Five Ways to Make Your Yard More Biodiverse

Olive clubtail dragonfly resting on Mountain ash (Sorbus scopulina).

 

Every 30 seconds in the United States, a football field-sized chunk of natural area disappears due to development, according to research from the Center for American Progress. Most of the natural areas lost in the past two decades were on privately-owned land, which accounts for about 60% of all land in the country. Clearly there’s much work to be done, since only 3% of protected areas in the U.S. are on private land. Currently, only 12% of all U.S. land is protected, which is very bad news for biodiversity. 

Scientists see the goals set by the International Convention on Biological Diversity — protection of a mere 17% of land and 10% of oceans by 2020 — as completely inadequate to handle the Sixth Mass Extinction and the climate crisis. To stop the crumbling of biodiversity — defined as all the organisms on earth, well as the diversity of ecosystems in which they are found, and the genetic diversity within each species — efforts are now behind “30×30”, a global goal to protect 30% of Earth’s land and water by 2030.

President Biden issued an executive order soon after taking office that requires agency leaders to submit input and strategies for how the feds can conserve at least 30% by 2030. Reversing the cuts made by the Trump administration and targeting expansive areas will certainly have the quickest effect, but all important habitat ought to be saved or restored. If you feel hopeless or sickened by the extinction and climate crises made worse by unrestrained development, even a 30 by 30 foot space at home will help. We can’t put it off any longer.

Here are some objectives as you move forward: 

1. Focus on local native plants after removing invasives. There’s nothing terribly wrong with growing a few of your favorite plants—for example, I love certain clematis vines and irises, and I grow organic food to eat. But those plants don’t provide much, if any, benefit for wildlife, so a large portion of the remaining plants I’ve chosen are native species, most of which belong in my area and might grow together in their natural state. Besides being low maintenance (when properly sited), they are absolutely essential to creatures who developed special relationships with them over millennia.

Native species are superior to introduced plants not because they’re trendy or due to some prejudice or because I say so. Simply put, native plants depend on native wildlife and vice versa (when they are in the appropriate place—that is, areas where they evolved together). They’re adapted to local environmental conditions and their value is not based solely as a resource for humans or on appearance (although their beauty is remarkable!).

Plant diversity is strongly associated with species richness, including healthy insect-dominated food webs. As the essential structural and functional base of many of the world’s ecosystems, most insects are “specialists”—they can only survive with certain species of plants that they evolved with (as opposed to “generalist” species that can use many plants). For example, butterflies and moths need certain host plants that provide food for their young, and many native bees forage for pollen only on specific plants at specific times of year. Myriad other insects are able to use only specific native plants; if those plants aren’t around, the insects’ decline or disappearance adversely impacts ecosystems and other animal populations since specialist and generalist insects and other arthropods supply food for other wildlife. Besides habitat destruction and climate chaos, insects are challenged by additional stressors, including insecticides, herbicides, introduced species, and light pollution. To make things worse, stressors often happen simultaneously. A 2019 global review revealed that 40% of insect species could become extinct in the next few decades, with a staggering 2.5% decline in insect biomass per year, and warned of a catastrophic impact on the earth’s ecosystems. In 2020, researchers found that Earth lost more than 25 percent of land-dwelling insects in the past 30 years

Growing natives is an act of compassion for wildlife at our mercy. It helps to think of animals as individuals with emotions and personalities, not just species. Like us, they want to avoid suffering and live a decent life, and most need native plants in order to do so. Animals such as birds and frogs that eat insects directly are of course negatively affected, but other species are as well. Bobcats, for example, are obligate carnivores, but they need native plants since they typically eat animals that consume insects or plant matter. 

Buy plants propagated from source material that originated as close as possible to your site. Using such “local genotypes”  helps ensure that you get plants that are well adapted to your area and preserves the genetic diversity that helps plants (and animals) adapt to changing conditions. Ask growers and nurseries about their sources if you’re unsure.

2. Minimize lawn and be bold when it comes to sizing garden beds. The more space we allocate for native plants, the better. Lawn is an unnatural monoculture that provides almost no support for wildlife, so if it’s not needed, let it go. You can remove it with a sod cutter or spade, but to preserve precious topsoil, cut it short, then cover it with a half dozen layers of overlapping newspaper or a layer of cardboard with holes punched in to ensure drainage. Cover with leaf compost and allow it to break down over many months.

