CORVALLIS, Ore. — Consider adding some flower power to your landscape to bring in the buzz of pollinators to your garden.
"Floral abundance is one of the strongest ways to promote bee diversity in gardens," said Gail Langellotto, the statewide coordinator for the Oregon State University Extension Service's Master Gardener program. “Also, bees forage better for nectar and pollen in warm, sunny spots.”
A showy blend of flowers can charm birds and butterflies as well, she said. But which kinds of flowers should you choose? Langellotto recommends the following:
- Lavenders: Bumblebees, carpenter bees, digger bees and large and small leafcutting bees collect the nectar of this evergreen shrub.
- Pacific or coast rhododendron: Larval host for brown elfin and gray hairstreak butterflies. Hummingbirds, bees and Western tiger swallowtails collect the nectar of this evergreen shrub. Native to the Pacific Northwest.
- Blueblossom: Larval host for pale swallowtail, California tortoiseshell and echo blue butterflies. Bumblebees, carpenter bees, honey bees, digger bees and a variety of small native bees collect the nectar of this evergreen shrub.
- Ocean spray: Larval host for spring azure, brown elfin and Lorquin's admiral butterflies. Bumblebees and a variety of small native bees collect the nectar of this deciduous shrub.
- Serviceberry: Hummingbirds, bees and butterflies collect the nectar of this deciduous shrub. Larval host for Weiddemeyer's admiral butterflies. Native to the Pacific Northwest.
- Russian sage: Honey bees, small carpenter bees and leafcutting bees collect the nectar of this perennial garden plant. The nectar also attracts hummingbirds.
- Red-flowering currant: Important nectar source for early-season butterflies. Nectar also attracts hummingbirds. Perennial that is a native to the Pacific Northwest.
- Zinnias: A wide array of hummingbirds, butterflies and bees collect the nectar. Annual garden plant.
- Sunflower: Longhorn bees, sweat bees, leafcutting bees and bumblebees collect the pollen and nectar of this annual.
- Salal: Larval host for spring azure butterflies. Bees collect the nectar on this groundcover. Native to the Pacific Northwest.
- Catmint: Honey bees, bumblebees, carder bees and mason bees collect nectar and pollen from this perennial.
- Milkweed: Monarch butterflies collect nectar and pollen and lay their eggs on this perennial wildflower. Nectar also attracts hummingbirds. Native to the Pacific Northwest.
Langellotto recommended using a variety of plants to attract diverse pollinators, including plants native to the Pacific Northwest.
"Native plants are fantastic hosts for butterfly larvae, which are completely dependent on native plants to reproduce," she said. "For example, there's a call for gardeners to plant more native milkweed, which is the host plant for migratory monarch butterflies. Without milkweed, monarchs can't complete their life cycle."
In addition to native plants such as milkweed, think about including some ornamental exotics as well in a pollinator-friendly garden, she suggested. For example, several studies in different areas of the country found that the exotic plants catmint and Russian sage are some of the most attractive garden plants for bees, Langellotto said.
"Adult bees are much more indiscriminate than we previously thought and have been found to feed on the nectar and pollen of exotic ornamental plants quite a bit," Langellotto said.
If you are gardening for pollinators, Langellotto advised against using broad-spectrum insecticides, particularly on plants that are in bloom, as well as systemic pesticides. "Systemic" means that the chemical can be absorbed by a plant and move around in its tissues. Broad-spectrum insecticides, which can include systemic insecticides, can kill or harm a variety of "good" insects, in addition to the target pest, she said. When mixed with water and poured on the soil around the base of the plant being treated, systemic pesticides can kill or harm insects for months or years to come, Langellotto said.
“If you’re having an insect issue, consult with your local OSU Extension office for options. Many plants are able to do just fine with low levels of insect damage. Sometimes, it’s just a matter of us adjusting our expectations and tolerating low levels of damage," Langellotto said.
The OSU Extension publication How to Reduce Bee Poisoning from Pesticides (pdf) offers more research-based advice on this topic. To find your local OSU Extension office, go to OSU Extension In Your Community.