All posts by Toni Genberg

Death by Urban Landscaping: How popular landscape plants are destroying local forests

by Beverley Rivera.

As the weather warms, Northern Virginia appears to come alive almost overnight, trees leaf out and unique wildflowers blossom beneath the awakening canopy; but this greening of everything around us actually belies a chilling outlook: much of the striking new foliage is not supposed to be here. Plants that are not native to America are rapidly outcompeting local forest growth for resources: growing space, sunlight, water. In many areas, not only are the invasive plants winning the battle for these resources, they are annihilating the local competition.

Chinese wisteria (Wisteria sinensis) can displace native vegetation and kill trees and shrubs by girdling them. Photo by Matt jones/NatureServe/cc.

Chinese wisteria (Wisteria sinensis) can displace native vegetation and kill trees and shrubs by girdling them. Photo by Matt Jones/NatureServe/cc.

And it’s a problem without a solution because many of the plants that are steadily destroying Virginia’s forests are spreading from people’s gardens and from landscaping at shopping centers and businesses. There are breathtaking areas in Northern Virginia where invasive vines so thick that they require a saw to hack through are suffocating native trees that withstood Civil War battles. Homeowners and landscapers plant these vines in urban settings, the seeds get into the forest via birds, and the non-native plants quickly take over, entangling, suffocating, stunting and displacing everything natural. Invasives such as Chinese wisteria send out vast networks of thick vines that spread above and beneath the ground, quickly engulfing massive areas of natural forest.

Another frightening prospect is that in the normal cycle of things, young trees which are just now getting established would, hundreds of years from now, replace the massive canopy trees as they end their life cycles. If left untainted, the forest rejuvenates itself as it has for thousands of years. But with invasive plants taking over, the young growth that is destined to be our forest of the future is being entangled, smothered and displaced by invasive plants. Adding to the problem is overbrowsing by deer. Deer won’t eat many of the invasive plants, and the natural predators that once kept deer numbers in check are no longer roaming the east.

In fact, the Fairfax County Park Authority’s Invasive ID and Control booklet looks more like a guide to urban landscaping in Northern Virginia.

Equally destructive to our new forest growth are Japanese honeysuckle and English ivy. But these plants are ubiquitous in local landscaping, meaning that even if an army of volunteers managed to remove all the invasives from an area, the seeds from urban landscaping would quickly reinfest the forest. Invasive butterfly bush is another staple in Northern Virginian landscaping, as are Japanese barberry, Pachysandra, Miscanthus, Bradford pear, privet, Norway maple, burning bush; the lists of plants that become invasive once they leave the suburban landscape is ongoing. In fact, the Fairfax County Park Authority’s Invasive ID and Control booklet looks more like a guide to urban landscaping in Northern Virginia.

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English ivy before and after: for sale at a local garden center and its escape into the wild.

This prevalence of invasive plants in our gardens invites the question: if invasive plants are destroying Virginia’s natural areas, why are many of these plants still widely available for sale? To some extent the blame for the degraded state of our natural areas must lie with the stores that are supplying invasive plants. But I also think that at some point, we as homeowners must take our share of the responsibility. We need to think about the consequences of our actions on the future of Virginia’s forests, or else our forests are just not going to be around for future generations.

Introduced and invasive plants like butterfly bush and Japanese barberry adorn many residential properties.

Introduced and invasive plants like butterfly bush and Japanese barberry adorn many residential properties.

There’s a native plant for every gardening situation

Virginia has such an abundance of plant diversity that there is no excuse for planting invasives. For every invasive plant there is an equally attractive native alternative. And the added benefit of planting local plants is that once established in the right conditions, they become very low maintenance; native plants have been here much longer than watering cans and fertilizers have. Gorgeous alternatives, for example, to the invasive butterfly bush are our fall-blooming goldenrods (Solidago spp.) and asters (Symphyotrichum spp.) which are even more fabulous when planted together. They attract more pollinators than the much-loved non-native. For an attractive evergreen ground cover alternative to English ivy, there’s golden ragwort (Packera aurea). For every plant that you think you can’t live without, there is a selection of native alternatives; there’s even a native wisteria, American wisteria (Wisteria frutescens).

Golden ragwort (Packera aurea) is a wonderful alternative to English ivy. And it doesn't kill trees.

Sunny golden ragwort (Packera aurea) is a wonderful alternative to English ivy.

But don’t expect the large local garden centers, or the plant sales that crop up in shopping center parking lots to stock an abundance of native plants – because they don’t. They might stock a few cultivars, which are plants that have been bred to enhance particular traits such as vibrant color or hardiness, so they may be labelled “native” but they contain modifications. Another caveat about native plants is obtaining plants that belong in this region, they’re referred to as “local ecotypes.” Just because a plant is “native” to Northern America – which is vast in its geography and hence its plant diversity – doesn’t mean that it belongs in Virginia, or that it couldn’t potentially become invasive if introduced to this region. Our local ecotypes also have evolved to form special relationships with our indigenous animals. Some native bees, for example, pollinate only one species of plants, which required millions of years of evolution.

Northern Virginia resources abound!

Fortunately, there are some excellent resources available for planting what is local. The Plant NoVA Natives website has recommendations of what to plant specific to Northern Virginia, and their online guide even covers recommendations for problem planting areas. The Virginia Native Plant Society also has a wealth of resources including a list of alternatives for English ivy. One excellent source for buying local ecotypes is Earth Sangha’s Wild Plant Nursery.

One last word of caution when buying plants at big box stores or mainstream garden supply shops is that there is much talk about whether the presence of certain pesticides known as neonicotinoids are contributing to the alarming decline of pollinators. Shop wisely and with an eye to the future.

