Tuesday, September 08, 2009

Chrysanthemums: Jewels of the Fall Garden

Labor Day has just passed, and for many of us, it signals the near arrival of fall. Not surprisingly, a recent visit to my neighborhood Whole Foods market was greeted by an especially color sight. Mums. Mountains and mounds of them. And how timely. After all, as the sun slips lower in the sky, we'll find a new kind of light. An "autumn light" which is mellow, warm and golden, and almost seems to glow across our landscape. Gardeners, looking to respond to that gentle light, will find no plant which can echo the gentle colors of fall more kindly and completely than the chrysanthemum.

The chrysanthemum is often called the “queen of fall flowers,” and is actually the largest commercially produced flower in the United States, both as a potted plant, and in floral arrangements, where chrysanthemums are valued as one of the longest lasting cut flowers.
Mums are members of the Asteraceae (or Compositae) family, the largest family of flowering plants, and is related to asters, dahlias, marigolds, zinnias, and most other daisy-like flowers. A closer look at a plant will reveal that the single bloom is actually made up or “composed” (hence Compositae) of hundreds of small flowers or florets, with ray florets on the outer edge of the flower, and disk florets at the center of the blossom.

The origins of the mum take us to China at least as far back as the 15th Century B.C., where the plant was cultivated as a flowering herb for use in salads, brewing beverages for special celebrations, and curing headaches, possibly caused by those celebrations.

Please note that only the flower petals of today’s ornamental mums are edible. While there is an edible chrysanthemum called garland or vegetable chrysanthemum (Chrysanthemum coronarium), with leaves reminiscent of today’s ornamental variety, hungry gardeners should not attempt to eat the foliage of garden chrysanthemums.

During the eighth century A.D., chrysanthemums began to appear in the literature and art of Japan. Called Ki-Ku, “Queen of the East,” a single blossom of the flower was used as the crest of the emperor, and Chrysanthemum Throne is the common name for the Imperial Throne. Today, chrysanthemum is the national flower of Japan.

Chrysanthemums gained attention in the West in the 17th century, and were so-named by the botanist Linnaeus who combined the Greek “chrysos” with “anthemon” to describe a “golden flower.”

Of course, mums are a lot more than golden flowers these days. Horticultural breeding now provides a dizzying variety of forms, colors, and growth habitats. The National Chrysanthemum Society recognizes 13 different classes of mum, many of which are familiar to gardeners, such as spider, anemone, quill, spoon, and pompon, although marketing efforts also tout mums with fanciful names such as football mums, maxi-mums, pin cushion, and many more.

Beyond interesting floral shapes, these jewels of autumn are resplendent in russets and gold, red, yellow, gold, orange, pink, purple and white, and can be planted in solid masses of color, or mixed together like a living tapestry.

Of special interest is a fairly recent and popular mum, ‘Silver and Gold,’ which provides variegated foliage along with attractive blooms and desirable winter hardiness.
Chrysanthemums can be sited almost anywhere in the landscape, in planters by a front door, as border plantings along a driveway, or mixed into a year-round garden bed to provide a quiet splash of color.

Planted in beds around and beneath trees, the colors you select can mirror or complement the seasonal color of the leaves overhead. Above all, the mums can provide a dramatic climax for your landscape before the arrival of winter.

However, before you run off to your local supermarket to pick up your bounty of mums, you should consider a few important details. Most important of all, be sure to select hardy garden mums, not the foil-wrapped, potted florist mums. The mums commonly given as housewarming gifts are probably not winter hardy, and also tend to become quite tall, and will provide few blooms beyond the care and feeding of a greenhouse manager.

Instead, turn to a reputable garden center, where the mums are already somewhat acclimated to cooler temperatures, and where the plants were initially bred for use as perennials. Seek advice from a staff horticulturist if you are uncertain about your selection.

You will want to ensure that your mums will receive about six hours of sun, and should be planted in organically-rich, well-drained soil. Consider improving your soil by adding compost and prepare the planting bed eight to 12 inches deep.

After planting, water the mums thoroughly and water weekly thereafter, carefully avoiding wetting the foliage which can cause mildew. After the flowers have faded, snip off spent blooms and mulch the bed with shredded leaves or shredded hardwood mulch about three inches thick.

Keep in mind that there may be some losses if the winter months are especially harsh. Generally, spring-planted mums have a better survival rate than those planted in fall, but proper care can make a significant difference.

In early spring, pull back the mulch to allow new shoots to emerge and prune back old stems to the ground. After plants start growing fully, pinch back about four inches of growth every three to four weeks until July to encourage bushy growth, a full head of flowers, and an autumnal blooming period.

