We can all do more (or less) to manage our landscapes for pollinators. Resist the urge to clean up your landscape; instead, leave natural items such as plant stems, logs, dead trees and leaves. Pollinators need undisturbed, pesticide-free, habitat-rich, plant diverse landscapes in order to thrive.
Here are some ways we can all improve pollinator habitat in our own yards:
A standing dead tree provides nesting sites for cavity-nesting pollinators including bees, wasps and beetles.
Nesting Habitat
CAVITY-NESTING POLLINATORS
Approximately thirty percent of bees and some wasps nest in cavities, usually preexisting cavities. Small and large carpenter bees will excavate their own cavities in wood or plant stems. Most pollinators seek out existing cavities. Cavity-nesting sites can occur in plant stems, holes in wood such as standing dead trees or holes in rocks.
A leafcutter bee, Megachile sp. carries a piece of a leaf into its nest in a rock cavity.
Provide cavity-nesting sites for pollinators by:
Leaving standing dead trees (snags) in the landscape
Leaving or adding downed logs (nurse logs) lying on the ground
Leaving perennial stems standing for the winter to protect exisiting cavity-nesting pollinators
Carefully cutting perennial stems in large pieces and laying them on the ground. You can also poke one end of the cut stem into the ground in late spring to create a nesting site.
Adding or leaving rocks with holes for nesting cavities
An aggregation of mining bee nests (Andrena spp.) on a sandy slope.
GROUND-NESTING POLLINATORS
The remaining seventy percent of bees nest in the ground, typically excavating nests in bare soil or sparsely vegetated places under plants. No, these are not the same nests as the aggressive, ground-nesting yellowjacket wasps that nest in colonies. Native ground-nesting bees do not aggressively defend their nests because the majority has just one solitary female who is excavating and provisioning the nest. All ground nests are excavated by females, preferring sandy, loose, well-drained soils. Many ground-nesting bee nests resemble ant hills with excavated soil piled around the nest entrance. Ground-nesting bees often nest in aggregations with many nest entrances clustered together.
Bumble bee queens typically choose a nest site below ground, often in abandoned rodent holes.
Provide and protect ground-nesting sites for pollinators by:
Preventing soil disturbance – no tilling or soil grading
Preventing soil compaction – no heavy equipment or foot traffic near nesting sites
Leaving areas of bare soil, especially on slopes/banks
A decaying log and leaf litter: two nesting/overwintering sites for pollinators.
OVERWINTERING SITES
Butterflies, moths, beetles, flies, bees and wasps overwinter in various locations in our landscapes. Besides the cavities and ground nests above, leaf litter is one of the most important places that pollinators seek out refuge. Butterflies and moths use leaf litter as protection for various stages of their life cycles including as adults, pupae or larvae. Moth larvae frequently spin cocoons in late fall to overwinter in leaf litter on the ground near their host plants. Remember to leave leaf litter in your landscape!
Foraging Resources
Use a variety of flower colors and forms.
Continuous Succession of Flowering Plants
Pollinators need a continuous succession of flowering plants from spring through fall. To achieve this, evaluate your landscape to determine if you are missing some flowering plants for a particular part of the season and plant to fill those gaps.
Diversity of Native Plants
Use a diversity of native plants with different flower forms and floral resources so all pollinators can access resources. Include butterfly & moth larval host plants in your plantings.
Water
Provide a shallow source of water and refresh every 5-7 days (to kill mosquito larvae and prevent disease).
Plant Selection & Placement
Many of the same plant clustered together makes foraging more efficient for pollinators.
Invasive Species
Remove invasive plant species while minimizing soil disturbance
Use Local Genotypes
Use local native plant communities as cues for plant selection then purchase plants that have been grown locally
Reduce The Size of Your Lawn or Create a Pollinator Lawn
Replace a portion of lawn with forage plants or incorporate forage plants in your lawn
Visually Attractive Planting (For Pollinators)
Plant forage plants in masses to create better visual attractants for pollinators
Pesticide Poisoning Prevention
Native plants also attract beneficial insects that prey on ‘problem pests’. Both solitary and social wasps visit flowers for nectar and help keep problem pests in check.
Purchase plants from retailers that do not use systemic insecticides including neonicotinoid-based insecticides during nursery production. If systemic insecticides have been used, the plants potentially remain harmful to pollinators for several months to a few years after you plant the plants in your landscape
Determine what the problem is first, learn everything you can about the insect or disease, then make an informed decision of how best to minimize pollinator poisoning.
Use non-chemical methods to control pests whereever possible
Restrict or eliminate pesticide use, especially when forage plants are flowering. Most insecticides, some herbicides and some fungicides are harmful to pollinators.
© 2014, Heather Holm. All rights reserved. This article is the property of Native Plants and Wildlife Gardens. If you are reading this at another site, please report that to us