Virginia has a wealth of gorgeous natural areas that are being devastated by the invasive plants that we are cultivating in our own backyard. Help to preserve the fascinating diversity of this region’s native plants by growing what belongs here.

 

Nectar Sources for Large-Winged Butterflies of the Mid-Atlantic 

Ooooo, a monarch! It takes an erratic path across the garden, bright orange wings gliding and flapping, drifting and fluttering. It floats down and lights on a stalk of common milkweed and after a momentary pause, the dark abdomen curls and a single egg is precisely laid underneath a small, tender leaf. She repeats the process twice more. The mother butterfly discovers another stand of young shoots on the opposite side of the garden and continues her delicate dance. An egg here. Flutter flutter. Another egg gently placed there. Three years have quickly passed since I planted tiny milkweed plants and they now command ample portions of this wildlife habitat, creating a welcoming haven for monarchs—adults and larvae alike. It’s mid-summer, with clear skies and still air; the perfect conditions for butterfly spying.

A monarch caterpillar munches common milkweed (Asclepias syriaca). Plant this if you want to make more monarch butterflies.

Common milkweed (Asclepias syriaca) and monarch caterpillars go hand-in-hand.

Scrutinizing the plants that make up this front yard garden, I stand in the warming sun and consider whether there’ll be sufficient nectar for any new monarchs when nearly a month from now the miraculous four stage metamorphosis, from egg to larva to pupa to butterfly, is complete. The smaller butterflies such as skippers and fritillaries frequent a wide variety of flowers but the large-winged beauties, I’ve noticed, are slightly more discerning. What flowers do they want? This question sent me on the most colorful of journeys…

Are you gonna eat that?

Butterflies are the magical creatures gracefully flitting through princess tales and are undeniably the most beloved of all our insects. Although not the most efficient pollinators when compared to native bees and flies, butterflies nonetheless play an important ecological role.

A monarch collecting nectar on butterflyweed (Asclepias tuberosa) with proboscis extended.

A monarch collecting nectar on butterflyweed (Asclepias tuberosa) with proboscis extended.

Most butterflies live on nectar from flowers and some also receive nourishment from pollen, tree sap, rotting fruit, carrion, dung, aphid honeydew and minerals found in wet sand or dirt. They have a proboscis, a long complex food canal that is straw-like and coiled when not in use. Proboscises come in different lengths and can dictate which flower a butterfly may drink from.

What else might make one flower more alluring to a particular butterfly than the next? Scent and color can be enticing components. Some researchers also identified butterfly morphology as a factor; they found that species with a “high wing load” generally preferred clustered or nectar-rich flowers. This would explain all the swallowtails on Joe Pye Weed!

You may be tempted to plant butterfly bush (Buddleja spp. and cultivars) because you notice your neighbor’s attracts butterflies late in the growing season. Please resist the urge to do so! Butterfly bush is an introduced plant from Asia that does not support local food webs. It’s also an invasive shrub that outcompetes native flora for resources and negatively impacts all our wildlife. Some prudent states have taken steps to ban the sale of butterfly bush.

FROM EGG TO ADULT: Support a butterfly’s full life cycle

While wildflower nectar is a necessary habitat component for butterflies, other plant life such as native grasses, vines, shrubs and trees are equally crucial for food and shelter. A landscape with tons of plant diversity will help not only butterflies but also our other wild critters— great and small and every life in between.

The spicebush swallowtail caterpillar relaxing on one of its host plants, spicebush (Lindera benzoin).

A spicebush swallowtail caterpillar lounging on one of its host plants, spicebush (Lindera benzoin).

Let’s grow butterflies! It’s easy to do: just add the plant that their larvae will eat. These specific plants that caterpillars need for food are called host plants. Monarchs, as we know, require milkweed or Asclepias species to reproduce. Host plants are not optional for caterpillars and some, like those of the zebra swallowtail, the pipevine swallowtail and the monarch, have only one genus of plant that they can eat. What Do Caterpillars Eat by the Washington Area Butterfly Club lists some common butterflies and their typical host plants.

Did you know that butterflies need water, too? You can provide essential moisture and minerals by filling a shallow dish with damp sand or mud. It’s a bit of maintenance but well worth it if you spy even a tiny skipper taking a drink, as I have. And don’t forget to leave the leaf litter! There are butterfly and moth species that overwinter as egg, larva or pupa in the blanket of fallen leaves and debris. Let’s not be tossing out the butterflies we’re trying to encourage.

FLOWER POWER!

Here the spotlight is thrown on a handful of sun-loving native herbaceous plants that large–winged butterflies such as the monarch and swallowtails have been observed to frequent. The bloom times are varied, beginning in early summer and ending in fall, when late-season nectar is crucial for migrating butterflies. These lovely plants will naturally support smaller butterflies, native bees and insects, as well as other animals throughout the food web. If the plant is a known Lepidoptera (butterfly and moth) caterpillar host, that information from Doug Tallamy’s research is included as well. Remember to choose native plant species that occur naturally in your area to keep wild areas functioning. Happy butterfly watching!

I do not include plant hardiness zone information because if you’re planting regionally native plants, as I hope you are, that information is unnecessary.

Common milkweed (Asclepias syriaca) with eastern tiger swallowtail and a few other friends.

Common milkweed (Asclepias syriaca) with an eastern tiger swallowtail and a few other friends, including a silver-spotted skipper. Note the huge leaves designed for hungry monarch caterpillars.

