Attracting Beneficial Bees
DK - Gardening Step by Step , 2011 Dorling Kindersley Limited
Pollinating insects play a critical role in maintaining natural plant communities and ensuring production of seeds in most flowering plants. The main insect pollinators are bees, because most of their life is spent collecting pollen.
It is an irrefutable fact that bees are some of the most important pollinators in our ecosystems, but in recent years there has been a steady decline in bee populations around the world. Loss of habitat, overuse of pesticides, herbicides and fungicides and an increase in the sale of hybrid flowering plants that offer little, if any, food for bees are all part of the problem. How can we help reverse this trend? Kim Eierman, environmental horticulturist and founder of EcoBeneficial!, a horticulture communications and consulting company, offers some advice on how to attract bees to your yard and garden as well as some bee facts you might not know.
Honey bees are at the top of the list in terms of being threatened, but they are not the only bees that are crucial in pollination. "In the United States we have about 4,000 species of native bees which vary dramatically in their appearance, lifestyle and forage needs," Eierman says. "One of the secrets that most homeowners and gardeners don't know is that we have different bees coming at different times of year into our gardens. Some emerge early in the season and some much later. Some are a little tougher than others in being able to tolerate rainy weather and less than warm conditions. Others are reliant on very sunny and dry conditions."
For example, those tiny creatures which are classified as hoverflies and are more commonly referred to as sweat bees, play an important part in the ecosystem. You might see them levitating over tiny plants that offer good nectar or gathering pollen from small flowers. Other great but lesser known pollinators include bumble bees, mason bees and even carpenter bees, which like to nest in woody areas and are sometimes considered a nuisance because of their tendency to burrow in structural timbers.
Bumble bees, in particular, are a more efficient pollinator of blueberry plants than honey bees because of an unusual characteristic. "Bumble bees exhibit something called buzz pollination," Eierman explains. "They're actually able to push themselves up into the blueberry flowers and vibrate their bodies, collect pollen and go on to the next plant which, honey bees cannot do."
To order to attract all types of bees, it is important to create a garden plot or space in your yard that meets all of the following criteria. Not only will your garden attract bees but also other important pollinators like hummingbirds, butterflies, beetles, wasps, moths and bats.
Diversity in the Garden
This is a crucial requirement in creating a bee-friendly environment. You want to make sure you have plants that are blooming from early spring through the late fall. "We call that succession of bloom," Eierman states, "and that means having a variety of plants in bloom at each given season because different bees are attracted to, and able to utilize, different plants." Even if you are only focused on having an edible garden, you should still try to include a combination of flowering native perennials, woody plants and shrubs with your herbs and vegetables. Eierman adds, "I would always recommend at least three plants of different species in bloom in any given season, and, if you have room for more, even better."
Another recommendation is to "leave just a little bit of your landscape with bare soil in full sun, if possible." This is because most native bees are ground nesters. "Some native bees utilize old mouse burrows or something that's been left from another creature. We've been told that we have to cover everything with mulch…but leave a little bit of room for those ground nesting bees."
Emphasis on Native Plants
"A lot of our native bees are specialists and have evolved with very particular plants without which they cannot survive," cautions Eierman. "As we start to become more global in our plantings, we're losing a lot of those native species and, accordingly, losing a lot of native bees." In fact, numerous native trees and plants are early bloomers and offer an important source of pollen for the first bees of the season. As an example, Eierman mentions that in her home state of New York, "maples come into flower in the early spring and are a very important source of early nectar and pollen for early, emerging bees, including honey bees." Eierman recommends a number of native perennials for your pollinator garden on her website. If you are not certain about which plants are native to your region, you should contact your local native plant society.
There are all sorts of factors that bees use to locate plants. "It may be the plant size, the flower size, shape, fragrance and the color," Eierman explains. "Interestingly, bees do not see color the same way that we do. They see a UV spectrum, so they don't actually see red unless there is UV in that pigment...Generally bees are going to be attracted to flowers that are blue, purple, yellow and white."
One of the main reasons to avoid planting hybrid plants and flowers, despite their aesthetic appeal, is that they may offer very little in the way of pollen or nectar for bees. In fact, the proliferation of hybrid plants in gardens is one reason bee populations are declining. An example of a popular recent hybrid is double-flowered coneflower (Echinacea). Various hybrids of this plant are often sterile, offering no nectar or pollen to bees and no seeds for birds, either. A much better choice would be Echinacea purpurea in its natural form as it grows in the wild. This purple coneflower with its pink petals is not only strikingly beautiful but serves up nectar and pollen to bees and provides seeds for birds.
Create a Pesticide Free Zone
The use of synthetic pesticides, herbicides and fungicides is killing our bees, not to mention other species such as amphibians and beneficial insects. "Even if we're using organic pesticides," Eierman warns, "they may be extremely lethal to bees, too. Bees are very sensitive to pesticides." Often gardeners may mistake a positive sign in their landscape as a negative. Some minor leaf damage on a plant might not be a sign of disease, pest invasion or poor health. Instead, it could signal the presence of bees—such as a leafcutter bee, which removes circular pieces of leaves from plants to line its nest. This has little to no effect on the plant's health, but you might interpret it as a problem to treat with pesticide and if you do, the impact will be negative, not positive.
Cut Back Perennials in Early Spring
To provide a habitat for pollinators, and a food source for birds over the winter, you should always cut back your perennials in the early spring before they start to grow back and not the late fall. There are several reasons for this. Many beneficial insects overwinter in hollow plant stems and may utilize standing plant stems, such as the praying mantis. Perennials may also provide lots of seeds for overwintering birds including neo-tropical migrating birds that return in early spring. One rule of thumb for cutting back your perennials in early spring is to make sure the ground is fairly dry. "If we go into the garden and start cutting back and the ground is really, really wet, we're compacting soil, which is the enemy of healthy soil biology," Eierman states.
Other Bee Attraction Tips
Not everyone has a large garden space or yard, but you can still create a bee-friendly environment on a patio or balcony large enough to accompany a small but diverse green space. "When I think of small spaces and best selections to make, I think about multiple-duty native plants—plants that do more than one thing ecologically," Eierman notes. "Agastache foeniculum (anise hyssop) is an example of a plant I really love for its ecological value, plus it's very beautiful. It's a spiky, purple-flowered plant that was commonly used medicinally by Native Americans and colonists. It has a very long bloom time and it has lots of nectar, lots of pollen. Additionally, it provides seeds for birds."
A small water feature is also beneficial for bee-friendly gardens. Like every other living creature, bees need water but access can be a problem. Bird baths are often too deep (bees can easily drown in them) and too dangerous (birds are predators). A small pond or stream with gently sloping entry points to the water is ideal. If you don't have a water feature, you can "take a little saucer and fill it with pebbles, and put some water in there so there's enough for the bees (and butterflies) to access."
For more information on how to attract bees to your yard and help sustain a healthy ecosystem, visit Kim Eierman's website, EcoBeneficial!.