anyone else who maintains your garden about its purpose.
Identifying Ground-Nesting Bee Activity
Ground-nesting bee nests are easy to spot once you know what to look for. Watch for these signs in spring and early summer:
- Small soil mounds: Pencil-eraser to nickel-sized mounds of excavated soil, often with a small hole in the center. These appear overnight as females dig new burrows.
- Low hovering: Female bees hovering a few inches above bare soil, appearing to search the ground for nest sites. Males may patrol the same area looking for mates.
- Soil entry and exit: Individual bees disappearing into the ground or emerging from small holes. Watch a suspected nest entrance for five to ten minutes on a warm, sunny morning — if a bee enters or exits, it is an active nest.
- Pollen loads: Female bees returning to the ground carrying visible pollen on their hind legs or belly — evidence that they are provisioning a nest with food for their larvae.
If you find active nesting, celebrate. It means your garden is providing not just food but complete reproductive habitat — the full cycle of pollinator support that most gardens fail to offer. Combine bare soil nesting areas with perennial plantings for a garden that sustains bees from birth through foraging and back again.
Frequently Asked Questions
Will ground-nesting bees sting my children or pets?
The overwhelming majority of ground-nesting bees are solitary species that are extremely docile. They lack the colony-defense instinct of honeybees and social wasps. Most solitary bees can technically sting, but they almost never do — stinging risks their own survival, and without a colony to protect, the evolutionary incentive is to flee rather than fight. Walking barefoot directly on a nest entrance might provoke a sting in rare cases, but the sting is typically milder than a honeybee sting. Ground-nesting bee aggregations coexist safely with pets and children in thousands of yards.
How do I tell the difference between ground-nesting bees and yellowjackets?
Yellowjackets (Vespula spp.) also nest in the ground and are far more aggressive than ground-nesting bees. Key differences: yellowjacket nests have a single, larger entrance hole (often 1 to 2 inches in diameter) with heavy traffic — dozens of wasps entering and exiting per minute. Ground-nesting bee aggregations have many small individual holes (pencil-eraser sized) with one bee per hole. Yellowjackets are distinctly yellow and black with a narrow "waist." Most ground-nesting bees are fuzzy, often brown or metallic, and smaller. If in doubt, observe from a safe distance — yellowjackets are noticeably aggressive when disturbed, while ground-nesting bees are not.
Can I have ground-nesting bees and mulch in the same garden?
Yes — you do not need to eliminate mulch entirely. The approach is selective: mulch around plants where moisture retention and weed suppression are needed, but leave intentional bare patches in sunny areas for nesting. A garden can have both mulched beds and bare-soil nesting zones. The key is ensuring that at least some sunny, well-drained soil remains exposed and undisturbed.
How many ground-nesting bees will use a nesting area?
It depends on the species. Some ground-nesting bees are solitary in the strictest sense — a single female per nest with no aggregation tendency. Others, like cellophane bees and certain mining bees, form dense aggregations of hundreds or thousands of individual nests in a small area. A well-positioned nesting mound in a garden with good floral resources might attract a few dozen to a few hundred nesting females over several years as word spreads (bees do return to natal sites and recruit others through pheromone signals). Even a single nesting female represents successful habitat provision.