Common Milkweed (Asclepias syriaca)
Height: 3 – 5 ft, up to 8 ft
Bloom time: June – August
Sun: Full
Moisture: Medium to Low
Soil: Medium to fine sandy, clay, well-drained loamy, rocky calcareous; pH moderate
Natural habitat: Fields, pastures, roadsides
Notes: The large leaves of this Asclepias species are sought by monarchs looking to lay their eggs.
USDA Forest Service: “Common milkweed is Nature’s mega food market for insects. Over 450 insects are known to feed on some portion of the plant.”
Some gardeners consider A. syriaca to be a thug. Any shoots that pop up where they’re not wanted are easy to pull or cut.
Milkweeds are host to 12 species of native caterpillars including the monarch butterfly.
Other optionsSwamp milkweed (Asclepias incarnata) is a moisture-loving species.
More information: USDA Forest Service Plant of the Week: Asclepias syriaca

A zebra swallowtail on butterfly weed (Asclepias tuberosa)

Out in the wild: a zebra swallowtail on butterfly weed (Asclepias tuberosa). Zebra swallowtails have only one host plant: paw paw (Asimina triloba).


Butterfly Weed (Asclepias tuberosa)
Height: 1 – 3 ft
Bloom time: May – August
Sun: Full
Moisture: Low
Soil: Rocky, poor, well-drained; pH moderate
Natural habitat: Dry open woodlands, fields, roadsides
Notes: Butterfly weed has grown successfully in well-drained clay in my Northern Virginia garden.
It’s best to give thought to where it’s planted because the large taproot doesn’t like to be transplanted once established.
Deer don’t typically browse Asclepias foliage but they may gobble up the tender seed pods, milkweed bugs and all.
Host to 12 native butterfly and moth species, including the monarch.
More information: Virginia Native Plant Society 1992 Wildflower of the Year: Asclepias tuberosa

Eutrochium spp. covered in swallowtails. Tiger swallowtails have many host plants including black cherry (Prunus spp.), willow (Salix spp.) and basswood (Tilia spp.) trees. Photo by miss-myers/flickr/cc. 


Hollow Joe Pye Weed (Eutrochium fistulosum)
Height: 5 – 7 ft, can grow taller
Bloom time: May – August
Sun: Full, Part, Shade
Moisture: Medium
Soil: Rich
Natural habitat: Floodplain forests, alluvial and seepage swamps, riverbanks, wet meadows, ditches
Notes: The frothy flowers are some of the best for attracting pollinators.
Song birds eat the ripened seeds.
Eutrochium spp. are host to 42 species of native caterpillars.
Other options: Sweet Joe Pye Weed (Eutrochium purpureum), Spotted Joe Pye Weed (Eutrochium maculatum), Three-nerved Joe Pye Weed (Eutrochium dubium)
More information: Maryland Native Plant Society Wildflowers in Focus: Joe Pye Weed

Wild bergamot (Monarda fistulosa) and eastern tiger swallowtails.

Wild bergamot (Monarda fistulosa) and eastern tiger swallowtails in a wild meadow.

 


Wild Bergamot (Monarda fistulosa)
Height: 1 –  5 ft
Bloom time: June – August
Sun: Full, Part
Moisture: Medium, Medium-Low
Soil: Adaptable, rocky, rich, sand, clay
Natural habitat: Mesic to dry upland forests, rocky woodlands, clearings, forest edges, meadows, fields, roadsides
Notes: Bumblebees, hummingbird moths and hummingbirds also frequent wild bergamot.
It colonizes by rhizomes but it’s easy to control.
Monarda spp. are host to seven species of native caterpillars.
Other options: the red-flowered Bee Balm (Monarda didyma)
More information: Virginia Native Plant Society 1993 Wildflower of the Year: Wild Bergamot

A monarch on New England aster (Symphyotrichum novae-angliae). Photo by David Marvin/flickr/cc.

A monarch on New England aster (Symphyotrichum novae-angliae). Photo by David Marvin/flickr/cc.


New England Aster (Symphyotrichum novae-angliae)
Height: 1 – 6 ft and taller
Bloom time: August – October
Sun: Full, Part
Moisture: Medium
Soil: Adaptable, rich, sand, loam, clay
Natural habitat: Moist, open woods, wet meadows, stream banks, alluvial fields
Notes: New England aster has a long bloom period and is enjoyed by many insects.
It can get leggy in a garden setting; some gardeners continually pinch it back before July to control its height, but note that the blooms may open later.
New England aster reseeds abundantly!
Asters are known to host 112 species of native caterpillars.
Other options: Aromatic Aster (Symphyotrichum oblongifolium), New York Aster (Symphyotrichum novi-belgii)

Goldenrod (Solidago spp.) at left and grass-leaved goldenrod (Euthamia graminifolia) on right. Photos by Putneypics/flickr/cc & Lisa Bright/Earth Sangha.

 


Showy Goldenrod (Solidago speciosa)
Height:  1 – 6 ft
Bloom time:  August – October
Sun: Full
Moisture: Medium, Low
Soil: Adaptable, loam, clay
Natural habitat: Dry, open forests, woodlands, clearings, roadbanks
Notes: Goldenrods are for pollinators; hummingbirds have also been observed sipping nectar.
Plant goldenrod with purple asters for a fabulous fall display.
Solidago spp. are host to 115 species of native caterpillars. Euthamia spp. host five.
Other options: There are many species of goldenrod adapted to varying habitats. Here are some sun-loving options: Early Goldenrod (Solidago juncea), Sweet Goldenrod (Solidago odora), Tall Goldenrod (Solidago altissima), Rough-stemmed Goldenrod (Solidago rugosa), Gray Goldenrod (Solidago nemoralis), Grass-leaved Goldenrod (Euthamia graminifolia)

Hoary mountain mint (Pycnanthemum incanum) growing in a natural area. The swallowtails are delighted! Photo by Lisa Bright/Earth Sangha.


