Pollinator Habitat Assessment for Mountain and other Rural Homes
How pollinator-friendly is the land around your house?
by Pam Sherman
Do you want to enhance and maintain healthy –and beautiful– native habitat around your home for the benefit of nature and people?
If yes, this doc was written for you, whether you are in the mountains or any other rural area. This doc was inspired by mountain locals’ passion for regenerating and maintaining native habitat.
For this assessment, we recommend the Xerces Society native pollinator plant lists or the Pollinator Partnership native pollinator plant lists for your area and the app iNaturalist.
First we’ll go over some basics about pollinators, plants, and biodiversity. Next we’ll start by observing the micro-habitats you have on your land. Finally, we’ll focus on how you can tell what kind of habitat you have by looking at the plants and flowers, then by looking for the pollinators.
Please take your time and enjoy the process. This can be done quickly if you know your land well or it could take a year. Do it with neighbors!
First: the Basics: Pollinators and Native Plants
Who are the Pollinators?
Bees, wasps, flies, beetles, moths, butterflies, ants and the vertebrates hummingbirds and bats are pollinators. Just for the record, humans are also major pollinators; professional plant breeders do it all the time. For generations it’s been common for gardeners and farmers to hand-pollinate corn and squash, for instance (and there are places in Sichuan, China, where humans pollinate apple flowers because there are no bees left in the area)
Bees are considered the most important pollinators. Careful observers at altitude in the Rocky Mountains think flies may be almost as important; they are usually the major pollinator in the arctic and alpine and are the #2 pollinator after bees below the alpine. There are many different and attractive species of wild flies, just as fascinating as bees; many try to look like bees. Flower flies, fruit flies, and bee flies are just a few of the many fly species who seek nectar for quick energy and become accidental pollinators.
We are focusing on native bees in this post because they are considered the #1 wild pollinator, are well-studied, and they fly during the day. They are a keystone species; the fate of many plants and animals depends on them. When the habitat is good enough for bees in all their stages of development, it will often be good enough for other pollinators and invertebrates needing conservation, with a little tweaking.
Beetles come in next after flies in terms of number of plant species pollinated. (Beetles and flies were the original pollinators millions of years ago). Bats and moths mostly pollinate at night. You can create a “moon garden” for night pollinators if you like. Once you get the hang of creating habitat for the bees, you can do it for the other pollinators.
A word on butterflies: butterflies are crucial to support for reasons in addition to beauty and inspiration. One, caterpillars (ie. butterfly and moth larvae) are a principal food for birds and small mammals. No larvae = starvation up the food chain. Two, the caterpillars of a number of butterfly and moth species are fierce predators of agricultural crop pests; called “beneficial insects,” they are formally employed in Integrated Pest Management on farms and they work informally in home gardens and landscapes; in both systems their work helps cut down on the need for pesticides. (Other types of insects are also important “beneficials.”) Butterflies are not the most reliable pollinators per se, but planting a butterfly garden for adult butterflies as well as their larvae will help the bees and all beneficials.
What a Bee Needs
Abundance and diversity of wild native flowers for their carbs and protein (pollen) and their energy drink (nectar), and secondary metabolites that support their immune function, defense against disease and predation, and even hormones for mating. They also need blooming flowers throughout the growing season and hollow or pithy stems in fall and winter, grasses, bushes, trees, brush piles, rock piles or similar and some warm dry bare ground for shelter, nesting and overwintering sites. The other pollinators have these needs, too (but some don’t eat pollen and many need a water source). Last but not least, they need protection from pesticides—insecticides, herbicides, and fungicides. Without this last protection, the previous needs cannot be met.
Why native plants?
They are wild and tough. Especially if they are local, they are at home here and know their way around. Over hundreds and thousands of years, they have developed special ways of dealing with our climate and the land and efficient ways of working well with each other and the other plants, animals, rocks and water in the ecosystem to get the nutrients they need, protecting themselves from fierce winds, drought, flood, fire, ice storms and more. They are most likely to succeed and to be of use to the pollinators which have developed right along with them over the past thousands or millions of years.
They require much less rich and amended soil than conventional gardeners may be used to. You can plant native seeds in the fall right into raked subsoil; then tamp them down with your feet or a tool so they have good seed-soil contact and don’t blow away in heavy winds . They don’t need fertilizers or a heavy watering schedule, just water for a few weeks to get started. You can also start them inside over the winter. There’s a lot on the internet these days wrt winter sowing tips.
The rule of thumb is to have 70% native plants. There are also plants which are not native to the area, which can do well here in some situations and which can be very useful to generalist pollinators, as can some garden plants,such as those in the cabbage and carrot families, when left to flower.
Why is biodiversity vital?
