For farmers and homesteaders, it just makes sense to promote the myriad of busy buzzing insects about your farm. By promoting native bees you’re effectively promoting the overall health of the ecosystem that you are responsible for as a farmer–since bees are a keystone species and their health and well-being directly impacts plants and animals all the way up the food chain. A healthy ecosystem is going to result in improved yields–whether you’re farming for vegetables, or farming grass for your cattle herd–the health of your farm’s ecosystem can directly impact your harvest–and so too your profitability. See this post for more details about the benefits of supporting native pollinators on your farm, and this one for information about who exactly the pollinators are–but for the purposes of this article we will be talking largely about native bees, of which there are some 4000 species in North America, and more than 20,000 world-wide. Once you’ve committed yourself to the concept of promoting your local native bee populations, there are a number of ways you can improve and create habitat, safe-guard their existence, and encourage their proliferation.
Step 1 – Recognize existing native bee habitat
First evaluate your farm for existing nesting habitat. Often we have colonies of native bees present that we are simply overlooking. Take a walk around your farm to look for these areas. Sites for ground-nesting bees
Remember that 70% of native bees are ground-nesters. Look for spots where the soil is of poor quality, bare or sparsely vegetated. Look for the entrances of ground-nesting native bees–often they will be marked by a small mound of soil that has been excavated, but it may also be little more than a small hole in the ground. Usually they will be located in marginal area of the farm, like the banks of drainage ditches, or close to buildings or other structures. Sites for wood and cavity-nesting bees These bees typically do not excavate their own nests–instead they take advantage of the tunnels created by burrowing beetle larvae in dead wood. Or they may utilize the center of pithy-stemmed shrubs, even brush piles, while bumble bees frequently nest in old rodent burrows or under tussocks of grass. Look for dead wood, brush piles, dense shrubby snags, and overgrown native bunch grasses. Finding important plants
Once you’ve noticed that native bees are indeed present, learn to recognize the plants supporting them. The best of these will be crawling with many insects–mostly bees–and may be found in area along the roadside, in field boarders, around farm buildings, and under utility easements. These flowers are not a distraction from your crops–but actually help local bees to reproduce with greater success. Try to discern how much forage is available for the native bees. A study performed by researchers at the University of California, show that when approximately 30% of the land within three-quarters of a mile of the crop-fields is growing natural habitat, native bees can provide all the pollination necessary for a crop of watermelon. And in Canada–Lora Morandin from the University of California–discovered that in the absence of honeybees, canola farmers can maximize their income if 30% of the farmland is left in it’s natural habitat–thanks to pollination by wild bees. Look at the flowers, shrubs, and even the trees growing on and around your farm. Are they mostly native species? Do you have a mix of native and naturalized (non-invasive) species, or do you have invasive flowering weeds present on the property? How far away from the farm and your crop-fields are these areas located? The typical foraging distance of native bees is about 500-feet to half a mile from their nest, with the larger species flying farther than the small ones. Large area of pollinator habitat should be within half a mile of an insect-pollinated crop in order to be of the greatest benefit for crop production.
Take note of the point in the season when they flower–which plants flower in the spring, which in the summer, and which ones flower in the fall? How many are flowering during each season? Native bees need forage available throughout the duration of the growing season in order to reproduce and survive. And finally–what are the landscape features of your farm? How many acres is the average size of your crop field? What additional landscape features are located within a mile of the crop field? For example–do you have existing vegetative buffers, to catch drifting insecticides (if you use them), hedgerows, windbreaks, fence-rows of diverse tree and shrub species. Do you maintain flowering cover crops or a bee-pasture, or do you allow any crops to bolt and flower, which also offers forage for native pollinators. Do you have a water source for native bees on the farm? Once you’ve found these nesting and foraging sites, leave them alone–preserve them–make the commitment to keep those sites in tact in order to maintain the existing populations of native bees.