Hoary Mountain-Mint (Pycnanthemum incanum)
Height: 2 – 6 ft
Bloom time: June – July
Sun: Sun, Part
Moisture: Medium, Dry
Soil: Loam, sand, rocky, well-drained; pH acid-based
Natural habitat: Forests, forest borders, rocky woodlands, clearings, roadsides
Notes: Deer resistant like most plants in the mint family, (Lamiaceae).
Pycnanthemums are host to three species of butterflies and moths.
Other options: There are many Pycnanthemum species; Clustered Mountain-Mint (Pycnanthemum muticum) is another fine choice for luring swarms of pollinators.

 

Mistflower (Conoclinium coelestinum) blooms just when the insects need it.

Mistflower (Conoclinium coelestinum) blooms just when our insects need it.


Mistflower (Conoclinium coelestinum)
Height: 1 – 2 ft
Bloom time: August – September
Sun: Sun, Part
Moisture: High, Medium
Soil: Moist loam, sand, clay
Natural habitat: Floodplain forests, stream banks, swamps, moist to wet meadows, clearings
Notes: Spreads quickly by rhizomes and self-sowing in optimum conditions; easily lifted to share with friends and neighbors.
Skippers and small pollinators enjoy mistflower as much as the larger butterflies.
Usually deer resistant.
Although not a known Lepidoptera host plant, mistflower is nonetheless an important habitat plant.

New York ironweed (Vernonia noveboracensis) and monarch. Photo courtesy Chesapeake Conservation Landscaping Council.

Pretty New York ironweed (Vernonia noveboracensis) and monarch. Photo courtesy Chesapeake Conservation Landscaping Council.

 

 


New York Ironweed (Vernonia noveboracensis)
Height: 3 – 8 ft
Bloom time: July – September
Sun: Full, Part
Moisture: High, Medium
Soil: Rich, adaptable; pH acid to neutral
Natural habitat: Floodplain forests, alluvial swamps, riverbanks, wet meadows, low fields, tidal swamps
Notes: Seedheads attract birds such as goldfinches.
Vernonia spp. are host to 19 species of Lepidoptera.
Other options: Broad-leaf Ironweed (Vernonia glauca); this species requires less moisture than New York ironweed.
More information: Virginia Native Plant Society 1995 Wildflower of the Year: New York Ironweed

Wingstem (Verbesina alternifolia). Photo by Vicky DeLoach/flickr/cc.

Wingstem (Verbesina alternifolia). Photo by Vicky DeLoach/flickr/cc.

 

 


Wingstem (Verbesina alternifolia)
Height: 3 – 10 ft
Bloom time: August – October
Sun: Full, Part
Moisture: High, Medium
Soil: Rich
Natural habitat: Floodplain forests, alluvial swamps, riverbanks, low meadows, fields
Notes: Wingstem is a prolific self-seeder.
The rough leaves help make this plant deer resistant.
Sixteen native caterpillar species are hosted on Verbesina.

 

 

 

Pasture thistle (Cirsium pumilum) on the left and field thistle (Cirsium discolor), a taller-growing species, on the right. C. discolor photo by Lisa Bright/Earth Sangha.

 


Pasture Thistle (Cirsium pumilum)
Height: 1 – 3 ft
Bloom time: June – August
Sun: Full
Moisture: Medium, Low
Soil: Poor, clay, well-drained
Natural habitat: Clearings, meadows, fields
Notes: Pasture thistle is an uncommon garden plant that’s fun to grow regardless of the pokey spines.
It’s a shorter species that may be better suited for garden habitats.
Bumble bees enjoy the pollen of the large 2-3 inch flower heads.
Many of the commonly seen thistles like bull thistle and Canada thistle are introduced and considered invasive.
Host to 27 Lepidoptera species.
Other options: There are many native thistles; Field Thistle (Circium discolor) is a tall species, shown on the right side of photo.

 

Dense blazing star (Liatris spicata) is a wonderful addition to the moist garden. Photo by Debbie Roos.


Dense Blazing Star (Liatris spicata)
Height: 3 – 6 ft
Bloom time: July – September
Sun: Full
Moisture: High, Medium
Soil: Rich, well-drained
Natural habitat: Moist to wet meadows, clearings, riverside prairies, seeps
Notes: Stunning when massed; the tall spikes add vertical structure to a garden.
Known to attract hummingbirds.
Host to four species of native caterpillars.
Other options: There are many! Scaly Blazing Star (Liatris squarrosa), Grass-leaf Blazing Star (Liatris pilosa), Eastern Blazing Star (Liatris scariosa), Rough Blazing Star (Liatris aspera)

 

 

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Cup plant (Silphium perfoliatum) and a worn but beautiful monarch. Photo by JanetandPhil/flickr/cc.

 


Cup Plant (Silphium perfoliatum)
Height: 3 – 8 ft
Bloom time: July – September
Sun: Full
Moisture: High, Medium
Soil: Rich, adaptable
Natural Habitat: Floodplain forests, alluvial clearings, low meadows
Notes: The large clasping leaves form ‘cups’ that collect water.
A prolific reproducer.
Birds enjoy the seeds, and the thick hollow stems make excellent nests for native bees.
Host to four species of Lepidoptera.


 

 

 

Shrub bonus!

The following two woody plants are nearly always recommended as excellent sources of butterfly nectar.

Spicebush butterfly on a spicebush flower ball (Cephalanthus occidentalis). Photo by John Flannery/flickr/cc.

A spicebush butterfly on a buttonbush flower sphere (Cephalanthus occidentalis). The spicebush caterpillar requires the leaves of its host plants, spicebush (Lindera benzoin) and sassafras (Sassafras albidum). Photo by John Flannery/flickr/cc.