To get ideas for plant selection and how to arrange and space those plants, look to nearby natural areas that support local native plants, inquire with your local native plant society chapter, and check out my book (if you live west of the Cascades). Plant long-lived trees and shrubs for carbon sequestration and habitat, as well as privacy so that unnecessary fencing may be removed, allowing for a contribution to wildlife corridors that connect. Add associated understory plants, including ground covers that offer the best mulch

Speaking of space, growing perennials for pollinators’ sakes means providing at least several plants of the same species that are planted fairly close to each other so that pollinators can easily find them and so there’s enough of a particular flower’s nectar/pollen to go around. But spacing them evenly, in perfect clumps, isn’t necessary and often looks contrived, and lining them up like veggies in a kitchen garden is even worse, aesthetically speaking. Take a walk in a natural area and you’ll find perennials and other plants with an array of spacing—some close together, some further apart; most mingle with other species that they evolved with. Irregular drifts may occur, as if nature took a paintbrush to create rhythmic splashes. Repetition of plant groupings will result in a natural look and more habitat. Be sure to provide at least a couple of species that flower in unbroken sequence from early spring until fall.


3. Avoid pesticides and use organic methods. It’s imperative to not use pesticides (insecticides, herbicides, fungicides, etc.) and chemical fertilizers to prevent harm to beneficial creatures above and below ground at home and prevent toxins from entering waterways and killing downstream. The Environmental Protection Agency has registered more than 18,000 pesticides for use, and more than 2 billion pounds of pesticides are sold every year in the U.S. Pesticides are pervasive in aquatic and terrestrial habitat throughout the country and threaten the survival and recovery of hundreds of federally listed species. They don’t stay put and can kill non-targeted species, decrease biodiversity within soil, are linked to a decline in nitrogen fixation, mess up the complex balance between predator and prey species in food webs, require fossil fuels, and involve heinously cruel experiments on animals. And, the U.N. tells us that about 200,000 people die each year from pesticide exposure. Chemical fertilizers are also very problematic since they kill soil microbes and pollute groundwater and waterways, leading to dead zones, among other damages.

4. Minimize water runoff and maximize carbon storage. There’s much we can do with the water that enters our landscape, and it doesn’t have to take much effort. It may help to think of our yards as mini-watersheds and ask what we can do to make sure the water that leaves our properties is clean and won’t harm other species.

Rain gardens can collect water — from downspouts or hard surfaces where water accumulates — and slow the flow of water, cleaning it as it slowly soaks into the ground and recharges aquifers. Other elements like bioswales, permeable paving, coniferous trees, and even rain barrels can manage water responsibly in our landscapes, reducing runoff that overwhelms storm drains and pollutes waterways. But it’s the plants themselves (along with soil) that effectively filter water and store carbon. Fully and diversely planted gardens — that include long-lived large trees, shrubs and lower plants — are best at cleaning water, preventing runoff, and sequestering carbon; more so than lawn or beds that are mostly wood chips. 

Halictus ligatus on Erigeron speciosus.

Although keeping your soil covered (with plants or mulch) is a good thing for carbon storage, moisture retention and erosion control, always leave some areas with bare soil (fallen leaves and small amounts of light compost are okay), particularly in areas that face south or east. Here’s why:  70% of native bees (such as this “sweat bee,” Halictus ligatus, shown) nest in the ground (the rest raise their young aboveground in cavities, stems, tunnels or crevices). Using thick layers of wood chips, bark dust, or other such substances prevents them from being able to create their nests and if applied after nests are complete, entombs and kills the developing bees.

Also, if you grow veggies, keep tillage to a minimum, if at all. Tilling soil speeds up the decomposition of organic matter, causes erosion, releases carbon dioxide into the air, exposes weed seeds to light, destroys mycorrhizae hyphae, and generally makes soil less fertile. Unnecessary fertilizer will also release more carbon. 

Erosion concerns? Choose native plants with dense, fibrous root systems to control erosion on slopes. In the Pacific Northwest, depending on your location and conditions, consider Douglas-fir, big-leaf maple, vine maple, Oregon white (Garry) oak, madrone, serviceberry, salal,  kinnikinnick, red-twig dogwood, oceanspray, tall Oregon grape and Cascade Oregon grape, western mock orange, red-flowering currant, snowberry, western sword fern, inside-out flower, and many others.

Bushtit nests require moss, spider silk, and other natural substances.

