Plant a Pollinator Paradise
A quick Google search for “pollinator gardens” yields a bevy of results: YouTube videos, books, articles and many items for sale – preplanned gardens, seed mixes and something called a push garden — “a curated selection of perennial wild flower seeds” — that is one of Oprah’s favorite things and is sold out on many sites. Clearly something is going on. Gardeners are eager to help the pollinators who are facing threats to their survival. With no offense to Oprah, it takes more than a push garden to truly create plantings that benefit pollinators. It is first important to understand who the pollinators are and then create in your yard, not just a garden, but a habitat that gives them the resources they need. Your yard is an ecosystem whose health and functionality depend on how you manage it. By working to benefit the living things that exist in your ecosystem, you will create the biodiversity, or variety of living things, that leads to an ecologically sound environment. Here are the basic steps you can take to attract pollinators and make your home a paradise for living things.
KNOW THE POLLINATORS
Wind, water, and animals all help plants reproduce by spreading pollen from the male to the female parts of a plant, creating seeds or fruit. Of the animal pollinators, bees are by far the most efficient and therefore most important. To feed their young, bees actively collect pollen on their legs or abdomens, and by doing so, transfer the pollen from the anther to the stigma, fertilizing the flower. Butterflies, moths, flies, beetles, hummingbirds, and even wasps also carry pollen as they move from flower to flower sipping nectar. Trying to meet the needs of each of these creatures sounds daunting, but if you focus on creating a habitat for bees and butterflies, most other insects will find the habitat suitable for their needs. An effective pollinator habitat needs the right flowering plants that provide nectar and pollen as well as appropriate leafy plants that feed caterpillars, the larvae of butterflies.
REDUCE THE LAWN
Turf grass covers an area three times larger than any other irrigated crop in the U.S., according to the International Society for Photogrammetry and Remote Sensing, 2016. Compared to bare soil, lawns prevent soil erosion and filter water. These positives, however, are counteracted by the negative environmental impact from the chemical pesticides, herbicides, fertilizers and water that lawns require. Add in the air and noise pollution from mowers, blowers, and weed eaters, and the obsession with lawn is hard to understand. From a pollinator standpoint, lawns are a food desert. Even if lawn has clover or weeds in bloom, there is little for a bee to eat. The first step in creating a habitat for pollinators is to reduce areas of lawn. Tearing out the entire lawn would be daunting and is not necessary. Start small. Are there patches of lawn that could be re-planted with understory trees, shrubs and insect-attracting perennials? Can existing beds be expanded? Can single trees be surrounded by beds of flowering ground covers? Over time, you can link these garden pools to one another and create a bountiful habitat, with lawn only in the areas you need for walking, sitting or playing.
PLANT NATIVE PLANTS
The USDA Natural Resources Conservation Service defines a native plant as “a plant that is part of the balance of nature that has developed over hundreds or thousands of years in a particular region or ecosystem.” NRCS/Native, Invasive, and Other Plant-Related Definitions The most important word in this definition is region. Because the native plants and insects of a region evolved together, they have formed relationships that are the basis of a complex and sustainable ecosystem. Native plants provide food that the pollinating insects require, and in turn, the insects provide the pollination services the plants need to produce seeds and fruit; it’s the web of life that keeps the world humming. Research by Doug Tallamy at the University of Delaware has shown that native insects not only prefer native plants, some species can only feed on certain species of native plants. (Douglas Tallamy, Bringing Nature Home, Timber Press, 2007). Unfortunately for native insects, most of the ornamental plants we have loved and planted in our gardens have been introduced from other areas, notably Asia. While beautiful, these introduced plants did not evolve with the insects of our region. Many of them do not provide food for the insects and so do not contribute to the biodiversity needed for a healthy ecosystem.
When creating a habitat for pollinators, there is no need to remove every non-native plant from your landscape. Many pollen and nectar eaters, such as bumblebees, have a wide diet and throng to non-natives such as nepeta, Russian sage, lavender, and herbs. Examine your garden and see where the bees are gathering to decide what to keep and what to replace. If you decide to retain exotics such as crepe myrtle, iris, and peonies that do not provide much for pollinators, remember that they are for you. Keep adding natives so that your garden becomes 70 – 80% native species for the pollinators. Natives are especially important for caterpillars, who can only eat leaves from certain plants. A switch to natives will not be disappointing; a garden of viburnum, witch hazel, bee balm, penstemon, liatris, and turtleheads — teeming with life — will be just as beautiful as any other garden. Native plants have adapted to the soil and climate of their region so typically need less supplemental watering and fertilizing, which is healthy for the environment and a boon to the gardener.