Buttonbush (Cephalanthus occidentalis)
Height: 6 – 12 ft and up
Bloom time: June – August
Sun: Full, Part
Moisture: High, Medium
Soil: Poor, sand, clay
Natural Habitat: Marshes, tidal shrublands, open swamps, floodplain pools, depression ponds, usually in seasonally or semi-permanently flooded habitats
Notes: Typically grown as a small tree; the long-lasting flowers attract a multitude of insects.
Nineteen species of Lepidoptera are hosted on Cephalanthus.
More information: Fairfax County Public Schools, Virginia: Buttonbush

 

 

 


Sweet pepperbush (Clethra alnifolia) has fragrant wands of flowers that attract oodles of pollinators. Photo by Wendy Cutler/flickr/cc.

Sweet pepperbush (Clethra alnifolia) has fragrant wands of flowers that attract oodles of pollinators. Photo by Wendy Cutler/flickr/cc.

Sweet Pepperbush (Clethra alnifolia)
Height: 3 – 6 ft, up to 12 ft
Bloom time: July – August
Sun: Part, Shade
Moisture: High, Medium
Soil: Adaptable, sand, clay; pH acid
Natural Habitat: Mesic to rather dry, acidic upland forests, wet flatwoods, seepage swamps, and bogs
Notes: The leaves emerge late in spring; lovely yellow fall color.
Clethra hosts 9 species of native butterflies and moths.
More information: Virginia Native Plant Society 2015 Wildflower of the Year: Sweet Pepperbush

  

 

 

Asters and goldenrod are excellent choices for the habitat garden.

Asters and goldenrod are excellent choices for the habitat garden.

Resources & Information:

Digital Atlas of the Virginia Flora

Lady Bird Johnson Wildflower Center

Albemarle County, Virginia: Piedmont Native Plants

Plant NOVA Natives

The Xerces Society: Mid-Atlantic Region Pollinator Plants

National Wildlife Foundation: Attracting Butterflies

Virginia Native Plant Society: Wildflowers for Butterfly Gardens

Maryland Native Plant Society: Using Native Plants to Attract Butterflies

Fairfax County: Using Native Plants to Attract Butterflies, Moths, Bees and Other Pollinators in the Washington DC Area

Butterfly Fun Facts

Northern Woods: The Butterflies of Winter

Research: Factors influencing the degree of generalization in flower use by Mediterranean butterflies

Researchgate: Butterfly nectaring flowers: Butterfly morphology and flower form

 

Rat Poison Kills A Hell of a Lot More Than Just Rodents

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The dead mouse.

I inspected the tiny creature closely. It must have died recently, its brown and white furred body still soft and supple. Was it an outdoor cat that killed it? It certainly could have been. Free roaming cats have left quite a number of birds and small mammals for me over the years. But there didn’t appear to be any signs of trauma; no puncture wound and no blood. Hmmm. I dismissed the thought that this animal was poisoned—surely my immediate neighbors know that rat bait is a wretched solution? I left the mouse where it was, figuring it could be food for some other critter. Unfortunately, this was a mistake.

The Big Lie

It turns out a neighbor did have a rodent bait box on his property. He explained that he had mice entering his house and insects that needed controlling which prompted him to hire a pest control company. When I mentioned the effects of poisoned rodents on our foxes and other wildlife, my neighbor, who equally enjoys our wildlife, insisted the bait used wasn’t poisonous—the exterminator told him so. Hmmm?! Evidently some pesticide companies tell customers only what they want to hear, no matter how big the lie.

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A rodent bait box stationed outside a nearby Chipotle. Little thought is given to the other animals that live in this mixed-use development.

Second-Generation Killers cause Secondary Victims

Today’s most widely used rat poisons are second-generation anticoagulants: highly toxic not only to the rodents that directly consume the bait but also to the non-target animals that eat the contaminated rodents.

Although the EPA has prohibited the sale of products containing brodifacoum, bromadiolone, difenacoum and difethialone directly to consumers, pest control companies and farmers are still allowed to use these second-gen anticoagulant rodenticides.

Like the first-generation of anticoagulants that preceded them, the “superwarfarins” prevent blood from clotting, induce internal bleeding and inflict a prolonged, painful death. However the newer poisons are many times more potent. “Second-generation anticoagulants,” the EPA explains, “are more likely than first-generation anticoagulants to be able to kill after a single night’s feeding. These compounds kill over a similar course of time but tend to remain in animal tissues longer than do first-generation ones.” This means that by the time the rodents die—five to seven days after consuming the bait—they can have up to 30-40 times the lethal dose in their bodies. Meanwhile, they stumble about and are easy prey for predators and pets.

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How many poisoned meals have our resident hawks had?

Collateral poisonings of carnivores and omnivores alike are widespread wherever bait boxes are being deployed. The affected wildlife are more likely to get hit by moving vehicles, crash into structures or be killed by other animals. These non-target animals are also more susceptible to disease and vermin. In California, most coyotes, bobcats and cougars that die from mange—a skin disease caused by parasitic mites—also test positive for rodenticide exposure.

Some Fast Facts:

  • Rodenticides are indiscriminate killers that attract and kill all kinds of animals, not just rats and mice.
  • Second-generation anticoagulants are persistent and bioaccumulative; they remain in the victim’s bloodstream and accumulate in the liver.
  • Non-target predators like foxes, coyotes, owls and hawks, and scavengers such as vultures, raccoons and opossums, suffer lethal and sub-lethal poisoning when they feed on poisoned rodents.
  • Where second-generation anticoagulants are used, entire food webs are contaminated.
  • By killing off the predators that would otherwise control rodents, anticoagulants actually generate rodent infestations.
  • In one Canadian study of dead raptors, nearly 100 percent of owls had at least one anticoagulant rodenticide in their livers.
  • The Centers For Disease Control receive about 15,000 calls per year from parents whose children have eaten rodenticides.