In Nature, everything is always changing. When one pollinator is down for the count, others can pinch hit. (This is currently the case with native bees stepping up as able where honeybees are having a hard time pollinating crops.) Different pollinators work in different conditions—some emerge in early spring, some late summer, some fly early in the day, some much later, some can fly in light drizzle which keeps the others inside shelters, some are fine in colder weather, some not and so on. We need redundancy—more than one pollinator for each job—for resiliency. Without a range of pollinators our food and forests, our water cycle and its purity and much more would be on a very fragile foundation especially in a warming/changing climate.
Assessment Action
First check the lay of the land: Where are the Micro-Habitats?
Which compass direction is your land facing? South and east are usually sunniest, west and north coldest. The wind usually comes from the West, but can swirl crazily in our usual big storms. Wind from the East means an upslope draft, usually bringing moisture, usually in the Spring.
Where is it warm, dry, sunny, calm, protected from wind, passing cars, trampling, etc. on your land? Where is it cold, wet, shady, windy, least protected? Where is it a mix? Where does the water run on your land? Where does it pool or soak in?
A variety of micro-habitats provide food, shelter, rendezvous and nest sites for a wide variety of pollinators. The more varied the habitat, the more varied the plants and pollinator species can be. This diversity is necessary for resilience to climate change and unexpected weather and other events.
Note on shade: heavy shade means many fewer major pollinators. They need the trees for sheltering and overwintering, but they spend their days in the sun. Look at forest edges, roadsides, sunny patches and gaps in the tree canopy for pollinators gathering food and mating.
Keep a Photo Log
Consider taking photos of each of your micro-habitats or whatever makes sense on your land. Take them of the same area at different seasons, but repeat at the same times each year for a long-term record of how the habitat around your house has changed. Some people enjoy using a macro lens for cellphones to photograph pollinators and other bugs. Use iNaturalist for ID or other app that you know is reliable and accurate for our area.
Now you are ready to start the inventory of your pollinator habitat.
Focus on Plants
Bees need pollen and nectar throughout the season, as some species are active from earliest spring to late in the fall. Bumblebee queens are among the earliest to wake up and need a food source right away to start her brood. Willows and dandelions are famous as early spring food. Goldenrods and purple tansy asters are super hotspot pollinator plants in the late fall.
How many different kinds of mostly native plants that feed bees do you have in bloom at any one time, from early spring through late fall?
This includes flowers on bushes and trees as well as wildflowers as well as flowering food garden plants such as radishes, other cabbage-family crops, basil, carrots, squash, berries, tomatoes, grapes, cherries; let these goes to flower.
Three different kinds blooming at the same time is the bare minimum. Aim for 8. The standard used to be three, but recent studies have shown that 8 can make a substantial difference in habitat quality. Check your plant list (see above) to find out what pollinators use the native plants you have. Or just observe. If it attracts lots of bees, flies or beetles, it’s very useful; you don’t have to look at a list. If you have native trees, birds and butterflies love you; ten times as many caterpillars grow on trees and shrubs than on wildflowers.
All trees and bushes in the pine, oak, willow, cherry/plum and poplar families are known as exceptional larval hosts. Also raspberries and other hollow or pithy-stemmed shrubs are favorite places for above-ground bees to set up brood cells where their young grow from egg to larva to pupa. Some grasses are host plants for butterfly caterpillars. Some butterflies and bees take shelter or spend the winter at the base of bunch grasses (grasses which grow in clumps).
How different are the plants and flowers from each other?
The more varied they are, the more varied the type of pollinators they can attract. Check these categories :
Plant Shape and Size: some plants have tall, rigid stems and outspread branches (trees), some are medium-sized have many stems (shrubs), some are short have one main stem with branches bearing many flowers, some spread across the ground, some twine…How varied are your plants in terms of shape or size?
Flower Size: some flowers, such as those in the parsley/carrot family (Apiaciae) have teeny flowers, perfect for syrphid flies–some of those flies that “dress” like bees– and other pollinators who need teeny flowers. Some flowers are big. How varied are your plants’ flower sizes?
Flower Color: bees have trouble telling red from green, so they tend to stick to blue, purple, white, or yellow plants. The plant Blanketflower aka Gaillardia, is an exception; it has some red on it. (Bees can see UV and this flower reflects a lot of UV so they can see it just fine and use it.) Hummingbirds do like red (though they drink from flowers of other colors and also eat insects on the wing.) It is said that moths like white, while beetles prefer white or green and butterflies like bright colors. What variety of colors do your native plants come in ?