Step 2 – Adapt your farming practices
Farmers can help conserve local populations of native bees by making adjustments to their management practices. Even minor changes can make a big difference. Are you using insecticides? Ultimately, one of the best things a farmer can do is to avoid the use of pesticides. Most pesticides kill native bees directly–on contact, while others kill bees indirectly–the pesticide may be carried inadvertently back to the hive in the pollen and nectar, and fed to other bees. Even some fungicides can kill bees directly–or they may have a sub-lethal effect on the bees–reducing the numbers of offspring the female bee can produce for the next season. When insecticides can’t be avoided–employing an IPM program (Integrated Pest Management) is a good measure for controlling pests and protecting native bees at the same time. And should the need to apply an insecticide or fungicide arise–spraying at night, when pollinators are inactive, spraying only outside of bloom periods, and carefully considering the drift path of insecticides–are important methods for protecting existing populations of native bees. Tillage and weed control
Extensive tillage destroys the nests of shallow ground-nesting bees, and hinders the emergence of bees nesting deeper in the ground. Farmers should look for nest sites that already exist before tilling. Some native bees are very tightly connected with their host flowers–such as squash bees with cucurbit crops. The females may dig vertical tunnels in the ground directly next to the plant, and the next generation of bees are typically concentrated 6-12 inches below the surface of the ground. Plowing destroys these nests, and kills most of the developing bees. Farmers who discover squash bees living in their fields of melons and squash should try setting their plows at shallower depths–less than 6 inches–or look into no-till practices. Land management techniques Are you grazing, burning, mowing, or haying on and around your farm? Each of these methods have positive and negative impacts on your local native bee populations. Consider all aspects carefully before moving ahead with maintenance of the landscape. Grazing – While common practice–can alter the structure, diversity, and growth of the vegetation within a habitat, which can impact the local insect community. When flowers are scarce, grazing can result in insufficient forage for pollinators. Grazing also poses the threat of destroying potential and existing nest sites, and can result in the direct trampling of adult bees. Burning – Fire management of the landscape can have a highly variable effect on insect communities. When used appropriately, fire can restore and maintain habitat for pollinators; but if used too frequently it can result in a dramatic decrease of invertebrate populations.
Mowing – Like grazing, mowing can suppress the growth of woody vegetation–thus maintaining vegetative pastures where pollinators thrive. However–it can also negatively impact insects through direct mortality–especially of the egg and larval stages when nests are mowed under, because those bees cannot escape. Mowing also creates a uniform field–destroying features like the grass tussocks that bumble bees prefer to nest under. What’s more–mowing very abruptly removes almost all flowers. The landscape can still be managed though–to maintain those open areas–if farmers conduct mowing and burning when plants and pollinators are dormant (in the late fall and throughout the winter months–depending on where you are located). Limit the disturbance to one-third or one-fourth of the landscape, to ensure the survival of some of the native bee populations, so that they may recolonize the managed area. And practice rotational grazing–using a carefully planned to suit the conditions of the site. Practice bee-friendly farm management There are a number of ways farmers can adjust their management practices to encourage pollinator populations on and around their farms. Even the most minor changes can make the world of difference to your native bees.
- Diversity of crops – Growing a wide variety of crops can support native bees by extending the bloom period.
- Staggered plantings – If you specialize in a single crop, consider succession plantings to encourage pollinator populations. For example–growing early and late-flowering blueberries or apples allows more foraging time by the native bees–increasing their reproductive success.
- Allow some crops to bolt – Leaving a portion of your crop in the ground, and allowing them to mature and flower before you plow them under is a simple delay in management that provides an additional source of food for your bees.
- Strategic crop rotation – When rotating crops, moving it to a new field 500-1000 feet away allows the offspring of the bees that are currently foraging on that crops flowers to find the new site the following year.
- Non-chemical alternatives to pesticides – Maintain a healthy and diverse landscape to deter pests and diseases. Practice biological controls, such as hand-picking or crushing larger insects, or spraying with soapy water. Employ good sanitation practices–remove infected leaves and the previous year’s crop from the area to further limit the spread of disease. For larger farms where hand-picking is not practical–utilizing IPM methods can be a good compromise.
- Tolerate weeds – While weed management is important for successful crop production–some weeds are important food sources for bees and other beneficial insects. Tolerating the presence of weeds on the farm can go a long way toward providing additional food for crop-pollinating insects.
Step 3 – Provide additional habitat
If you’re looking to actively increase the populations of resident bees on your farm–you can increase the available foraging habitat to include a range of plants that bloom throughout the spring, summer, and fall–providing an abundant supply of pollen and nectar all season long.
Cover crops & bee-pastures: Growing appropriate cover crops and letting them bloom, or devoting some areas to specialized bee-pastures are 2 easy ways to include your native bees. Bee-pastures are fields growing plants that offer superior food for bees. They offer an abundant bloom throughout the nesting period and especially during the larval stages, and bee-emergence. Usually these pasture consist of high-density wildflower meadows with a diversity of plant species, including many native plant varieties, but possibly some non-native species which are not aggressive or invasive. Understory plantings: You can also use cover crops as understory plantings in orchards, where the flowers bloom all at once, and then are gone, leaving little else for the rest of the year. Smaller plantings throughout the farm: Placing smaller plantings of wildflowers every 500-feet throughout the farm helps native bees move deeper into the farm. These potential nesting sites mean the bees won’t have to go far from where they are foraging on a crop to find new food sources coming into bloom once your crop has flowered.
Promoting the health of your farm’s ecosystem by focusing conservation efforts on native bees is a great way to increase the viability of your farm. There are programs available for farmers interested in pollinator conservation–contact your local Natural Resources Conservation Service to find out more about the resources they’re offering farmers to do just that. And keep in mind that some of the best measures you can take actually reduce your expenses–or cost nothing whatsoever–so what are you waiting for? Start today! What do you think? Is it worth it to go the extra mile to promote the health of your farm’s ecosystem? Feel free to share your thoughts and comments below!