Monarch Butterfly & Asclepias (Milkweed)

One of my favorite aspects of summer is seeing all the butterflies, like exquisitely colorful silk tapestries, fluttering throughout my garden. Butterflies are from the insect family, Lepidoptera, which includes butterflies, skippers and moths. Over 151 species of butterflies have been recorded in the state of Maryland. Many butterflies have names that conjure up images of a land replete with fairies and unicorns; names such as wood nymphs, brushfoots, satyrs, elfins, and duskywings. Butterflies are beautiful, tough yet fragile, and can put a smile on the face of even the most negative nature-averse person on the planet.

Tiger Swallowtails on Joe Pye Weed

Many butterflies have very particular needs throughout their life cycle. Some are very specialized and require a specific host plant family, or sometimes only one particular host plant, to feed on during their larval stage as caterpillars. In addition, some require specific plants that they use as nectar sources; perhaps it is the quality of the nectar, the shape of the flower, the specific bloom time, or simply a nectar plant that tends to grow in the same habitat as the larval host plants and through evolution have become the preferred flowers for nectar consumption simply because they were the closest flowers. Unfortunately, with development systematically encroaching on wild areas, and residential and commercial gardens containing few, if any, native plants, these important food sources, that are essential to the survival of future generations of butterflies, are disappearing quickly. Because of this, many butterfly species have declined and some have even become endangered.

Tiger Swallowtail on Monarda

The good news is that you can help. Homeowners can have a crucial impact on the future of our butterfly population by planting more native plants in their gardens. As this year’s growing season comes to an end, we can help butterflies now by helping them to prepare for winter. Butterflies spend their winter in a variety of ways. Some butterflies, like the famous Monarch, migrate south for the winter, traveling an exhausting, perilous journey across thousands of miles. Other butterflies over-winter as eggs, chrysalis, or caterpillars, hiding under fallen leaves or tucked away on the undersides of branches. Still others, such as the Mourning Cloak, spend the winter as adult butterflies, hiding under the shaggy bark of trees in a state of torpor, or semi-hibernation. But all butterflies share one thing in common, in order to survive the winter; in late summer and early autumn they all need extra energy and nutrition in the form of nectar.

It is no accident that there are many native plants that bloom toward the end of summer. Through hundreds, or even thousands, of years of evolution, flowers adapted their bloom period to coincide with the time when pollinators are available and in need of nectar. Simply put, that means that there are many beautiful flowers to choose from that will suit nearly every gardener’s (and butterfly’s) taste. In order to attract the most butterflies and have a beautiful end-of-season garden, be sure to provide an assortment of native plants that bloom at different times, right up until the end of the growing season. Here is a list of some of my favorites that are easy to find and easy to grow.

[Note on availability from Larry Hurley, Perennial Buyer: Availability of perennials for sale at Behnke Nurseries varies throughout the year, with the best availability from mid-April to early June. Some of the items described below, such as the wild form of Black-eyed Susan, Rudbeckia hirta, I have been unable to find for sale. Vernonia noveboracensis and Conoclinium coelestinum are occasionally but not routinely, available. You can always email me at lhurley@behnkes.net to check availability on perennials you are looking for.]

Joe Pye Weed and Goldenrod

One of my all-time favorites, and a seemingly infinite source of nectar, is Joe Pye weed (Eupatorium species). Depending on the variety, Joe Pye can grow from a diminutive two feet tall, to an astounding twelve feet tall. The hazy purple-pink flowers are actually umbels of numerous tiny flowers that produce copious amounts of nectar that every butterfly in the neighborhood would have a hard time passing up. Some varieties, such as common Joe Pye weed, Eupatorium dubium, and spotted Joe Pye weed, E. maculatum, require soil that does not dry out. However, trumpet weed, E. fistulosum, can withstand drier soils. In my garden, however, I grow the cultivar, Eupatorium maculatum ‘Gateway’, and the plant does extremely well without any additional water (although I gave it plenty of water the first year until it became established). Joe Pye weed looks fantastic when planted in odd-numbered groups of three, five, or more. Try it with switchgrass, Panicum virgatum, or Indian grass, Sorghastrum nutans, for a stunning late-season effect.