Often native plants are associated with meadows, which, by their nature, can be wild and untidy. But there are native trees, shrubs, perennials and grasses appropriate for every situation. They can be incorporated into a formal landscape as well as a casual cottage garden. Because natives are specific to certain areas and you are trying to create a functioning habitat of interrelated plants and insects, it is worth learning which plants are native to your area. Take the guess-work out of your planning by using one of the online native plant finders. The National Wildlife Federation identifies natives appropriate for you based on your zip code. Or you can try a search at Va.Dept.Conservation & Recreation/Native Plant Finder, which is organized by region of Virginia (Mountain, Piedmont, Coastal Plain) and allows you to refine your search by type of plant, amount of sun, etc. Even more refined searching is possible with the Piedmont Natives Plant Database, which allows you to focus on a particular county and to specify types of pollinators desired, as well as soil type, flower color, bloom time, and other variables. Each plant is then linked to the USDA Plant Database, which allows you to look at photos of the plant.
When choosing native plants, know the differences among species, cultivars and hybrids and how they affect the overall effectiveness of your garden as a habitat for pollinators. For more information on this topic, refer to the article “Native Species Plants or Cultivars of Native Plants – Does it Matter?” in this month’s issue of The Garden Shed.
PLANT FOR A SUCCESSION OF BLOOMS THROUGHOUT THE SEASON
Native bees have varied life cycles. They emerge from their nests, forage, mate, and build nests at different times throughout the year and have varied lifespans. On March 18, I saw a mason bee, newly-emerged from its nest and looking for the first meal of its adult life. A few short weeks after emerging, the mason bee will have mated, built a new nest, provisioned it with pollen, laid her eggs, and died well before spring has turned into summer. Those larvae will rest in the nest until next spring. The first bumblebee of the year appeared in my garden March 23. She had mated and retreated to her nest in October or November to hibernate through the winter. Now hungry and ready to lay her eggs and start a new colony, she staggered unsteadily, looking about the leafless landscape for a bit of nourishment. Provide a feast for bees by planting for overlapping blooms, from very early spring through late fall.
Early spring, when the first bees appear, is the most challenging time for them and the time most likely to be neglected by the gardener. The blooms of the tall trees often found in the home landscape, Acers (maple), Quercus (oaks) and Liriodendron (tulip trees) are an important food source in early spring. Consider adding early-blooming understory trees and shrubs such as Amelanchier (serviceberry) Cercis canadensis (redbud) Cornus (dogwood) , Lindera benzoin (spicebush) or Aronia (chokeberry), to supplement the food provided by the big trees. These native trees and shrubs are also host plants to many butterfly larvae. If you have room, plant some pawpaw trees in the dappled shade of larger trees for a three-fold bonanza, The brownish, drooping flowers are pollinated by beetles and flies rather than bees, the paddle-like leaves are food for the beautiful zebra swallowtail butterfly, and the resulting pawpaw fruit is a delicious treat for the gardener. Before you start planting, take advantage of growing advice on these shrubs and trees in previous issues of The Garden Shed:
Learn about and plant spring ephemerals such a spring beauty, hepatica, bloodroot, Dutchman’s breeches or trillium along with the more common bleeding hearts and Virginia bluebells. Scattered among early blooming bulbs, they provide food for the early pollinators and their blooms are a welcome sight to the gardener after a long winter. The ephemerals grow in the part sun of the woodland garden or under mature trees and then recede when leaves overhead cast shade. To the Victorians, violets were a symbol of modesty and fidelity. Let these sweet, old-fashioned flowers ramble in your beds or lawn as an early source of pollen for bees as well as a host plant for fritillary butterflies.