Flower Structure and complexity: some flowers such as penstemons and some in the legume family like lupines have tricky petals which whack bees on the head when they try to get in. (Honeybees don’t much care for this and avoid these flowers, but bumble bees don’t mind.) It takes big pollinators like bumblebees and digger bees (Anthophora) to be able to take this and also muscle down into the flower to get the pollen and nectar. Other flowers like asters and yarrow have an open shape, with pollen and nectar very easy to access by bees with short tongues like the mining bee Andrena and the cellophane bees Colletes and also many flies and beetles. Do you have flowers with different types of structures? What different kinds? How many?
Focus on Pollinator Sign
Is a pollinator using the plants?
In Observing Insect Lives [p.6] author Donald Stokes writes: “Many people see insects but few ever observe their behavior. To observe the behavior of an insect, all you have to do is watch it for at least two or three minutes. At first, this may seem like a long time to watch any one thing in nature, especially if you are used to taking walks and not stopping, or used to just identifying and then going on. But I assure you that in the long run this small investment of time will repay you again and again with wondrous glimpses into insects’ lives.”
Reminder: Bees and other pollinators need trees for sheltering and overwintering, for caterpillars to grow on, for wind and sun protection and some overwinter and pupate in the leaves or needles at the base of the tree. But you won’t observe many flying around in shady areas. They need the sun and sunny areas where more flowers grow. Look in forest gaps, openings, meadows, pastures, roadsides for pollinators gathering food and mating.
Pull up a chair to a bush or wildflower and part the flower petals; get down eye level with the grass and poke around, climb a tree, whatever you like. Do it at different times of day (early morning during and after sunrise, before sunset, and any time in between). A hand lens can help you see in more detail. How many invertebrates do you see? What are they doing?
Note if the insect you see is a pollinator. Sometimes or often you may not know. For instance, some flies and wasps are carrion-eaters primarily, but some can also be pollinators at times.
A great way to learn bees is to use the Bumblebee Watch app. There’s no commitment; just send in a photo of a bee you saw and you will soon get a text telling you what kind of bumblebee (or other bee) it is.
To get used to the many different types of pollinators (and invertebrates) you might see, check out what nature can do as an artist. Go online and search for images of native bees, beetles, flies, butterflies and caterpillars (or other invertebrates). Be prepared for miniscule shiny metallic green sweat bees, blue orchard bees, a caterpillar that was used as a model in horror movie (lady beetle larva), bees that people think are gnats or wasps, flies that look like bees and much more.
Some people get hooked on keeping a life list the way birders do. You could just do bees or just bumblebees. Or butterflies. Or any invertebrate. Note what the invertebrate is doing, share the story with other invertebrate “lifers,” not to mention interested scientists and neighbors. You can join a community science project like Bumblebee Atlas for any pollinator or other invertebrate (and other animals). Or search for others you might prefer.
Specific Pollinator Signs: Check these clues
Pollinators use flower pollen and nectar for food and drink. Observe pollinator hotspot flowers at different times of day over time. When do you see most insects going for pollen or nectar?
Bees use hollow or pithy plant stems as nurseries. Look for dead plants with hollow or pithy stems in the fall.
Leafcutter and mason bee queens use leaves they cut as partitions in their bee nurseries to separate one larva from the next. Look for broad leaves with circles cut out.
Caterpillars who will turn into butterflies (or be fed by birds to their babies) eat the leaves of the broadleaf plants they live on. Look for sign of caterpillar-chewed leaves.
Butterflies often lay their eggs on the undersides of leaves of plants that will host their larva, (which will turn into caterpillars which will turn into butterflies.) Can you find any butterfly eggs on leaves? Might need a hand lens for this.
Bees and butterflies take shelter in grasses and behind leaves and bark on trees. Look at the bottom of bunch grasses and behind leaves and bark on trees at the end of a storm.
Some species of bees use galleries that beetles have carved in woody branches or trunks. Look for bee sign in the galleries.
For bumblebee and other bee nests look in holes in trees and old rodent holes where voles might live or have lived, often in weedy forgotten corners overlooked by humans, maybe around a fence post, where the grass is long and has fallen over, where a vole might feel safe to build a nest. And in fields.
Brushpiles and downed branches, trees, logs, and unraked leaf piles are super hotspots for pollinators to shelter, raise young, or overwinter, especially older wood that’s been down for a number of years and had a chance to decay into the earth a little. What sign do you find and where?
The first field guide focusing on insect sign is the new award-winning Tracks & Sign of Insects and Other Invertebrates by Charley Eiseman and Noah Charney. The authors cover such topics as different types of pupas, webs and other silken constructions, coverings, cases, nests, leaf shelters, cocoons, galls, sign on twigs, stems, rocks and shells, burrows and mounds, tracks and trails and more, describing their experiences in the field as well as documenting sign.