Aster divaricatus

Other late season butterfly favorites are plants in the aster family. Asters are a diverse group of flowering plants that offer fall-blooming beauties for both the sunny and the shady border. The most easy-to-find asters include New England aster, Aster novae-angliae, and New York aster, Aster novae-belgii, both of which prefer full sun to partially sunny areas. These plants are popular in the nursery industry and many cultivated varieties are available with many different flower colors and plant heights to choose from. Asters can come in colors ranging from sophisticated light pink to arresting fuchsia, and from delicate sky blue to dramatic royal purple. Asters are easy to grow, just provide them with a bit of extra attention the first year. Asters also look better when grouped together and glow in the late summer garden when most other plants have petered out. Some varieties bloom late in the fall and the flowers look spectacular among the red, yellow and orange fall foliage. In addition, the non-cultivated varieties of both New England and New York aster are the host plant to the Pearl Crescent butterfly.

Phlox paniculata

A third favorite and a must-have for any butterfly garden, is tall garden phlox. There are many cultivated varieties to choose from, but one of my favorites is Phlox paniculata ‘David’. Some phloxes tend to get a bit of whitish mildew on their leaves, but not David. With its five-inch long panicles of pristine white, hay-scented flowers, David can take drought, average garden soil, and whatever else you throw at it. In addition, if seed heads are left to mature, you will soon find your garden full of David offspring, which tend to revert back to their wild nature and mature to different shades of vivid pink. In addition to ‘David’, ‘Eva Culum’, ‘Franz Schubert’ and ‘Katherine’ are the cultivars that I enjoy growing in my garden, but there are many other varieties to choose from. Phlox begins blooming in July and continues well into the end of August. I find that they are constantly visited by many different butterflies and hummingbird moths. [Note from Larry Hurley, Perennial Buyer: I have seen powdery mildew on Phlox ‘David’, but all things being equal, it develops fewer symptoms than many of the older selections. Others that are mildew tolerant include ‘Robert Poore’ and ‘Speed Limit 45’. This is the end of the Phlox sales season, so selection at this point is limited.]

No butterfly garden would be complete without our state flower, the black-eyed Susan. Rudbeckia hirta and other Rudbeckia species are tough garden plants that deserve their place in every garden. Although it seems that every gas station tends to have these plants, that should just give you more reason to consider planting them because they bloom for long periods of time and are very easy to grow. In addition to being a nectar source, American goldfinches and other seed-loving birds will flock to your flowers, if you let your plants go to seed. It is exciting to watch an American goldfinch clinging upside down from his own weight, carefully picking out the small black seeds. Letting the flowers go to seed also means you will probably be rewarded with additional black-eyed Susan seedlings the following year. As if all that isn’t enough, the uncultivated species, Rudbeckia hirta, is the host plant to the Silvery Checkerspot butterfly.

Goldenrod - Solidago rugosa Fireworks

An important group of plants to consider for feeding butterflies in late summer is the goldenrod (Solidago) genus of plants. Goldenrods are the quintessential nectar producing plants of our area. These plants can take drought, scorching heat, and even overcrowding, and still shine on. Their tiny yellow flowers growing along their slender stems must be an intoxicating source of nectar, because their flowers are never without the company of numerous pollinators. Goldenrods tend to be one of my favorite flowers. There are many different species and cultivated varieties to choose from that offer different shape and sized plants. All are exciting when grouped together with vivid purple asters, showy pink phlox, and smoky violet-pink Joe Pye weed. One of my particular favorites is Solidago rugosa ‘Fireworks’, which really does look like a parade of golden fireworks. But try a number of varieties; they all add sparkle to the flower border.

