Embracing the Shade: Summer and Fall

Is it possible to have a perennial shade garden with continuous bloom throughout the summer and fall?  By June, the trees are fully leafed out, sheltering our home from the summer sun’s strong rays. That means that the garden is in the shade, too. Will anything be blooming? You bet.

Spicebush Swallowtails nectaring on Bottlebrush Buckeye

Spicebush Swallowtails nectaring on Bottlebrush Buckeye

Some spring bloomers, like Heartleaf Foamflower (Tiarella cordifolia) and Virginia Goldenstar (Chrysogonum virginianum), also called Green and Gold, may continue their display into the summer months. While not yet blooming, the leaves of White Wood Aster (Eurybia divaricata) join the violets, ferns, and Spreading Sedge (Carex laxiculmis) to form a ground cover blanketing much of the garden. Arching four to five feet above them are long sprays of Goat’s-beard (Aruncus dioicus) a.k.a. Bride’s Feathers’ tiny white flowers, lighting up the deep shade. June brings Rosebay Rhododendron (Rhododendron maximum) and Wild Hydrangea (Hydrangea arborescens) blossoms, too.

Bottlebrush Buckeye (Aesculus parviflora) is part of the shrub layer in the woods behind our house. In July, this reliable bloomer with its large palmately compound leaves and tall spikes of white tubular flowers attracts Ruby-throated Hummingbirds in addition to Spicebush and Eastern Tiger Swallowtails.

Dark form Eastern Tiger Swallowtail nectaring on Bottlebrush Buckeye

Dark form Eastern Tiger Swallowtail nectaring on Bottlebrush Buckeye

Last summer we were surprised to see dark morph Tiger Swallowtails nectaring on the Bottlebrush Buckeye. By adopting this Pipevine Swallowtail-like coloration disguise, the Tiger Swallowtails gain some protection from being eaten by birds and other predators who have learned of the Pipevine Swallowtail’s toxicity. The dark morph occurs most frequently in areas where Pipevine Swallowtails are present. Maybe Dutchman’s Pipevine (Aristolochia macrophylla) and its namesake swallowtail are increasing in our area!

Courting Zabulon Skippers on Purple Giant Hyssop

Courting Zabulon Skippers on Purple Giant Hyssop

July is also the beginning of Purple Giant Hyssop’s (Agastache scrophulariifolia) long bloom, lasting well into September. We have it in both deep shade and a spot that gets a few hours of afternoon sun, blooming dependably in both locations. This herbaceous plant is a great choice for a woodland garden, with a growth form that is similar to Butterfly Bush. In our garden, butterflies from the smallest skippers to the largest swallowtails love Purple Giant Hyssop. Bees love it, too, and even hummingbirds may drink from the nectar-packed purple flowers.

Eastern Tiger Swallowtail nectaring on Purple Giant Hyssop

Eastern Tiger Swallowtail nectaring on Purple Giant Hyssop

Pollinators can’t resist Mountain Mints.

Sweat Bee (Lasioglossum species) on Short-toothed Mountain Mint

Sweat Bee (Lasioglossum species) on Short-toothed Mountain Mint

I decided to try Short-toothed Mountain Mint (Pycnanthemum muticum), also called Clustered Mountain Mint, the only one of the Mountain Mint (Pycnanthemum) species I thought could tolerate some shade. I put it in the one location that gets about four hours of afternoon sun, and I got lucky. While not as robust as it would be in a sunnier spot, it’s doing well, its tiny magenta and white blossoms enticing the smaller butterflies like azures and skippers throughout July and August.

Summer Azure nectaring on Short-toothed Mountain Mint

Summer Azure nectaring on Short-toothed Mountain Mint

As summer progresses, False Sunflower (Heliopsis helianthoides) radiates bright yellow sunbursts at the wood’s edge from July well into September.

Sweat Bee (Agapostemom species) on False Sunflower (Heliopsis helianthoides)

Sweat Bee (Agapostemom species) on False Sunflower (Heliopsis helianthoides)

Eastern Tiger Swallowtails and Bumble Bees are frequent diners at Great Blue Lobelia (Lobelia siphilitica), open for business during August and September.  Even Ruby-throated Hummingbirds will stop here for a drink.