  • Cats and dogs are also harmed from eating poisoned rodents.

What Can You Do?

Residents, homeowners associations and business owners have the power to prevent rodent infestations and not resort to using rodenticides.

  • Remove trash and food that attracts rodents to your property. This includes pet food, birdseed waste and compost piles.
  • Plug holes and cracks leading to the interior of homes and other structures.
  • Keep shrubs and trees trimmed and the foundation of buildings free of wood and junk piles that provide shelter to small critters.
  • Remove invasive English ivy—it’s known to harbor rats. Replace it with native plants that support beneficial wildlife.
  • Seek poison-free solutions to help reduce the market for poison.

Last-Ditch Options

  • If you need to kill, electrocuting traps appear to be the most humane.
  • Snap traps don’t always kill instantly. If you plan to use them, never set them outside. Birds and other wildlife that help control rodents can be seriously injured. Check and empty the traps regularly.
  • Do not use glue or sticky traps because they are cruel and can also catch other small mammals, birds and even reptiles and salamanders.
  • And then there’s the “better mouse trap.” From Ted Williams’ article Poisons Used to Kill Rodents Have Safer Alternatives: “You take a metal rod, run it through holes drilled in the center of both lids of an emptied tin soup can so the can becomes a spinning drum. Fasten both ends of the rod to the top of a plastic bucket via drilled holes. Coat the can with peanut butter, and fill the bucket with water and a shot of liquid soap (to break the surface tension and thus facilitate quicker, more humane drowning). Mice and rats jump onto the can, and it spins them into the water. The first time I deployed the device in my New Hampshire fishing camp, it killed 37 mice between Labor Day and Thanksgiving.” To avoid killing other small mammals, set this device indoors.
RATS-Poster-Jackie-500x

One of RaptorsAreTheSolution.org’s many educational materials.

If you are considering a trap and release, please read Nancy Lawson’s article Stranger in a Strange Land before you do.

For more information:

Scientific American—Blood Thinning Rat Poison is Killing Birds Too

Raptors are the SolutionAlternatives & Tips

Safe Rodent Control—Risks for Wildlife

BIRC (Bio-Integral Resource Center)—Protecting Raptors From Rodenticides

Audubon—Poisons Used to Kill Rodents Have Safer Alternatives 

SPCA—Coyotes and Rodenticide Poisoning

Environmental Protection Agency—Controlling Rodents and Regulating Rodenticides

Did the Pachysandra Kill the Hickory Tree?

Me and the killer Pachysandra.

Me, my hickory and the Japanese spurge in hand.

by Joan Gottlieb.

In my yard there is a large bed of Japanese spurge (Pachysandra terminalis), a plant widely used in landscaping. This hardy evergreen ground cover spreads by rhizomes to create what some proponents consider a “dependable green carpet.” If allowed to escape, it will cover a large area with a Pachysandra monoculture. Since my bed is contained, I wasn’t worried about the spreading. Although a bed of native plants would surely provide better habitat, the Pachysandra seemed a relatively benign bit of greenery. Its removal was not my priority. Until recently…

Within this bed, surrounded by the Pachysandra, there’s a mature hickory tree that didn’t leaf out fully last summer. Each branch showed signs of stress with small, sparse leaves. Many branches had areas with no leaves at all. I consulted an arborist who had no explanation for the decline but suggested a fertilizer treatment be applied in the spring. Hmmm.

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A dense mat of roots.

Unpleasant Surprise

Over the winter, I began the long ignored task of Pachysandra removal, partly to allow inspection of the tree base, but also because it really was the right thing to do. The Japanese spurge was very easy to pull by hand from the soft, humus-rich soil. But what my pulling unveiled was a deep network of tangled roots that had buried the hickory’s root flare and smothered it with layers of moist debris.

Removing the evergreen Japanese spurge revealed rotting bark.

Rotting bark revealed.

Sadly, the entire circumference of the tree’s base was now spongy decaying bark – bark that would otherwise protect the tree itself.

I do not yet know if the tree can be saved. Did my negligence allow the Pachysandra to kill the hickory tree?

Information about the homicide suspect can be found through Pennsylvania DCNR: Invasive Plants in Pennsylvania.

A discussion of its use in landscaping is here, but I do not advise using Pachysandra terminalis at all.

How to Feed a Hummingbird Part II: Flowers & Nectar

This is Part II in a two-part series.

Photo by Jason Means/flickr/CC.

Cardinal flower (Lobelia cardinalis) pollination. Photo by Jason Means/flickr/CC.

Part I of How to Feed a Hummingbird: Insects & Protein revealed that 80 percent of a hummingbird’s diet is comprised of insects and spiders. Eighty percent! Knowing how crucial those often maligned arthropods are to our ruby-throated hummingbirds will hopefully inspire you to embrace the bugs and add a variety of native plants to your garden.

If you are at all curious about hummingbirds you’re probably assuming the missing 20 percent or so of their diet comes from nectar — and you’d be right. Let’s explore the flowering native plants our high-metabolic friends count on for a full-on sugar rush.

THE BIG THREE Wildflower Nectar Sources

Just like bees and butterflies and other pollinators, ruby-throated hummingbirds rely on a constant source of nectar from early spring into fall. Nectar is found in flowers adapted for hummingbirds: long and tubular with a typically pendulous and perchless form. These floral traits are perfect for long beaked, hovering hummers but not convenient for insects that cannot easily reach the hidden nectar. Another evolutionary adaption is the color red. Red is not seen by bees however it quickly signals keen-eyed migrating hummingbirds that a sugary treat awaits.