A lesser-known native plant which is a spectacular nectar source is New York Ironweed, Vernonia noveboracensis. This plant can grow up to six feet tall and likes full to part sun. Besides getting a layer of mulch in spring, the ironweed in my garden does not receive any additional water and still looks great. Its luminous purple flowers remind me of little puffs of woolen pompoms. Plant it in groups among black-eyed Susans and goldenrods for a dramatic effect. Purple and yellow are on opposite sides of the color wheel and the contrast of their vivid colors draw the attention of pollinators and people alike. For a more subdued effect, plant purple love grass, Eragrostis spectabilis, or purple muhly grass, Muhlenbergia capillaris, in the front of the border to mimic the purple color and create a more cohesive design. Regardless of what you plant it with, ironweed will look great in your garden.

Although there are many other late-blooming native flowers to write about, I wanted to switch gears and mention a few plants that would work for those homeowners who are blessed with shady areas in their yard. Tolerating excruciatingly hot summer temperatures this year, I have found myself spending more time in the shady parts of my yard which, at ten to fifteen degrees cooler than the sunny areas, are a respite during the summer months. Butterflies, too, enjoy a break from scorching heat and will travel into tree lined gardens in search of native beauties such as cardinal flower and white wood aster. Both of these native plants are late summer bloomers and offer rich nectar for hungry pollinating insects.

Cardinal flower, Lobelia cardinalis, is a stunning native wildflower. This plant is always a surprise to most people when they find out that this spectacular flower grows wild in our wooded areas. As its name implies, the cardinal red flowers rival the color of the red robes of the Cardinals in Rome. Larger butterflies, in particular swallowtails, seem to thrive on the nectar from this sensational plant. In addition, hummingbirds flock to the flowers and will fight over the area so that they do not have to share the tasty sweet liquid with any other hummer. I particularly enjoy the combination of cardinal flower in bloom planted with the non-natives Japanese painted fern and Brunnera macrophylla ‘Looking Glass’. The wide silver leaves of Looking Glass and the lacey silver and maroon leaves of painted fern, both compliment and contrast with the bright crimson of cardinal flower. And since cardinal flower can sometimes be a little leggy, underplanting Brunnera and ferns in front of cardinal flower will hide the cardinal flower’s lanky stems. Another excellent companion plant and a favorite of pollinators is a native called blue mistflower, Conoclinium coelestinum (formerly Eupatorium coelestinum.) Looking very similar to the annual blue ageratum, but much taller, the Wedgwood blue fuzzy flowers of blue mistflower create a striking vignette with cardinal flower.

By contrast, white wood aster, Eurybia divaricatus (formerly Aster divaricata), is a sophisticated subtle beauty. When in bloom, white wood aster plants nearly exhaust themselves by completely covering their stems with tiny white blossoms held high above glossy heart-shaped leaves. Since flowers are modest in size, white wood aster creates a stronger impression when planted in larger groups. Add white wood aster to your vignette of cardinal flower, Brunnera Looking Glass, Japanese painted fern, and blue mistflower. Throw in a few Christmas ferns for some deep green to tie in the color scheme and allow the eye to rest, and you have a shady border that will be the envy of the neighborhood. For a bold background to offset the dainty blooms and lacey foliage, plant some Annabelle or White Dome hydrangeas, which will, by this time, have lime green flower heads. Now you’ve taken the shady border to an entirely new level of ‘Wow’.

So the next time you decide to add some more plants to your garden, consider adding a variety of late season nectar sources for the butterflies. The colors of the flowers and the color and movement of the butterflies will bring you endless joy during the final days of summer.

Sidebar From Behnke’s Woody Plant Manager, Miri Talabac. Several native shrubs also serve as great nectar sources for butterflies and other pollinators. Sweetspire, Summersweet, Buttonbush, New Jersey Tea, several deciduous Azaleas are some of the most popular. (As with the perennials, some of these plants are more readily available in spring.)

Natalie Brewer
Master Gardener

By Natalie Brewer, Howard County Master Gardener

Berries with Fall Colored Foliage

Standing there unobtrusively, in fact barely noticeable, it seems my winterberry patiently awaits the passing of summer. Although it is unfair to say that it is unnoticeable now, for its lustrous deep green leaves look fresh and unfazed by the summer’s heat, winterberry seems to calmly pass the time while the rest of the garden is flowering itself into a frenzy of red, yellow, and purple.