Every other spring, starting in about two years, divide your mums by digging up the entire plant, then use a sharp knife to separate well-rooted outer pieces from the original plant. Space out and replant the new pieces, and send the old woody core to the compost pile.

Interestingly, you will find that chrysanthemums seldom receive the recognition they deserve. For example, Preakness fans think they are seeing the winning horse and rider presented with a blanket of Black-eyed Susans. Not so! Those flowers are actually mums, substituted for the summer-blooming Maryland state flower.

A rose by any other name? You will also find that there are few roses adorning those colorful floats in the Rose Bowl Parade in Pasadena. Instead, delighted viewers are enjoying a kaleidoscope of mum blossoms and petals. But mums the word on that!

For more information on growing and appreciating mums, turn to the National Chrysanthemum Society and their website: www.mums.org.

Copyright 2009, Joseph M. Keyser

Monday, September 07, 2009

Orchid Cactus: A Plant With Pedigree (and Pizzazz)

For those of us with a drop or two of chlorophyll in our veins, propagating and sharing plants with friends and neighbors is second nature. You might think of it as hand-me-down horticulture.

One of the most bizarre and entrancing pass-along plants in my personal collection is the Orchid Cactus (Epiphyllum oxypetalum), often erroneously called “Night Blooming Cereus” or “Queen of the Night.” The latter names represent plants botanically known as Selenicereus, and offer fragrant flowers very similar in appearance and nocturnal blooming habit to the Orchid Cactus, but with the unpleasant added feature of spiny, forbidding stems, often found in many desert cacti.

The Orchid Cactus currently sprawling throughout my office is far more tropical in appearance, with extremely long, fleshy “leaves,” which are actually flattened stems, similar in appearance to a giant Christmas cactus. My companion started out as a several-inch long cutting which grew to almost five feet in height and width in just one summer. Today, after a recent severe pruning, it perches atop a bookcase, spreading out a host of improbably long, wavy fingers which menace unwary visitors.

The simple truth is that my treasured Epiphyllum is weird looking. So weird, in fact, that some coworkers have nicknamed it Audrey II, inspired by the man-eating alien in “Little Shop of Horrors.” Fortunately, this specimen has no appetite for flesh – or much of anything else.

During the winter months it will survive handsomely with no fertilizer and a simple sip of water once every several weeks, making it an extremely easy plant to cultivate indoors, especially for people who routinely kill other, more sensitive houseplants.

As its name implies, the Orchid Cactus shares a kinship with the spectacular orchids and bromeliads which like to show off amid the steamy jungles of Central and South America. Like those species, it can be found tucked into mossy, compost-filled nooks and branch angles of trees, sending out aerial roots for support and nutrients.

Its proper botanical name, Epiphyllum, means on- or upon-the-leaf, referring to the plant’s production of flowers along the margins of its flattened stems. And what flowers they are!

Orchid Cactus fanciers are generally more than willing to overlook the gawky, expansive nature of the plant if only to enjoy a single bloom once each year, although more mature plants can produce up to five flowers at a time. To add to the drama, the Epiphyllum blossom opens only at night, usually soon after sundown in mid- to late summer, taking several thrilling hours to open completely – and then close again forever.

The nocturnal performance features a creamy white alien abstraction, often up to eight inches in diameter, complete with rose-colored “tendrils” or tepals, pale green stamens and large buttery-yellow lobes. The blossom exudes a warm, somewhat musky aroma easily capable of filling an entire house until sunrise.

The whole affair is extremely sensual, from the anticipation inspired by the bud as it swells like a milky balloon, to the slow motion fan dance of the flower opening, releasing its rather indefinable fragrance, and then finally closing.

Some Epiphyllum fans actually throw impromptu parties to celebrate this magical event, while the rest of us are content to watch the show with a glass of wine and soft candlelight.

One of the most interesting, although possibly apocryphal, tales surrounding the plant comes from my friend, the late garden writer and editor Kathleen Fisher, who also potted up the cutting which became Audrey II.

Kathy was scheduled to attend a Garden Writers Conference in Philadelphia at the same time her Epiphyllum was slated to bloom. Without hesitation, Kathy packed up her unwieldy companion, secured it in her van, and drove to the conference. There are subsequent rumors of a late night soiree, bottles of Pinot Grigio, and a steady stream of garden writers making a pilgrimage to Kathy’s hotel room to enjoy the botanical spectacle. But those are only rumors -- maybe.