5. Add natural elements and be lazy. Wild species need secure, dry places to spend the winter, pupate, or seek cover during bad weather, and places to raise their young:  (1) Leave the leaves on soil. (2) Include rotting logs and other dead wood in shady spots to supply the perfect home for certain invertebrates and fungi. (3) Introduce brush piles to provide shelter and maybe even nest sites for some birds. (4) If you’ve dug up rocks from your soil, create smooth rock piles or stone walls without mortar to provide cover for wildlife like amphibians and reptiles, as well as arthropods. Making all these elements as large as possible and placing them in quiet areas works best. (5) If you must “clean up,” don’t do it in fall or winter. Instead, wait until late spring and do as little as possible so that those taking cover won’t be disturbed and so that birds can find building materials for their nests, such as moss, lichen, twigs, spider silk, and dried leaves (see bushtit nest, pictured above). If all this sounds messy, it is, but it’s also easy and exactly that characteristic that supports the greatest garden biodiversity! 

Last but not least, give wildlife a drink. All animals — from birds and dragonflies to frogs and salamanders — need water, so include a gently sloping bird bath or more elaborate water feature like a pond, and perhaps a plate full of watery gravel to help creatures thrive. Although the latter is most important during dry weather, birds need water year round to keep their feathers clean and waterproof. Since many urban streams have been buried, wetlands drained, and drought is upon us, it’s the least we can do.

Golden-crowned kinglet and Townsend' warbler.

© 2021 Eileen M. Stark

Ten New Year’s Resolutions For Your Eco-Garden

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Conjuring up some New Year’s resolutions? Don’t forget about your yard and the ecosystem of which we are a part. Promise to do something positive in your yard this coming year to help dwindling wild species whose habitats have been—and continue to be—ravaged.

You certainly don’t need to replace every plant in your yard or eliminate all of your lawn to give back to nature, although the more the better. And you don’t need to do everything all at once—baby steps are fine! In fact, incremental change is usually best, since wild species using existing plants and other elements might be harmed by a drastic, rapid change. If you don’t have a yard, think about volunteering with an organization that’s working on a restoration project—it can be satisfying and enjoyable.

Here are ten resolutions I recommend to help make your yard more humane and functional in the coming year. Some are very easy, some not quite so much. Choose one, two, or all! They are not listed in any particular order because each one is important.

Add some clean water. Birds, insects, mammals, amphibians—all creatures—need water year round to survive. Even just a shallow bird bath can help, but some maintenance is a good thing: Change the water every few Bird bath robin babydays, give it a good scrubbing every week or two, and keep it out of reach of marauding cats and dogs. Plates or shallow bowls filled with clean pebbles or gravel and water will provide for insects; butterflies will also appreciate mud puddles which they use to obtain moisture and nutrients essential for breeding. Artificial ponds should be shallow on one side and have gradually sloping sides so tiny animals can get out easily. More tips here.

Let natural systems flourish and harmonize by minimizing “clean-ups” and maintenance. Yes, this one lets you work less! Allow fallen leaves to stay on the soil to create cover for overwintering insects like bumblebees and butterflies as well as food for birds, raking or sweeping them only off areas that need to be clear (like sidewalks, driveways, or lawn). Leave dead wood such as snags (dead or dying trees that won’t crash on someone’s head) and “downed wood” —fallen branches, twigs, and bark—which is absolutely essential wildlife habitat that will protect and nurture soil, too. Create brush piles or rock piles to help provide cover and nest sites for birds pilesand other small creatures. Leave seed heads and flower stalks on perennials until spring is well under way to provide food, cover, and habitat. If/when you eventually cut them back, leave them on the ground for a month or longer in case they contain native bee larvae or other overwintering insects waiting for the chance to live out their lives.

Get rid of invasive plants that compete with natives. Depending on the plant species, this can be an easy job or one likely to give you headaches, backaches, and an urge to scream. It can take a few days or a few years. But once your task is accomplished, I guarantee that you will feel an extreme sense of satisfaction. And there will be more room to plant lovely, functional plants! If you have several invasive species in your yard, determine which may be the most invasive and start with that. Nonnatives that produce berries, like English holly trees, are particularly problematic because they spread into nearby natural areas by birds, but also via vegetative reproduction. English ivy also produces berry-like fruit and spreads by rooting on the soil surface and on tree trunks—at the very least, periodically cut it back at the base of trunks to prevent it from harming trees. There are numerous introduced plants that push out native species, so check with city, county, and/or state agencies to find lists and descriptions of invasive plants in your area; the USDA also offers information. My book offers some tips for removing invasive plants, as does Green Seattle Partnership and this post.