Earlier in springtime, when the garden was replete with blossoms of pink, white, and blue pastels, diminutive white flowers emerged on the winterberry. They were inconsequential to humans. But the pollinators found them to be impressive.

So, if you believe that all good things come to those who wait, then you are in for a treat when autumn comes. Winterberry is a nice-enough plant during the rest of the year. But starting in autumn and throughout winter, winterberry stops playing nice. Like a high school senior hiding a slinky, strapless, red dress under the frumpy garb her mother made her wear to the prom, at the first sign of frost winterberry sheds its leafy robe to expose its dazzling drop-dead fire-engine red berries. With no leaves to distract, and every branch covered in luscious fruit, winterberry puts on a show while the rest of the garden finally takes a rest.

Brookside Gardens

Winterberry is certainly a show-stopper shrub. Known as Ilex verticillata, winterberry is one of our most prized native plants. Walking through the woods, you would have a hard time finding it in summer. But walk through the woods in winter, and you would have a hard time missing it. Whereas most folks think all hollies are evergreen, winterberry stands out by being deciduous. And whereas most folks are familiar with the prickly shiny deep green leaves of hollies, winterberry leaves are soft in comparison, with a fine serrated edge on a small oblong leaf. The Latin name, Ilex, means ‘evergreen oak’. So, while winterberry does not have the same stature and leaf structure and does not stay evergreen like its ‘oak-like’ holly cousins do, winterberry does have other traits in common, such as its ease of culture and its overabundance of berries.

Longwood Gardens

In its native range, which includes Maryland, winterberry prefers a very moist, almost swampy soil. However, give it regular garden soil, sun or part shade, and a drink during drought, and you will be rewarded with years and years of outstanding performance. Winterberry is not bothered by any pests or diseases. Its only demand is to be partnered with a willing male (another trait it has in common with the holly family), meaning a male winterberry plant that blooms at the same time, so that pollinating insects can do their magic. The nursery industry has made it easy to find a willing partner and has different male plants available to suit the lovely females. Winterberry plants produce more berries in sunnier locations, so be sure not to give it too much shade, and be aware that it may take a few seasons for the winterberry plants to start producing berries in large quantities.

So why should you plant a winterberry? Have you ever gone outside in mid-January and seen color, other than green or gray, in the garden? Imagine looking out your window, when all of the perennials have departed underground, all of the leaves have vanished from the branches of trees and shrubs, and seeing a beacon of bright color emanating from a single shrub, like a lighthouse in a dismal sea of gray. Now imagine the spectacle of color the winterberry flaunts when it snows; a crimson silhouette against a backdrop of pristine white.

Humans won’t be the only ones to notice the fluorescent red berries. Winterberry is a staple food source for many mammals and birds, particularly birds in the thrush family. The thrush family includes favorite backyard visitors, such as robins, wood thrushes, and bluebirds. Blue jays, catbirds, cedar waxwings, and mockingbirds also relish the juicy fruit. Winterberry berries are often passed up by birds until late winter or early spring. Therefore the birds have something to eat in early spring when there is little else available, and you get to enjoy the color of the gorgeous berries all winter long. Many birds enjoy stripping the berries from the branches during their spring migration back north, when they are ravenous for some extra nutrition while staking out territories and searching for mates. But don’t be tempted to eat any yourself. Holly berries and foliage are poisonous to people, so don’t (Don’t! Do Not!) bake a pie or make an herbal tea!

Winterberry is attractive in any garden setting, whether formal or casual, and makes for a nice green backdrop for summer-blooming perennials such as black-eyed Susan, tickseed, and switchgrass. Winterberry looks good as a single specimen plant, but looks striking when massed in odd-numbered groups. In addition, the berry covered branches are commonly used in floral displays, wreaths and garlands.