Eastern Tiger Swallowtail nectaring on Great Blue Lobelia

Eastern Tiger Swallowtail nectaring on Great Blue Lobelia

Also in August, after gathering energy from the sun from the earliest spring days when its leaves begin to emerge, White Wood Aster blinks on its light show of white blossoms, illuminating the dense shade through October. The delicate blue disk flowers of Carolina Elephantsfoot (Elephantopus carolinianus) provide a complementary offset in August and September.

White Wood Aster

White Wood Aster

Butterfly traffic slows by September, but Black Swallowtails may still lay eggs this late, sometimes on my cooking herbs (parsley and dill).

Black Swallowtail caterpillar eating parsley

Black Swallowtail caterpillar eating parsley

Last fall we hosted a chrysalis on a hot pepper plant.

Black Swallowtail chrysalis on pepper plant

Black Swallowtail chrysalis on pepper plant

More aster family members begin their fall performance now, including Blue Wood Aster (Symphyotrichum cordifolium),

Blue Wood Aster with Bumble Bee

Blue Wood Aster with Bumble Bee

Wreath Goldenrod (Solidago caesia),

Wreath Goldenrod

Wreath Goldenrod

and Zigzag Goldenrod (Solidago flexicaulis), in bloom and offering nectar through October or early November. Like White Wood Aster, all of the foliage of these species emerged in early spring from the winter’s leaf cover.

All of these summer and fall blooming species have a reproductive strategy that includes clusters or spikes of flowers that bloom gradually over a period of many weeks, increasing each plant’s chances of pollination by bees, butterflies, and others, and resulting in a long colorful garden display.When successfully pollinated, Purple Giant Hyssop, Carolina Elephantsfoot and Woodland Sunflower offer Chickadees, Goldfinches and other birds a fall bounty of food.

Goldfinch eating Elephant's Foot seeds

Goldfinch eating Elephant’s Foot seeds

Resident and migrant birds dine on the bright red fruit of Spicebush (Lindera benzoin) and Flowering Dogwood (Cornus florida) and the dark blue fruit of Sassafras (Sassafras albidum) and Blackhaw Viburnum (Viburnum prunifolium). This is after a busy season of acting as caterpillar food plants – Spicebush and Sassafras for Spicebush Swallowtails, Flowering Dogwood and Blackhaw for Spring Azures.

Flowering Dogwood fruit

Flowering Dogwood fruit

In October and November, Witch-hazel’s (Hamamelis virginiana) spidery yellow blossoms complement the fall foliage.

Witch-hazel flowers and fruits

Witch-hazel flowers and fruits

The bright red fruits of Winterberry Holly (Ilex verticillata) may last until late winter, when hungry birds finally eat them.

Winterberry Holly berries

Winterberry Holly berries

Little maintenance is required in this woodland garden. Because the plants have filled in to form a ground cover in most places, there is little weeding to do. We primarily use naturally fallen leaves as mulch, although we may supplement with a bit of prepared leaf compost around the front edges, in deference to our homeowners’ association’s sensibilities.

When we were trying to grow lawn in the shade, it was sparse, and we had problems with standing water after a heavy rainfall. Not anymore. The trees, shrubs and other plants in the garden, as well as the leaf litter, help the soil to absorb rainfall. The shade keeps the soil from drying out too quickly. So once these plants are established, watering is only required when drought conditions become extreme.

Not a bad performance for a woodland garden. And it brings so much pleasure!

Notes:

This is part 3 of a 3 part series.  To see parts 1 & 2, see A Butterfly Garden That Embraces the Shade and  A Butterfly Garden That Embraces the Shade – Spring.

This post was adapted from an article that was originally published in the Summer 2013 issue of Butterfly Gardener, a publication of the North American Butterfly Association.