Remove lawn. Lawn for the sake of lawn is not beneficial and is awfully wasteful. When deciding which part(s) of your lawn will receive walking papers, start by choosing areas that you never or rarely use. Often this is the front yard. If you’re not ready to go all the way and remove a large area of turf, consider at least removing lawn under trees and in areas that are difficult to mow, such as slopes. Lawn can also be minimized by enlarging existing beds and adding ecologically beneficial native plants. The gentlest way to remove lawn is to simply cover it with about 6 sheets of overlapping newspaper (or cardboard) on a non-IMG_0403 sRGBwindy day. Dampen it, poke a some small holes, then top it with 4 or 5 inches of weed-free compost (leaf compost is good) and fallen leaves over that. Leave it to decompose for at least several months (until grass roots have died) before planting. Removing lawn via a sod cutter or spade can damage tree/shrub roots.

Grow native plants that are indigenous to your area. For this I suggest you consult a regional native gardening book like my book (if you live in the Pacific Northwest, west of the Cascades). Choose species (preferably “true species,” not cultivars) that are native to your area and that will flourish in your site’s soil, light, and moisture conditions. Grow them with other members the same plant community to provide the most benefit.

Provide for all life stages of pollinators. Many pollinating insects, including native bees and butterflies, will have gone through several stages by the time they reach adulthood and their needs differ greatly. So, in addition to providing water and growing groups of sequentially-flowering plants (preferably native to your area) that supply pollen and nectar from early spring through fall, provide the “host plants” needed for egg laying and for the feeding of larvae (in the case of butterflies and moths: caterpillars). For insects that undergo a complete metamorphosis, protect habitat for pupa (chrysalis). The latter mainly involves simply leaving fallen leaves and other organic matter on the soil, delaying any pruning of host plants until late spring, and not using leaf blowers, which eliminate the habitat of creatures needing a place to wait out the winter, such as chrysalis held in place on a twig by a fragile silken thread.

Don’t use pesticides or poisons. Synthetic pesticides should be avoided at all costs, but even so-called organic controls can be deadly and indiscriminate, especially if used improperly. If a pest if causing enough damage in your Aphid eaterkitchen garden to warrant a control, consider hand removal, barriers and screens, companion plants, or simply sprays of water from the hose. Allow a natural balance by welcoming natural pest control such as birds (see bushtit devouring aphids, right) and predatory insects.

Protect birds from reflective glass. Up to a billion birds are killed or injured by colliding with buildings in North America each year. Though skyscrapers kill countless birds, large structures four stories or less in rural locales are responsible for the most bird deaths, according to a 2017 study. Many of those strikes can be prevented and here are some ways to help.

Keep Kitty indoors. Domesticated cats kill millions of birds each year, but it’s not their fault they’re outside. Whenever possible, keep your little predators indoors for their safety as well to protect little wild creatures. To prevent boredom and health issues: Add levels, especially around windows, widen windowsills with tables of appropriate height, or add window boxes. If you’re more ambitious, build a catio! They come in all sizes, shapes and price ranges and provide kitty with a safe outdoor experience.      

Turn on the dark. Look out your windows at night and chances are—if you live in an urban area—you won’t see the twinkle-twinkle of little stars because light pollution (any adverse effect of artificial light) is making the night sky glow brighter each year. Its most obvious effects are on migratory songbirds lured into cities where they collide with unnecessarily illuminated buildings, killing more than 100 million of them each year in North America. But lit up low-rise structures in rural locales also distract and have been found to pose greater danger than similarly-sized urban buildings, with what researchers call “the large scale beacon effect.” And for nocturnal animals, artificial light may be the most extreme change forced upon them. You can help by minimizing artificial lighting migration seasons, and anytime to prevent moths from exhausting themselves to death, to keep bats in the dark, and diurnal animals asleep. Choose fixtures that shine light downwards, not to the side or upwards, and use motion-sensors so that lights go on only when necessary. If you worry about crime, studies show that outdoor lighting does not decrease crime and may even exacerbate it; most residential crime occurs during daylight hours. In addition, cover windows with shades or draperies at night to cut down on light escaping your house. More info.


© 2017 Eileen M. Stark

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