What combination of plants provides an overlapping progression of blooms? Potowmack Chapter President of the Virginia Native Plant Society, Alan Ford, names the following BIG THREE flowering natives as attracting and supporting our ruby-throats throughout their days in the Mid-Atlantic: Continue reading

How to Feed a Hummingbird Part I: Insects & Protein

Photo by Tibor Nagy, Flickr cc.

A male ruby-throated hummingbird (Archilochus colubris). Photo by Tibor Nagy/flickr/CC.

This is Part I of a two-part series.

There’s high excitement on this lovely afternoon as a male ruby-throated hummingbird guzzles at our feeder. It’s my first sighting of this wee bird this year. “Oh, have I been waiting for you!” Last spring’s first long distance traveler made his fueling pit stop in our garden around this time so I was prepared for today’s little fella.

Shimmering green with the identifying ruby throat patch flashing in the sun, he perches for a long while, taking in the homemade sugary solution. “Drink up, my friend.” If there’s a repeat of the previous years’ pattern, this particular hummer will continue his journey north to other breeding grounds and a short time later two or sometimes three other hummingbirds will frequent our garden and make this area in Northern Virginia their summer home. Zooming, flitting, hovering and thoroughly delighting, our resident hummingbirds have become very special guests in our wildlife habitat.

So, what’s the secret to supporting these extraordinary creatures during their stay here in the Mid-Atlantic? It’s not simply hanging up a sugar-filled feeder. Continue reading

How to Control Mosquitoes Without Killing Pollinators and Other Important Wildlife

Aedes aegypti, the mosquito that can spread viruses like Zika and Dengue.

Aedes aegypti, the mosquito that can spread viruses like Zika and Dengue. Photo courtesy USDA.

by Susan Gitlin.

Warm weather and mosquitoes will be here before you know it, leading many of us to look for ways to enjoy the outdoors without being pestered by those annoying little—and sometimes disease-bearing—biters.

There is a lot of information being disseminated by health organizations about health risks to humans from mosquito bites (see CDC links, below). But besides protecting ourselves from being targets, we need to work at eliminating mosquito habitat and controlling their numbers. There are a number of ways we can do this safely and effectively.

Because mosquitoes have no trouble flying from yard to yard, the best way to combat them is to work with our neighbors to collectively identify and implement opportunities to reduce mosquito populations. Below is a set of approaches that are suggested by entomologists, public health organizations, and agricultural extension programs.

1. Eliminate potential mosquito-breeding grounds. Mosquitoes can breed in any water that stagnates for just 2 or 3 days. Actions to remove potential mosquito habitat include:  

  • Unclogging gutters
  • Covering, turning over, or moving indoors any equipment, containers, or toys that might collect water
  • Straightening sagging tarps or other covers
  • Filling in areas under outdoor faucets or air conditioning drains
  • Repairing damaged screens on rain barrels
  • Removing English Ivy (The dense nature of ivy allows it to hold in pooled water where mosquitoes can breed, provides a humid area that mosquitoes like, and protects mosquitoes from pesticide sprays.)

2. For areas of uncovered water, like ponds or bird baths, consider these approaches: 

  • Changing the water regularly
  • Using Mosquito Dunks ® (deadly to mosquito, blackfly, and fungus gnat larvae, but harmless to other living things), or
  • Keeping the water moving (e.g., with a fountain)
Our bees need to be protected from pesticide spraying.

Our bees need to be protected from pesticide spraying.

3. Treat mosquitoes like foes, but treat bees and other beneficial insects like the friends they are! The pesticides used to kill mosquitoes also kill other invertebrates, including pollinators and other insects—insects on which birds feed and insects that eat mosquitoes. Mosquito-spraying companies typically use pesticides of a group of chemicals called pyrethroids, many of which are highly toxic to honeybees, fish, and small aquatic organisms.

4. If you spray pesticides or hire a company that provides such services, please consider taking the following precautions and/or asking the pesticide spraying company to do the same:  

  • Spray only in the early morning or early evening. Most pollinators are not out and about during these time periods.
  • Do not spray flowering plants. (One company that provides pesticide spraying services says that before spraying flowers they “shoo” away bees with bursts of air. It is doubtful that this truly protects bees, as the majority of native bees are less than ¼” long and therefore difficult to spot. Moreover, bees will return immediately to those flowers, either into the path of the spray or to the flowers, where there may be pesticide residue.)
  • Make sure that no spray enters your neighbors’ yards, and notify your neighbors before you spray so that they can take any desired or necessary precautions to protect any bees or other insects that they have in their yards.
  • Consider using nontoxic repellants in lieu of the toxic pesticides. Some mosquito-spraying companies offer such alternatives.
Many mosquito-spraying companies use Bifenthrin which is highly toxic to bees, fish and aquatic organisms. It is also considered a possible human carcinogen by the EPA.

Many mosquito-spraying companies use Bifenthrin which is highly toxic to bees, fish and aquatic organisms. It is also considered a possible human carcinogen by the EPA.

5. If you use sprays, do so only when needed, and not on a preemptive basis. (Spraying on a predetermined schedule can waste pesticide product, and therefore money, and may also contribute to the development of pesticide-resistant mosquitoes.)

By taking these steps, we can work together as a community to fight this annoying pest while protecting our other precious environmental resources.

Useful websites:

Centers for Disease Control and Prevention:
Westnile Prevention & Control
Avoid Mosquito Bites 

Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses Fact Sheet

Mosquito Control—Environmental Protection Agency

Avoid Asian Tiger Mosquitoes—Maryland Department of Agriculture

Backyard Mosquito Management—Beyond Pesticides

Honeybee Love: Keeping Honeybees Safe While Using Pesticides

Mosquito Dunks ® Fact Sheet

Much thanks to Susan Gitlin for allowing me to post her article. How to Control Mosquitoes Without Killing Pollinators and Other Important Wildlife originally appeared on the Arlington Regional Master Naturalist site. Susan is a Virginia Master Naturalist and enthusiastic pollinator advocate.