A Butterfly Garden that Embraces the Shade – Spring

Spring Azure nectaring on Virginia Sweetspire

Spring Azure nectaring on Virginia Sweetspire

Our townhouse has a southern exposure, with deciduous trees and the garden on the south, east and west sides, and a common wall with another home to the north. From November through early April, with the leaves off the trees we get a lot of sun, helping to keep the house warm and the heating bills low. As the leaves unfold, the house and garden is well shaded, minimizing the need for air conditioning. “Passive solar”, courtesy of nature, free for the taking. We love the trees.

In nature, different species need to spend parts of their lives at different levels of the forest, some at or below ground level, some just above it, some a few feet higher in shrubs, and others in the trees, even all the way to the tree canopy. So the strategy for our garden is to have a broad diversity of plants mimicking a small slice of deciduous woodland, with a mix of trees, shrubs, and herbaceous plants including perennials, ferns and sedges.

Having a good mix like this accommodates a wide variety of interesting residents, including butterflies, birds, bees, moths, spiders, wasps, flower flies, ants, tree crickets, katydids, and others I’m still trying to identify. A good mix of critters means that they’ll all help keep each other in balance, with no one species dominating, and no need for chemical intervention.

Bad-wing Moth with white form of Common Blue Violet

Bad-wing Moth with white form of Common Blue Violet

During the winter months we enjoy the silhouettes of the trees, shrubs and spent perennials, and the birds that visit them. In March the transition to spring begins, with buds swelling and leaves beginning to emerge from the soil. By April the first flowers appear, at multiple layers in the garden.

Before the trees unfold their leaves, among the first blossoms to appear are those of Red Maple, Northern Spicebush, and Golden Ragwort. Although Mourning Cloaks generally prefer sap, I have actually seen them nectaring on Red Maple flowers. Spring Azures are pretty eclectic in their beverage tastes, even sipping from the starburst yellow flowers of Spicebush.

Heartleaf Foamflower, Green and Gold, Creeping Phlox and Canadian Wildginger quickly join the mix, while Virginia Creeper leaves begin to unfurl, adding to the ground cover.

Spring Garden - Foamflower, Golden Ragwort, Virginia Creeper, Christmas Fern

Spring Garden – Foamflower, Golden Ragwort, Virginia Creeper, Christmas Fern

As the days warm in April, violets begin to bloom. We have three well-established species: a white form of Common Blue Violet, the purple Schrank Alpine Violet, and Striped Cream Violet. They are spreading with the aid of ants, who eat the tasty elaiosome attached to violet seeds and then discard the seeds, effectively planting them. Last year a friend gave us a species with interesting lobed leaves, Early Blue Violet. All are available for fritillaries to lay their eggs nearby in late summer so their caterpillars, after spending the winter in leaf litter, can feed on them as both begin to grow in spring.

By late April or early May, Golden Zizia, Spotted Geranium, and Greek Valerian are all in bloom. Black Swallowtails may use Golden Zizia as caterpillar food plants, although they are also very willing to use the parsley and dill we grow in pots on the kitchen patio.

Spring Azure nectaring on Spotted (or Wild)Geranium

Spring Azure nectaring on Spotted (or Wild)Geranium

May brings blossoms at all levels of our woodland garden. Tuliptrees flower as high as their canopy, attracting bees with their copious nectar. Flowering Dogwood’s white bracts and Blackhaw Viburnum’s large round clusters of tiny white flowers light up the understory.

Flowering Dogwood

Flowering Dogwood

The shrub layer is graced with Gray Dogwood, Mountain Laurel, and Virginia Sweetspire. Many Azure butterflies favor dogwood and viburnum flower buds as caterpillar food sources, and will lay their eggs there. Ants protect Azure caterpillars from predators in exchange for the sweet honeydew they excrete.

Silver-spotted Skipper nectaring on Mountain Laurel

Silver-spotted Skipper nectaring on Mountain Laurel

Leaves of White Baneberry (a.k.a. Doll’s Eyes) and Common Ladyfern, Marginal Woodfern, Christmas and Northern Maidenhair Ferns are now available for perching or basking platforms. The male Zabulon Skipper pictured here is working to attract a mate.