Non-plant places to find pollinators
The earth: Over 70% of our native bees nest in the ground at or below ground level. They prefer no less than 30% sand and no more than 40% clay for the soil structure. Why? so it holds up well, so their nest doesn’t collapse but it also drains well on the rare occasions there is too much water here.
Look on gentle south-facing slopes or flat areas, in an area of full sun, mostly bare of vegetation with just enough bunch grass and rocks to hold it in place. Some bee species like mining bees and sweat bees make tunnels in the same area, so you might find lots of little holes in the earth with little mounds of excavated earth beside them that the bee mom has dug out in making the nesting tunnel. These will be more obvious. Other bees like to be more solitary. Also look in bare soil between plants or any area bare of plants that isn’t compacted.
Rockpiles and old machinery: Pollinators love to nest in the cracks in rock piles, dry rock walls or old rock walls where the cement has crumbled, leaving small holes. Also try between old pavement and the subsoil. And under pebbles, rocks, and boulders.
Even old farm machinery can have small holes and cavities which pollinating insects use for overwintering homes. The same goes for old weathered boards such as those in tumbledown outbuildings or piles of old boards or old fenceposts. Large carpenter bees like to make nests in the soft dead wood of plants like pine and the exposed timber of buildings. See any?
What other pollinator sign catches your attention?
Invasive Plants
Invasive plants take over much or most of the ecosystem, leaving little or no room for other plants. Some that come from far away, whether in the U.S. or outside it, have no local predators here to keep them in check, so are free to run wild. These can be state-mandated invasive weeds or other plants not on the official list that have simplified the land around you (such as smooth brome) so that native plants can barely grow, if at all. Some plants have a built-in runner habit and will take off running and crowding if no other plants or other constraints are keeping them in check. (Read up on a plant’s habits and needs before planting it.)
By definition native plants are not invasive, though you may find one or more taking over an area. Just pull/dig/remove the reproductive parts (rhizomes, flowers, seeds) to cut them back.
If you have a plant that is state-designated as invasive, eradicate it now. Go for it. This is the best time, before it has exploded and taken over. They usually have huge seed production and often deep perennial roots that spread the plant even if you have eradicated all the seed. If you don’t, you may be mitigating it forever. Mow, dig, pull or, if it reproduces by seed as well as by deep rhizomes, weaken by removing the seeds and flowers. If you are doing a formal landscape make-over and your soil is being scraped to subsoil, do whatever your landscaper recommends to remove any invasive weed roots and seeds. If you don’t, you will be battling them for years in your formal landscape design and it will not be fun.
Consult an online reference for best methods for the particular plant in question. When it comes to herbicides: they kill pollinators directly or indirectly. This completely contravenes the goal of creating healthier habitat for pollinators and on up the food chain. Do not use on flowering plants or anywhere near pollinators.
Enhancing Pollinator Habitat
If you find your land lacking, to add pollinator habitat do this: leave the leaves. Also save the stems: leave hollow or pithy stems standing; deadheading some is fine, but leave enough seedheads on for the birds. Add brushpiles and logs, ensuring good soil-log contact for overwintering habitat. Leave stumps, leave snags or trim so they are not in danger of falling or losing a limb when you’re under them. Leave rocks, rock piles, crumbling rock walls, make dry-stacked stone walls, leave old boards and sagging sheds and machinery returning to the earth. Leave some patches of bare ground, however modest, and mud puddles or at least some containers of water for insects, with a twig bridge or rock to help them get out of the container. (Change the water every 2-3 days).
If you want to make these look more aesthetically appealing and intentional (if you live on Main Street for instance), people have found different ways to do this. One is adding paths for people and small viewing areas. Another is putting rock or other borders around the piles, some weather-hardy large urns with wildflowers, outdoor sculpture, benches or chairs for wildlife watching. These can be of stone or hardwood or from willow or equivalent that continues to provide habitat, even sprouting sometimes. A fence of invasive wood (that doesn’t resprout) or native wood that does is also possible and, like twig furniture, can also provide shelter benefit to pollinators. Use humor, have fun.
Some people put up signs explaining this is pollinator habitat. There are many for sale on the internet or they can be homemade or both. Homemade ones can feature adult or children’s artwork depicting plants, pollinators and other appealing critters you are providing for— or anything you want. Signs provide starters for spontaneous, fruitful seed conversations between passersby and homeowners.
Add shrubs, trees, and wildflowers overlapping so there are 3-8 pollinator plants blooming at once from very early spring to late fall.
Once you can assess your home habitat for these tiny wildlife, with implications for charismatic larger wildlife, you can do it anywhere. Whether at home or in the wild, may you have many happy hours with the bees and butterflies, beetles and pollinating flies, those up the food chain and our beautiful plants.
Pam Sherman is on the Wild Ones national Native Plant Resource Team and is a Xerces Society Ambassador.