As the seasons progress, keep the feast going by planting these easy-to-grow and readily-available pollinator attractors:
|Mid to Late Spring||Early Summer||Mid-Summer||Late Summer and Fall|
|Wild Geranium||Spiderwort||Blazing Star||Rudbeckia|
|Creeping phlox||Coreopsis||Mountain Mint||Aster|
|Baptisia||Asclepias||Joe Pye Weed||Goldenrod|
As your fascination with pollinators grows, (as it surely will), expand your knowledge by seeking out local native plant societies and native plant nurseries to learn about less-common, but equally beautiful plants such as skullcap, wild petunia, cup plant, Culver’s root and New York ironweed. For an easy-care pollinator paradise, make room for summer-blooming shrubs such as blueberries, sweetspire, shrubby St. John’s wort and elderberries that bring the pollinators in droves. For growing information about blueberries and elderberries, consult Blueberry Cultivation/The Garden Shed 4/2019 and Elderberry/The Garden Shed 3/2020. A native viburnum belongs in every garden. The leaves are hosts for caterpillars, the flowers feed bees and butterflies, and the fall berries feed migrating birds.
Go exploring at the following websites: the Virginia Native Plant Society, Va.Native Plant Guides, the North Carolina Native Plant Society, https://www.ncwildflower.org/ and the Maryland Native Plant Society, https://mdflora.org/, all of which offer guides for the best native plants for each region. Another excellent source is the Xerces Society, which provides a wealth of information on attracting pollinators and regional lists of native plants, xerces.org/Pollinator Plants: Mid-Atlantic Region.
ATTRACT DIFFERENT TYPES OF POLLINATORS WITH A DIVERSITY OF FLOWERS
Bees have various sizes, shapes, tongue length, body strength, and flight range. A successful pollinator garden will include a variety of flower shapes to accommodate these differences. Bees with short tongues will forage on flatter, more open composite flowers such as shrubby St. John’s wort while burly bumblebees can muscle their way into tubular flowers such as penstemon and turtlehead. Only pollinators with long tongues, such as bumblebees, butterflies, and moths can reach deep into the long tubular flowers of monarda fistulosa. Butterflies pollinate phlox and gravitate to the composite flowers of Joe Pye Weed. Hummingbirds, with their long probosces, need the long tubular flowers of salvia, cardinal flower, and Monarda didyma.
Flower color also plays a role. Bees are attracted to white, yellow, blue, and purple flowers, but, as they see light on the ultraviolet spectrum, cannot see and so seldom forage on red flowers. Hummingbirds are well-known for their attraction to the color red, but also go to blue and purple blossoms. Moths, mostly flying at night, are attracted to white, or other pale, sweet-smelling flowers.
Remember that nectar and pollen are only half of the story. Be sure to provide host plants that feed the caterpillars. In addition to the trees and shrubs already mentioned, include milkweeds and butterfly weeds for the monarch, pussytoes for the American lady, and turtleheads for the Baltimore Checkerspot. Bumblebees and many other native bees are generalists and can forage on several flower species. Other bees are specialists and can only forage on specific species. Vegetable gardeners are familiar with the squash bee that pollinates squash plants. The Spring Beauty bee, Andrena erigeniae, collects pollen exclusively from the ephemeral Spring Beauty (Claytonia virginica) and the closely related Claytonia carolinana.
It is enough for most gardeners to simply know that providing a variety of native plants with various blooms appearing over a long season is needed to meet the spectrum of pollinator characteristics. But to delve more into the specifics of who eats what, investigate the research of Heather Holm on the interactions between native pollinators and native plants: Pollinators of Native Plants (Pollinator Press, 2014) and Bees: An Identification and Native Plant Forage Guide (Pollinator Press, 2017). Refer to Douglas Tallamy, Bringing Nature Home for regional lists of caterpillar hosts.
PLANT IN MASSES
Bees exhibit a characteristic called floral constancy. They visit and collect pollen from one variety of flower on each foraging trip. While a big bumble bee can fly up to a mile, smaller bees may only manage a range of 500 feet. Make life easy for them by siting your pollinator gardens close to possible nesting sites and planting one kind of flower in a large swath; three feet square is best. In a small garden, it might be difficult to devote a square yard to one flower, especially when you want to spread the buffet throughout the season. But do the best you can to plant in clumps and avoid the singletons. Remember, planting for pollinators gives you permission devote more and more of your landscape to flowering plants, and every gardener should be happy to do that.
PROVIDE NESTING SITES
Seventy percent of native bees nest in the ground. Others are tunnel nesters, snuggling into abandoned beetle tunnels in stumps and snags, or chewing into the hollow stems of plants. Some find homes in the crevices of stone walls. Bumble bees live in colonies underground, in old mouse tunnels or under tufts of grass. Help them find a home by leaving some areas of ground in a dry, sunny location free of mulch. If you have room, place old stumps or logs in a sunny area. They may already sport beetle tunnels, but if not, drill a few holes in the wood.