There are a number of cultivated varieties that you may find in the nursery trade. ‘Berry Nice’ has deep, glossy red berries and usually grows up to 6 feet tall. ‘Berry Heavy’ has a heavier set of fruit, which means more berries and more color for the garden, and gets a little taller at 6 to 8 feet tall. Use ‘Jim Dandy’ or ‘Southern Gentleman’ to pollinate either of these selections. For something different, try ‘Winter Gold’, which is not quite gold, but rather a pinkish-orange color that matures to a lighter gold. ‘Winter Gold’ usually grows to about 10 feet tall. Use ‘Southern Gentleman’ as a pollinator. ‘Sparkleberry’ is a hybrid between our native winterberry and a non-native selection. It too has abundant red fruit, but can grow even larger, up to 12 feet tall. Either ‘Apollo’ or ‘Southern Gentleman’ can be used as the male to pollinate this variety. A male plant should be used within 25 feet of the female plants, and you can use one male for every three to five females. Since winterberries are insect pollinated, monogamy is not an issue, and so that you get the most for your money, you should plant more females than males.

Please note that it is necessary to select specific cultivars of males to pollinate specific cultivars of females. This has to do with the origin of the cultivar. Winterberry has a large native range, and can be found growing from Quebec to Florida. Some cultivars are derived from plants that naturally grew in the northern part of the range, and they tend to flower later than other cultivars that resulted from plants which naturally grew in the southern part of the range (e.g., ‘Southern Gentleman’).

If you pair up a northern male with a southern female, or vice versa, they won’t flower at the same time, and therefore pollinators won’t be able to bring pollen to the female flower, and no berries will be initiated (unless perhaps, there are suitable plants elsewhere in the neighborhood, in which case you will have berries but not a lot). Therefore, be sure to ask your nursery salesperson for help in determining the correct male plant for your female cultivars.

So the next time you go plant shopping, go ahead and try some winterberry. Within a few short seasons, you will have wished that you had planted more of these shrubs in your garden. And your neighbors will wish that they had winterberry in their gardens, too.

By Miri Talabac, Woody Plant Buyer/Manager

Hydrangea quercifolia Pee Wee

I think it’s a safe bet to say that everyone has grown or at least seen hydrangeas; they permeate the American landscape. What many may not have experienced is the range of hydrangeas out there to try.

There’s a trifecta, if you will, of hydrangeas that are the most commonly encountered: Smooth (‘Annabelle’ is the star child of this group), Panicle (‘PeeGee’ is the one here) and Bigleaf (also known as mopheads, lacecaps, or simply Hortensias; there are a gazillion of these). Each beautiful in its own right, we’ll showcase these plus some others that we feel are among the best to grow.

Hydrangea quercifolia Pee Wee

While ‘Annabelle’ is the famous white snowball-flowered early summer showoff, there are other Smooth Hydrangeas out there. Try White Dome® if you want something more subdued and closer to the wild form (yes, they’re native!) as it’s a lacecap type. Two new varieties, Incrediball and Invincibelle Spirit are making their way into the market.

The former is a large-flowered white; the latter a rare pink. It’s also a pink-ribbon plant that benefits the Breast Cancer Research Foundation®. Bigleaf types have pink, purple, blue or white flowers in either mophead (ball) or lacecap (flat) forms. The recently developed Endless Summer® series gives you a longer flowering due to the ability to grow flower buds throughout the summer – something old varieties don’t do.

Endless Summer Hydrangea

A few other newbies do this too, like ‘Penny Mac’ and its little sister, ‘Mini Penny.’ Cultivars in another new series, Cityline™, are very compact and sturdy growers. They are named after European cities, hence Berlin and Vienna. Then there are fantastic oddball varieties with black stems, double lacecaps, or variegated foliage.

Hydrangea macrophylla Cityline Berlin

Panicle hydrangeas are branching out too. New cultivars like Pinky Winky™ and Quick Fire™ start turning pink from the bottom of the cluster up before the white flowers have even finished opening at the top. They also have spectacular fall color – rich russet-orange and bronze-red – where others just turn yellow.

Limelight® is popular for its pastel lime-green young flowers, and ‘Little Lamb’ is a more compact and smaller-flowered version of PeeGee so it doesn’t tend to arch under the weight of the flowers (which, admittedly, can look nice). White Diamonds™ has strong stems with large white flowers than open earlier than most.

