Creating nests for native bees
A few months back, I wrote an article called “A Buzz in the Garden,” bringing attention to the plight of honeybees and the role native pollinators play in providing valuable pollination services to farmers and gardeners.
Using this article and other recent publications on bees as a point of reference, a group of talented Master Gardeners created a model pollinator garden at the 2013 Coastal Carolina Fair; the last day to visit that garden is today.
The demonstration garden includes many of the plants mentioned in that earlier article as well as many other features, but one in particular has caught everyone’s attention, and that is the native bee nest boxes.
Approximately 1,200 North American native bee species nest in tunnels and cavities, and the most common types in the Lowcountry are leafcutter and mason bees.
Many gardeners have observed perfectly excised circles cut from leaves in their gardens, which is the work of one of several generations of leaf-cutting bees that use the circles to line their nests. These busy pollinators aren’t particular about where they build, often constructing in unexpected places like ends of garden hoses.
Metallic blue mason bees are important pollinators for early spring gardens, emerging from their nests in January or February here in the South. By May, they have completed their lifecycle. They are such valuable pollinators that commercial fruit and nut producers place mason bee houses around orchards to facilitate pollination.
Unlike social honeybees, these solitary bees make their nests in close proximity to one another, yet separately in small cavities and tunnels found in hollow-stemmed plants and dead trees. Don’t confuse these bees with carpenter bees, which damage wood; mason bees prefer dead wood and “pre-drilled” holes.
The female bees create small apartments within the tube-like holes, building walls between them with bee specific materials such as flower petals, leaves, or mud.
The mother bee lays one egg in each “apartment” or cell, the egg morphs from larvae to adult here so she leaves behind enough food, a mix of pollen and nectar, to feed her offspring until they emerge the following spring. After the exhausting work of building nests and laying eggs, the mother bee dies a few weeks later.
With so much to do in a short time, native bees often tire out in urban spaces seeking pollen and nectar to survive while also searching for places to lay eggs. Gardeners can create pollinator friendly features such as stem nest bundles and wooden nest blocks that provide critical habitats near their gardens.
Stem nest bundles
Provide a simple nest habitat by gathering several 6-8 inch long pieces of bamboo, elderberry, or other plants with hollow, pithy stems cut so that a node provides a closed tube.
Secure the bundle with wire or string or pack the stems into a coffee can or similar vessel, and place the stem bundles horizontal to the ground on a secure surface, protected from wind and rain.
Wooden nest boxes
According to the Xerces society, a conservation group dedicated to pollinators, “(wooden) bee blocks can be made by drilling nesting holes between 3/32 inches and 3/8 inches in diameter at approximate 3/4 inch centers, into the side of a block of preservative free lumber.
The holes should be smooth inside, and closed at one end. The height of the nest is not critical, 8 inches or more is good, but the depth of the holes is important. Holes less than 1/4 inch in diameter should be 3 to 4 inches deep, for holes 1/4 inch or larger, a 5 to 6-inch depth is best.
“Bee hotels” provide an overwintering habitat for other species such as ladybugs and wasps, both beneficial to the garden.
You can create a high occupancy “bee hotel” by combining several types of nesting material under one roof. These will require more sanitation and maintenance due to a higher population of bees in one place but are worth the trouble for gardeners with many fruits and vegetables in need of pollination.
Experts on native bee conservation with the Xerces Society say that nest blocks and bundles can attract and support native bees, but without regular sanitation, they can do more harm than good.
The unnaturally high bee populations found in these blocks can create unsanitary conditions leading to disease issues with negative impacts.
For more information on sanitation recommendations check out this factsheet: http://bit.ly/bCN5ZA.
Making a native bee nest bundle will be just one of the programs at the second annual Garden Gathering at Cypress Gardens on Saturday.
Clemson Extension and Cypress Gardens will offer lectures and workshops about gardening for wildlife and pollinators.
Registration includes lunch, handouts and entry to Cypress Gardens.
Registration is $60/individual (South Carolina Master Gardener Discount $55). Sign up at www.regonline.com/thegardengathering.
Arbor Day Tree Sale
The Tri-County Master Gardener Association and Clemson Extension Service are partnering for its first Arbor Day Tree Sale fundraiser this year.
Plants, which include fruit and ornamental shade trees and shrubs, must be pre- ordered by Nov. 18. A printable order form is available at www.clemson.edu/ extension/county/dorchester/index.html.
Contact Derrick Phinney at 563-0135 or Janet Litton, email@example.com.