In the fall, allow fallen leaves to stay on your garden beds. These will nourish the soil and provide overwintering sites for caterpillars and other insects. Avoid the temptation to clean up your perennial garden in the fall and leave the stems standing through the winter. Those pithy stems might be harboring a snug nest of bees. It will be tempting to start cleanup at the first sign of warmth in the spring, but resist that urge in order to give insects time to awake and become active. Wait until temperatures are consistently warm, and then stagger your cutting back over a few weeks. If the garden looks too messy for your taste, cut the stems close to the ground and leave them lying in the garden for a while. Not only will this give the creatures time to emerge, you will be adding good organic matter to the soil.
Densely-packed brush piles provide good habitat for bees as well as shelter for birds, chipmunks, and other wildlife. Even if your property is small, find an out-of-the-way place to bundle and stack the branches from your pruning efforts. If you have been reducing your lawn and creating a lush habitat of trees, shrubs and perennials, it will be easy to conceal that brush pile.
Every garden center and catalog now feature bee hotels for mason bees, but it is easy to construct your own. Drill holes, between 3/32” and 3/8” in diameter in a block of untreated wood. The holes should not go all the way through the wood, so the nest is closed at one end. Alternatively, gather some hollow tubes made from bamboo or cardboard, and tightly pack them into a can, bucket, cup, or wooden structure. The tubes should be 6-8” in length and closed at one end. A roof over the top to deflect rain and a wire grid to discourage bird predators will give the larvae a better chance of survival. Place the nests 3-6 feet above ground, in a sheltered spot, facing east or southeast to get the warmth of the morning sun. You will know bees have taken up residence if you see the opening sealed with mud. Leave the nest alone all winter. The eggs will hatch, the larvae will feed on the pollen the female has deposited and then will emerge as adults in the spring. When you see that the mud has been broken through, replace the tubes with fresh ones and wait for a new crop of bees to take up residence. For detailed instructions on constructing bee nests, see the Xerces Society recommendations at xerces.org/Nests for Native Bees.
Pollinator decline can be attributed to loss of habitat, degradation of existing habitat due to the proliferation of invasive species, and to the use of pesticides. Foraging bees can absorb pesticide toxins through their exoskeletons, might drink poisoned nectar, or eat pesticide-covered pollen. Even if they are not killed outright, bees exposed to poisons may suffer neurological damage that prevents them from finding their way back to their nest or makes them unable to fly at all. Secondary damage may occur to the larvae who eat the tainted pollen. (Xerces Society, Attracting Native Pollinators, Storey Publishing, 2011).
Systemic pesticides, such as those in the category called neonicotinoids, remain in plant tissue and can cause harm long after application. https://www.xerces.org/pesticides/risks-pesticides-pollinators For a deeper study of neonicotinoids, see “Another Pesticide Controversy: Neonicotinoids and Pollinator Decline,” in a prior issue of The Garden Shed, The Garden Shed May 2019. There is very little need, if any, for the home owner to use pesticides in the lawn or garden. Pesticides, even those derived from natural sources such as pyrethrums, are broad-spectrum and kill anything they contact, including bees and other beneficial insects. If you create a healthy, diverse landscape with a preponderance of native plants, you will not only attract pollinators, but will also attract the birds and beneficial insects that keep the predators in check. Create a habitat that nourishes all living things, and find the balance that will reduce or eliminate the need for pesticide.
If undesirables do appear, identify the pest so you can understand its life cycle, then decide how much damage you can tolerate. Integrated Pest Management, The Garden Shed May 2020. A few chewed leaves might not be noticeable. Will the pest soon die anyway? Can you wait to see if a beneficial shows up to take care of it? Hand-picking or blasting the pest with a spray of water may be all that is needed. For more information on attracting beneficial insects, check out last month’s article, Natural Pest Control, The Garden Shed June 2020. A large infestation on a valuable tree or shrub might require the services of a professional. When buying nursery plants, check the label to be sure they have not been treated with a systemic pesticide. Reducing Pesticide Use in the Home Lawn and Garden, is an excellent guide for homeowners on preventing and dealing with pests in the landscape. https://www.pubs.ext.vt.edu/450/450-725/450-725.html.