Zabulon Skipper posing for a prospective mate

Zabulon Skipper posing for a prospective mate

While I watched him, when another butterfly flew by, regardless of species – Red Admirals, anglewings or swallowtails – he chased them away. With mission accomplished, he returned to a horizontal perching platform provided by White Baneberry leaves or the tips of a Christmas Fern frond, both along the edge of the moss path that curves through the garden. They offer the perfect elevation and exposure for the skipper to show himself off to prospective mates.

The secret is to choose plants that are naturally adapted to a woodland environment. They’ll be happy with the soil, moisture, and available light with minimal intervention from you, and no chemical fertilizers. Most of these perennials bloom for about 6-8 weeks, although Green and Gold may bloom throughout the summer if you deadhead. The shrubs usually flower for 2-3 weeks. After a warm winter, blooming may begin weeks earlier than usual. This past January I saw Golden Alexander in bud – a little scary!

So there is plenty of interest in the garden in spring. But what will bloom in the shade of summer and fall? And what butterflies will visit? Stay tuned!

See below for a list of scientific names for the plants featured in this post:

Red Maple (Acer rubrum)
Northern Spicebush (Lindera benzoin)
Golden Ragwort (Packera aurea)
Heartleaf Foamflower (Tiarella cordifolia)
Creeping Phlox (Phlox stolonifera)
Green and Gold (Chrysogonum virginianum)
Canadian Wildginger, Wild Ginger (Asarum canadense)
Common Blue Violet (Viola sororia)
Schrank Alpine Violet, Labrador Violet, American Dog Violet (Viola labradorica)
Striped Cream Violet (Viola striata)
Early Blue Violet (Viola palmata)
Golden Zizia (Zizia aurea)
Spotted Geranium (Geranium maculatum)
Greek Valerian (Polemonium reptans)
Tuliptree (Liriodendron tulipifera)
Flowering Dogwood (Cornus florida)
Blackhaw (Viburnum prunifolium)
Gray Dogwood (Cornus racemosa)
Mountain Laurel (Kalmia latifolia)
Virginia Sweetspire (Itea virginica)
White Baneberry, Doll’s Eyes (Actaea pachypoda)
Common Ladyfern (Athyrium filix-femina)
Christmas Fern (Polystichum acrostichoides)
Marginal Woodfern (Dryopteris marginalis)
Northern Maidenhair Fern (Adiantum pedatum)

Note:  This is part 2 of a 3 part series.  To see part 1, click here: A Butterfly Garden that Embraces the Shade.  For Part 3, click here:  Embracing the Shade:  Summer and Fall

This article was also published in the Spring 2013 issue of Butterfly Gardener, a publication of the North American Butterfly Association.

A Butterfly Garden that Embraces the Shade

Winter doesn't want to quit!

Winter doesn’t want to quit!

Feeling like spring will never arrive? Let’s fantasize a little. Let’s think about gardens in bloom.  And butterflies.  We’ll soon be seeing them.  Really!

When you think about a butterfly garden, shade may not be the first attribute that comes to mind.  But really, maybe it should be. Or at least it should be one of the first.

Ok, maybe not shade for shade’s sake, but for the food plants that cast it.

When you think about it, many butterflies rely on woody species – trees or shrubs – as food plants for their caterpillars.  For example, of the six species of swallowtail butterflies that are possible where I live in New Jersey, four require trees or shrubs as food plants, and one uses a shade tolerant vine.  Most of the hairstreaks, many of the azure and brushfoot species, and the Hackberry and Tawny Emperor all require trees or shrubs as their caterpillar food plants.

Hackberry Emperor

Hackberry Emperor

Other butterflies have evolved to use shade tolerant herbaceous species like violets, Black Cohosh, and Golden Alexanders as food plants.  So a shade garden can be a really valuable asset to the butterflies in the neighborhood.

Violets

Violets

My husband and I chose our house because we like the natural woods that surround us on two sides, preserved 24 years ago by the developer.  Even though we live in a townhouse community at the edge of a small town, the woods give us the illusion of living in the country.  We love the trees for their own beauty as it evolves through the seasons. And we love the birds they bring to feast on the fruits and insect protein that are abundant here.