Zika Virus Threat: Don’t Double Down on Trouble

Editorial by Miles Benson.

First responders to any Zika virus threat in this country had better be careful. Very careful.

The worst consequences of exposure to the disease itself are scary. But those fighting Zika should avoid tactics that risk piling on collateral damage. Elected officials charged with protecting public health and also those appointed to similar positions in the numerous local, state and federal agencies whose job it is to combat health emergencies on the ground should also recognize and try to limit an additional problem. That concern is whether, and how much, any new chemicals employed widely against Aedes aegypt, the mosquito that carries the virus, will add to the toxic chemical brew that has been building up in the environment over the past 50 years of agricultural and industrial commerce.

1940's nostalgia. A time when we were encouraged to spray neurotoxins indoors.  Actually, I think we still are. Photo: Office for Emergency Management. Office of War Information. Domestic Operations Branch. Bureau of Special Services. (03/09/1943 - 09/15/1945)

We’ve come a long way, baby? 1940’s nostalgia.
Photo: Office for Emergency Management. Office of War Information. Domestic Operations Branch. Bureau of Special Services. (03/09/1943 – 09/15/1945)

The public currently is exposed to tens of thousands of chemicals deemed “safe” mainly by people making and selling them. A rising chorus of concern is being voiced by environmentalists who question the safety of these chemicals, particularly when they become mixed with other toxins the public encounters daily. Many fear that a half century of exposure to environmental contaminants is associated with neurological defects, including autism, memory loss, mood changes, disorientation, infertility and genetic anomalies throughout our population.

Horror Story

Today, Americans are watching a horror story unfolding across Central and South America where women infected by the Zika virus are giving birth to children with abnormally small heads, a condition called microcephaly, that is associated with incomplete brain development. While the public may expect that massive spraying of pesticides would prevent outbreaks here, the New York Times reported that the Aedes aegypti mosquito is “relatively impervious” to outdoor spraying. That might mean more reliable and perhaps more lethal chemical formulas will be deployed by manufacturers if Zika outbreaks here begin to occur and trigger public panic.

We live in a sea of uncertainty. Zika could spread to the continental U.S… or not.

In Florida, the Aedes aegypti mosquito has been around for several years and experts in and outside of government believe existing pesticide spraying practices, including what are called “adulticides,” pose no unreasonable major threat to public health. But a 2009 report by the state’s Coordinating Council on Mosquito Control, funded by the University of Florida, described in cautionary terms the trade-offs we may be facing: “Since it is currently impossible to predict the long-term consequences of human exposure to synthetic compounds, including mosquito control agents, a prudent strategy is for society to reduce all unnecessary chemical applications.”

CDC Zika Virus Prevention

CDC Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses Fact Sheet

CDC Mosquito Bite Prevention Fact Sheet

Mosquito Control without Pesticides!

Virginia ‘Rabbit Proof’ Native Plants

Precious pink wiggly nose, slender silken ears, a fuzzy snowball of a tail  — all wrapped up in a cuddly but voracious plant-chomping package. Ahhh, our Eastern cottontail rabbits (Sylvilagus floridanus) are undeniably adorable but they can be destructive in gardens, continually reducing a plant of its foliage until it (the plant) runs out of energy and expires.

An Eastern cottontail nibbles grasses. Photo by Matthew Hunt/flickr/cc.

There aren’t any cottontails foraging in our garden currently — perhaps because we have a fox, a few hawks and a high number of domestic dogs and free-roaming cats in our neighborhood. Rabbits are certainly fair game to all sorts of predators. The Virginia Department of Game and Inland Fisheries writes, “Cottontails have been referred to as the “protein pill” of the animal kingdom. They are perhaps the most heavily preyed upon game species in Virginia. In most years, 80% or more of adult cottontails are killed.”

I have seen the damage a few marauding cottontails can do so at the request of a client, who reluctantly surrendered his garden to the bunnies, I did some hopping around on the web and found that there’s very little information out there on native plants that rabbits find unpalatable. Our deer receive all the attention.

I then turned to the people who I could count on to garden with native plants: the Virginia Master Naturalists, Arlington Regional Chapter (or ARMN, my alma mater). “What non-woody plants do your bunnies ignore?” I asked. Their comments and observations were crossed referenced with the information I found online and the following document was generated. A checkmark indicates if the rabbit-rejecting plant info was found through the web, ARMN, or both.

Continue reading

How I Killed a Tree (and the Lessons I Learned)

This was a sad day for me and the oak.

This was a heartbreaking day for me.

Once upon a time, not long ago, I shared my property with a handsome, thriving tree.  It’s now dead.  The oak had lived for 55 years, less than half its natural lifespan.  While alive it provided services to many.  It was a perch for birds, a home to squirrels and a source of food and shelter for an untold number of other life forms.

It made me happy.

My tree is gone now, chain-sawed, chipped and hauled away.  I think I helped kill it.  No, actually (full disclosure here) I now know that I did.

Trees are such familiar life forms themselves that we assume we know all about them and what’s best for them.  But there are so many surprisingly interesting things about trees that most of us don’t know but would be delighted, and wiser, to discover.

Why did this fine oak die?  What actions helped to speed its untimely death?  What would I do differently today?  I found my answers in a particularly dynamic lecture given by Joseph Murray, professional educator and arborist, and through some additional investigative research and personal observations. Continue reading