Forest botanist shares planting tips to protect pollinators
OLYMPIA, Wash. – March 5, 2018 – I’ve been out and about on the Forest of late, and even though March has just begun, some of our native plants are beginning to show signs of life! Indian plum (Oemleria cerasiformis) is in full glorious bloom right now and there’s a red flowering current (Ribes sanguineum) in my yard that looks like it could bloom any day now. Both of these native shrubs are important parts of the ecosystem on the Olympic National Forest, but they are also beautiful plants that are great additions to western Washington gardens. Not only do they look nice, but they also benefit pollinators and other wildlife around your home by providing food and shelter for these animals.Many of the pollinators that live on the Olympic National Forest might also find their way to your garden if you give them a reason to visit! Below are a couple of links to plant lists – both native and horticultural – that are attractive to a variety of pollinators, and that grow well in western Washington. Try some of these this year – especially the natives! – and see who shows up:
- Native plants: http://www.wnps.org/landscaping/herbarium/index.html
- Horticultural plants: http://www.greatplantpicks.org/plantlists/search/
- View more tips on gardening for pollinators, at http://www.fs.fed.us/wildflowers/pollinators/gardening.shtml!
Who pollinates our plants?
Bees aren’t the only pollinators out there; butterflies, moths, birds, beetles and many other animals also pollinate plants. Some plants don’t rely on animals at all, but rather are adapted to rely primarily on the wind. Plants that are wind pollinated typically don’t have showy flowers – think grasses, oaks, alder, and our native hazelnut (Corylus cornuta). Plants that rely on animals for pollination typically have showy, smelly, and/or nectar producing flowers.
Some of our most conspicuous pollinators in western WA include hummingbirds, who transfer pollen from plant to plant “by accident” while they forage for nectar. Plants that rely heavily on hummingbirds for pollination will often have anthers – the pollen producing structures – that stick out of the flower so the hummingbird rubs against them when they drink nectar secreted from glands deep in the flower. The pollen then sticks to the hummingbird and is carried to the next flower it visits.
Our native bumble bees also make an appearance – keep an eye our native rhodies when they start to bloom this spring and maybe you’ll see “buzz pollination” in action. Some plants – including rhododendrons and azaleas – have evolved to be very conservative with their pollen and only release it under very specific circumstances, namely by buzz pollination.
These plants have anthers with a small pore at their tip where pollen is released. This happens only when and insect – usually a bumblebee – vibrates their flight muscles which produces a high-pitched buzzing sound; if you’re near a rhodie in spring, you’ll probably hear it. These vibrations cause the pollen to be released out of the pore in the anther, often explosively!
The bumblebee then harvests the pollen, which is a nutritious food it uses to stock its’ nest. Some of that pollen will stick to its’ furry body and is then transferred to the next flower it visits. If you have a tuning fork (and who doesn’t), you can simulate this whole process on your own; I’ve heard that an electric toothbrush also works, but your neighbors may look at you funny after seeing you stick a toothbrush into the rhodies in your yard.
Honey bees are also a common visitor to our gardens and – although they are a non-native species – they are extremely important to agricultural crops like cherries, blueberries, apples, and many others. There is an entire industry dedicated to moving honey bee hives from crop to crop, which takes truckloads full of hives from one end of the country to another. Remember that truck that was full of bees that over turned on I-5 in Lynwood last year? That truck was likely headed to eastern Washington after spending time in California’s almond orchards, which annually require a staggering 31 billion honeybees (there are approximately 7.4 billion humans on the Earth, just to put that in perspective) to pollinate 810,000 acres of almond trees. The almond bloom in California is a massive event in the commercial beekeeping world, with truckloads of honey bees arriving from all across the country.
Butterflies are another type of pollinator, but represent just the adult stage in the lifecycle of these important insects. Before there are butterflies, there are eggs, larva (caterpillar), and pupa (the chrysalis). Each of these stages have different requirements including a food source and shelter to lay eggs and pupate.
Often, a single butterfly species will require different plants depending on what stage of their lifecycle they are in, and different species require different sets of plant species. Here are some tips on how to attract butterflies to your garden by providing the habitat elements they need.
Please remember, DO NOT PLANT BUTTERFLY BUSH (Buddleja sp.)! Even though this plant is extremely attractive to butterflies, it is a noxious weed and is becoming a real problem in riparian areas in western Washington, Oregon, and other parts of the country.
Cheryl Bartlett is a USDA Forest Service botanist on the Olympic National Forest in western Washington.