SITE YOUR POLLINATOR GARDEN
The adage of right plant in the right place is also true for pollinator gardens. Be sure to match your plants to the conditions of your site – wet or dry, sun or shade. Most pollinators need sun to warm up and be active so pollinator-attracting plants are typically sun lovers. Selecting a sunny spot will yield the best results, but do not be discouraged if your property is shady. Those early-blooming ephemerals will be just right for you. Can you garden along the “edge” of that shady area? Plant shade-loving wild geranium, heuchera, and tiarella for spring bloom. Native azaleas, Calycanthus (sweetshrub), Itea (summersweet) and Clethra (sweet pepperbush) tolerate shade, and their common names give a hint to another benefit of including them in your landscape. Summer bloomers such as Joe Pye weed and fall-blooming white wood aster and zig-zag goldenrod do well in part shade. If you do not have a yard at all, you can still attract pollinators by planting native plants in pots. Remember that the roots of native plants go deep, so select large containers. Because natives are perennials and will not bloom all summer, choose plants that will look good after bloom has ceased, such as heuchera for shade or threadleaf coreopsis for sun. Look for cultivars of natives that have been bred to be smaller such as Pixie Meadowbrite coneflower or Viette’s Little Suzy black-eyed susan. Gather a collection of pots, each with a different perennial of various heights and bloom times and move them around to change the scene and feature the current bloom. A tall native grass in a pot would make a great back-drop to a collection of flowering plants.
GROW FROM PLANTS OR FROM SEED
The simplest way to create your pollinator habitat is to buy plants or plugs from a reputable garden center or native plant nursery. This can be pricey and some gardeners, especially if designing a larger meadow type planting, will prefer the challenge and excitement of starting from seed. Planting from seed will also assure that you are getting the exact species you want. If seeding is your preferred method, stay away from pre-mixed collections unless you know they have been mixed purposely for your ecologic area. Native seeds also have specific germinating requirements. Some need a period of cold called stratification, some need moist conditions, some need light, some need dark. Will you start your plants in flats or direct-sow in the ground? Before launching into seeds, Consult the Missouri Botanical Garden write-up on Native Seed Propagation Methods, Missouri Botanical Garden. The Ecological Landscaping Alliance also offers good information on starting natives from seed, Ecolandscaping.org/Native Perennials from Seed. The best approach for growing from seed is to start in a small area and then expand when you see success. Remember that native plants want to spread. Start your garden, whether from plants or seeds, and let the pollinators do their work. Over time your garden will increase naturally and eventually become a pollinator paradise.
GET INVOLVED IN POLLINATOR CONSERVATION
Become a citizen-scientist and gather data for scientists studying the conservation needs of pollinators. For example, you can help track bumble bees by photographing those in your yard and submitting your photos for identification by experts at Bumble Bee Watch, Bumble Bee Watch.
Upload your photos and be counted by joining Bumble Bee Watch, Bumble Bee Watch
Register your garden with the Great Sunflower Project, https://www.greatsunflower.org/
Sign the pollinator pledge, Xerces.org/Pollinator Pledge
REFERENCES AND MORE INFORMATION
Attracting Native Pollinators, Xerces Society, Storey Publishing, 2011
Bringing Nature Home (Douglas Tallamy, Timber Press, 2007)
Nature’s Best Hope (Douglas Tallamy, Timber Press, 2019)
Habitat for Wildlife, Virginia Department of Game and Inland Fisheries, https://www.dgif.virginia.gov/wildlife/habitat/
Native Pollinators and Plants for Pollinators, USDA National Resources Conservation Services
100 Plants to Feed the Bees, Xerces Society (Storey Publishing, 2016)
Pollinators of Native Plants (Heather Holm, Pollination Press, 2011)
The Bees in Your Backyard, Joseph S. Wilson and Olivia Messinger Carril (Princeton Univ. Press, 2016)
National Wildlife Federation, https://www.nwf.org/
Pollinator Partnership, https://www.pollinator.org/
U.S. Fish and Wildlife Service https://www.fws.gov/
Xerces Society for Pollinator Conservation, htttps://www.xerces.org/
“Specialist pollinators deplete pollen in the spring ephemeral wildflower Claytonia virginica,” Ecology and Evolution, vol. 6,15 5169-77 (Jun. 2016)