Hydrangea quercifolia Little Honey

Oakleaf types have, you guessed it, oak-shaped leaves that are covered in downy silver fuzz in spring on soft, cinnamon-orange stems. Fall leaves are burgundy, red and caramel-orange, and I have seen a few of them remain on plants sheltered from strong winds well into early spring. Bark peels on older plants, an excellent feature in winter. Flowers are ivory-white, with some fragrance, and open in early summer.

Schizophragma hydrangeoides

Climbing hydrangeas are the best flowering vine for shady spots. They cling to bark, brick, or wood; although they are slower than most vines, I have seen them reach 50’ or more on tall tree trunks. There are three members of the hydrangea family that grow well here, and they’re all a mouthful: Climbing Hydrangea (Hydrangea anomala petiolaris), Japanese Hydrangeavine (Schizophragma hydrangeoides) and Woodvamp (Decumaria barbara), the latter being native in this area.

White flowers show up between late spring and early summer, and leaves turn yellow in fall (only Woodvamp can be evergreen). Climbing Hydrangea also has peeling bark like the Oakleaf types. Since they also take part shade, I like throwing Clematis in to scramble up through them and extend the flowering season.

Hydrangea quercifolia Snowflake

All hydrangeas prefer to be moist in well-drained soil that is at least slightly acidic. During drought, you should soak them every now and then. Afternoon shade and mulched roots will keep them cooler and less likely to wilt in than full sun. For the Bigleaf hydrangeas that have flowers that can change color, stronger acidity will give you purples and blues. Less acid soil that has some extra potassium will give you pink.

Smooth and Panicle hydrangeas flower on new growth and can be cut back in late winter with no worries; Oakleaf, Bigleaf, and Climbing types flower on old growth from the prior year, and if you prune before they flower you risk removing all your flowers for that year. Generally, though, most hydrangeas don’t even need regular pruning. Just sit back and enjoy the show!

Oakleaf Hydrangea – Hydrangea quercifolia

Hydrangea quercifolia Pee Wee - Fall Color

A hydrangea with oak-shaped leaves! What will mother nature think of next? How about peeling bark, downy-silver new growth, cinnamon-orange stems, fragrant flowers and rich fall color?

This hydrangea’s got it all. Flowers are an ivory-white and draw bumble bees and even some butterflies. The best feature may be the fall foliage colors – maroon, red, scarlet and caramel-orange.

While native a bit further south of here, they are still perfectly hardy and well-adapted to our soil. Give them full sun for best color, but they are probably happiest in afternoon shade, where their leaves can grow up to 10” long or so! Ideal soil is moist and well-drained.

Hydrangea quercifolia

This hydrangea flowers on growth from the previous year like the mophead/lacecap types, so should be pruned when needed after flowers fade – not in spring.

Hydrangea quercifolia Pee Wee

There are many varieties to fit any area, from ‘Sikes Dwarf’ maturing around 3’ tall to ‘Snow Queen,’ ‘Alice’ and ‘Snowflake’ that reach from 6 to 8’ tall. ‘Pee Wee’ is the most well-known variety, growing 4-5’ tall and wide in 10 years or so. ‘Little Honey’ is the chartreuse-leaved version.

Hydrangea quercifolia Little Honey

Virginia Sweetspire – Itea virginica

Itea virginica

This is another locally native shrub and fantastic for multi-season interest. White flower clusters abound in late spring, and fresh green leaves cover the arching branches until fall, when they become a beacon of burgundy, red, orange and yellow.

Winter stems tend to stay deep red on young branches, and the dense root system is great for erosion control.

Since the flowers have a light sweet scent, they are a great draw for pollinators – bees and butterflies alike.

Itea virginica Henry's Garnet

Full sun will give you the richest fall colors, but in the wild these plants can also be found with other understory plants in the brighter spots in the woods.

Itea virginica Little Henry

Moist soils are a plus, and Sweetspire can even be happy in wet conditions. Mature height ranges by variety – from about 2-4’ for Little Henry™ to 3-5’ for ‘Henry’s Garnet’ – and each can spread to about 6’ wide. Any pruning needed should be done after flowering.