If you have ground bees nesting in your yard this season or there seem to be more ground bees than last year, you’re probably wondering why these little guys and gals like to nest in your backyard (and not somewhere else).
Well, here are the top 9 reasons why you have ground bees in your yard …
You don’t water enough
Ground bees build their nests in dry areas in March and April in the northern hemisphere. But ground bees don’t only build their nests in dry sand – they also nest in the dry soil of potted plants (just like ants do), turf, and flower beds.
If your entire yard, with the potted plants, is kept damp by rain or is watered often enough, the bees and their larvae cannot survive under the ground and will not nest there.
In fact, using enough water at the right time of year can get ground bees to move on to a new location, without using any harmful pesticides in your yard. Click here to find out how to water ground bees out safely.
Your soil stays dry and sandy beneath the surface
Ground bees need soil that stays relatively dry under the surface in order to dig a nest for themselves and for the nest to remain intact. This is why they choose yards with well-drained soil, which is usually deep, loamy, and on a slope.
But some soil, even when you water it, never lets water penetrate the surface, and the water simply pools above the ground until it evaporates.
Soil that does not let water below the surface is called “hydrophobic soil”. This soil is unhealthy soil that lacks nutrients, has had all the healthy bacteria and fungi die off, is not well aerated, and is probably quite old.
You can test if your soil is hydrophobic by watering a small area well, then taking a handheld spade (called a trowel) and digging it straight into the freshly watered ground. Bring up the soil you just dug into, and look to see if the soil is damp right through or not.
If you have hydrophobic soil, the surface soil will be wet but the rest of it will be bone dry underneath on the trowel.
The good news is that ground bees help to aerate and replenish hydrophobic soil with their underground nesting habits. The bees will be around for four to six weeks, then die off.
And once they’re done, you can try to fix your hydrophobic soil in three simple steps:
- Add a wetting agent such as this organic one from Amazon to increase the soil’s absorbency
- Add a fertilizer to the soil. Here are three great options from Amazon: compost, manure, worm tea
- Cover the area with mulch, such as straw or wood chips that you can order from Amazon, to stop the soil from drying out and to add nutrients over time
You have abandoned burrows from other animals in your yard
Some animals make tunnels and burrows underground to live in. These could be ground squirrels, skunks, rodents, rabbits, moles, or gophers, depending on where you live.
When these animals abandon their underground homes, ground bees might move in. One beneficial ground bee that likes taking over deserted burrows and living there in a group is the bumblebee.
However, yellow jackets (wasps) also like to occupy abandoned underground tunnels and are a rather aggressive pest, so make sure you know how to tell the difference between a yellow jacket and a ground bee.
To prevent ground bees and yellow jackets from moving into abandoned burrows, walk around your yard in early spring. Look for any openings, cracks or burrows in the ground, and pack them tight with sand.
You have bare patches in your yard
If you have bare patches in your lawn or flower beds, where nothing is growing on the ground, ground bees could choose that spot as a nesting area.
To stop the bees from moving in, plant grass or groundcover in bare patches, or cover the area with a thick mulch so they can’t access the soil easily.
Your yard is south-facing
In the northern hemisphere, ground bees build their nests most often in yards that face south or south-west. In the southern hemisphere, ground bees favor north-facing yards.
This is because these sides of the yard tend to get the most sunshine, which is what helps to keep the soil dry and the underground bee nest warm and cozy.
This isn’t a hard and fast rule, and you might find ground bees nesting in a sunny area that doesn’t face south or north.
You have plants that bloom in early spring
Ground bees are excellent and important pollinators across the world. Even though they don’t make honey (click here to find out why not), ground bees spend their days collecting nectar and pollen from flowers for food, and they fertilize many thousands of flowers in the process, especially those of berries and fruit trees.
If you have plants or trees that flower in early spring when ground bees become active, they will be attracted to your yard for food and perhaps to build their nests.
Ground bees fly only a couple hundred yards from their nests to find food, so if you see ground bees buzzing on your flowers then you know that their nests are likely to be nearby.
You had ground bees last year
Most ground bees live alone. A female builds a nest underground, where she lays her eggs before dying off within a few weeks.
The eggs soon hatch, and the larvae live on nectar and pollen that the female placed by the eggs.
The larvae hibernate and stay in the nest in the ground over winter. They leave the nest in spring, to find food and mate with other ground bees.
If the young bees leave the nest and the conditions in the area remain good for ground bee life, then young females will often build their nests in the same area (your yard) to lay their eggs and start the cycle again.
The young female ground bees are looking for:
- Dry, sandy soil
- A sunny spot
- Flowers that bloom in spring, within a couple hundred yards
- Male ground bees to mate with in the area
The young male ground bees are looking for:
- Blooming flowers within a couple hundred yards
- Female ground bees in the area to mate with
This is why you seem to have ground bees in the same area of your yard every year: The bees aren’t “coming back”. They are the offspring from last year’s bees, who are emerging from the ground and building more nests, often very close to each other.
The following video gives a great explanation of the ground bee life cycle and shows young ground bees active above ground:
You don’t have honey bees in the area
Honey bees and ground bees are different types of bees and do not fight with each other, but they do compete for food.
Honey bees hoard pollen and nectar from flowers, and they can fly many miles from their nest to find them. Once the bees have collected all the pollen and nectar close to their hive, they move further out to collect more and more, which they store in their hive as honey for the winter.
This hoarding instinct can prove to be too much competition for non-aggressive ground bees in the area, who can only fly a couple hundred yards from their nests to collect the pollen and nectar they need to survive.
If there are no active honey bees in your area, there won’t be much competition for pollen and nectar in your yard. So ground bees will often choose to live there and feed off the blooms quite peacefully, without much rivalry or the fear of starvation.
You don’t have enough natural predators in your yard
Natural predators are animals and insects that eat ground bees, and they keep the ground bee population under control in an area. If there are no such predators in your yard, ground bees can continue to reproduce without much threat of being eaten.
Some of the animals and insects that eat ground bees are:
- Birds, like scarlet and summer tanagers, purple martins, and bee-eaters
- Certain spiders
- Predatory wasps (click here to find out what wasps really eat)
- Robber flies
- Small mammals, like skunks
But it’s good to remember that ground bee populations are under threat and these gentle bees should never be killed if it can be helped. It’s best to let them do their thing for the few weeks they are above ground, and not to worry them.