Tufted Titmouse in Blackhaw Viburnum (Viburnum prunifolium)

Tufted Titmouse in Blackhaw Viburnum (Viburnum prunifolium)

Carolina Wren

Carolina Wren

Somewhat to our surprise, we found we also had butterflies. As we learned more about them, we realized we had some very desirable territory for butterflies, and other critters, too. Finally, I understood when I saw an Eastern Tiger Swallowtail flitting high up in the White Ash or Tuliptrees, that it was a female laying her eggs on their leaves.

Tuliptree (Liriodendron tulipifera) blossom

Tuliptree (Liriodendron tulipifera) blossom

Eastern Tiger Swallowtail

Eastern Tiger Swallowtail

The Mourning Cloak may have been drawn here because of the elm trees in the woods behind the house.

Mourning Cloak nectaring at Red Maple (Acer rubrum) blossoms

Mourning Cloak nectaring at Red Maple (Acer rubrum) blossoms

Why were Spicebush Swallowtails visiting our woodland garden? It’s the food plants, silly; their namesake Spicebush is present here, and so are Sassafras trees, which they are also willing to use.

Spicebush Swallowtail with Purple Giant Hyssop (Agastache scrophulariifolia)

Spicebush Swallowtail with Purple Giant Hyssop (Agastache scrophulariifolia)

The birds and butterflies have a somewhat mutually beneficial relationship. It’s true that the birds may be interested in eating the butterflies sometime during their lives, but on the plus side, birds keep insect predators of butterflies in check.  As a bonus, birds also provide dietary supplements for butterflies that are inclined to dine on mineral sources.  The Silver-spotted Skipper pictured here is sipping the nutritious offerings conveniently left by one of the local birds in the form of its droppings.

Silver-spotted Skipper getting minerals from bird droppings

Silver-spotted Skipper getting minerals from bird droppings

After stoking up, this little butterfly was off, maybe in search of an appropriate place to lay her eggs, like a near-by Black Locust tree.

Red Maple, White Ash, Sassafras, Flowering Dogwood, Blackhaw Viburnum, and a Crab Apple all grow in the common area along side our house.  As the trees grew over the years, they shaded out the lawn surrounding them.

Before the shade garden

Before the shade garden

Moss developed where grass once grew.  Chickadees plucked the moss until their beaks were full, gathering the soft lush material to line their nests. This was great!

Chickadee in Blackhaw Viburnum (Viburnum prunifolium)

Chickadee in Blackhaw Viburnum (Viburnum prunifolium)

So we decided to embrace the shade. It was futile trying to maintain a lawn that disappeared by July every year.  We got permission from our homeowners’ association to plant a shade garden under the trees and in place of the lawn that once grew next to them. This was a win for our association, since money would no longer have to be spent fruitlessly reseeding, fertilizing and mowing the lawn, or more accurately, the mud.

Now we have a constantly changing display of blossoms, ferns, sedges, foliage, and fruits. We took advantage of the moss, encouraging it to cover a winding path through the garden. There is always something blooming from about mid-April to the end of November; sometimes longer if the Witch-hazel is especially happy.  After that, the fruits offer visual appeal for us, and food for our local residents.  The birds love the new habitat, and we have more butterflies than ever, enjoying nectar and other food sources, and looking for a place to start the next generation.

Our wildlife-friendly shade garden

Our wildlife-friendly shade garden

I have my desk facing a second floor window so I can be easily distracted by birds, or watch a female Spicebush Swallowtail pause on a Sassafras leaf to lay an egg, then float down to lay another on the Spicebush that entices her below.

In future episodes, I’ll tell you more about the plants here and the critters we see enjoying them.

Note:  This is part one of a 3 part series.  For part 2, click here, A Butterfly Garden that Embraces the Shade – Spring.  For part 3, click here,  Embracing the Shade:  Summer and Fall

This article was adapted from one that was published in the Winter 2012 issue of Butterfly Gardener, a publication of the North American Butterfly Association.