Kathy’s plant is itself an offshoot from a sizable plant owned by David Ellis, editor of The American Gardener, and is furthermore the progeny of a living room-sized plant nurtured by a neighbor of David’s, a German goldsmith who escaped the Holocaust. The plant in my office, which normally occupies a respectable portion of my rooftop garden, has subsequently been propagated and shared with other friends.

In fact, in exchange for one rooted cutting, a coworker provided me with a plant from his native India coincidentally called “Queen of the Night,” another fragrant nocturnal bloomer.

The unique history and pedigree of these hand-me-down plants seems to keep growing as quickly as the plants themselves, making these green specimens interesting from both a human and a horticultural perspective, and as equally endearing for the personal connections they inspire.

Copyright 2009, Joseph M. Keyser

Sunday, September 06, 2009

Composting With Pallets

Wooden shipping pallets are easily recycled into large, heavy-duty compost bins. Pallets are available for free from many area businesses, assemble in minutes, and with them you can produce rich humus, mulch and compost year after year. Here's how:

A Simple Pallet Bin

Obtain five pallets with narrow spaces between slats (1/2" - 1") and of uniform size. Many pallets measure 40" by 48" and will form a 48 cubic foot capacity bin. Pick up pallets from loading docks, freight companies, hardware stores, product wholesalers, nurseries and garden centers. Each year, American businesses send more than 300 million pallets to landfills and incinerators -- there are always plenty around for free. Good places to check are print shops, tire wholesalers, even central post office facilities who handle bulk mail.

To begin, place one pallet (slat-side up) on level ground. This pallet is the bottom of your bin and will allow for good drainage and aeration by keeping yard trimmings above the ground. Properly drained and aerated compost decomposes quickly and without odors.

Arrange the remaining pallets upright around each side of the base to form a box, short (40") sides up. Use spare wire, coathangers, or nylon rope to fasten the pallets together. Join pallets at each corner, lashing both the top and bottom. You can gain access to your compost pile by unfastening one side of a pallet and swinging it out like a hinged door.

Multi-Bin Units

Large properties and institutions like schools and churches may require a larger compost bin system to accommodate their materials. And gardeners looking for quick compost may prefer a multi-bin system to make turning materials easier.

First, construct a single bin as described above. Then expand your compost system by setting another pallet to the right of the base of your existing bin, and adjoining it. Form another box with three additional pallets to form the door and sides of the new bin. The two bins will share one side. Additional "bins" can be added-on using just four pallets at a time.

Two-bin systems allow easy turning of materials by transferring decomposing trimmings from one side to the other. Three-bin systems are favored by aggressive composters, with one bin used for newer materials, which are "turned" or transferred into the second bin after several weeks (or months), and later into the final "curing" bin for several weeks or months, prior to use. Churches and schools frequently construct three, four, or more bin systems to handle materials.


Lifespan and Maintenance

Pallet bin sides generally last from four to six years, depending on the level of active use. Bases last one to two years and need to be replaced. Just drop another fresh pallet over the old base after removing any compost still in the bin -- keep the new base as level as possible. The decomposing pallet will eventually turn to compost. Check corner lashing periodically and replace every several years, or as needed.

Piles and Pallets and Bins

Some composters prefer to use a free standing pile or "heap." Even this simple method of composting can be enhanced by using pallets to improve drainage and aeration. Use a pallet as the base of your compost "heap," rather than the layer of twigs or brush that are traditionally recommended. This smooth, even base will permit materials to be turned much more easily.

To create a pallet base, use a pallet with narrow 1/2" spaces between slats. If a pallet with narrow spaces is not available, try stapling or tacking a layer of hardware cloth to the top of the pallet to keep material from falling through the spaces. Two adjacent pallets on the ground create a handy work area for easy turning.

Homeowners who already have one of many commercially available compost bins can also improve good drainage and aeration. Simply set your open-base bin atop a wooden pallet. A layer of brush is now no longer required, thereby expanding you prefabricated unit's capacity.

Copyright 2009, Joseph M. Keyser

Wednesday, September 02, 2009

Versatile Viburnums for a Vibrant Landscape

Gardeners in the temperate zones of North America can select from hundreds of small trees and shrubs which will readily flourish in our climate. However, among all the choices there are only a handful of “must-have” species, with viburnum at the very top of that fairly short list.

There are approximately 200 species of viburnum worldwide, with more than 120 species in North America alone. Locally, in the Mid Atlantic region, our native landscape offers several absolutely dazzling specimens of viburnum that are suitable for almost every yard and situation, including Mapleleaf, Arrowwood, Possumhaw, and Blackhaw Viburnum (Viburnum acerifolium, V. dentatum, V. nudum, and V. prunifolium).

Michael Dirr at the University of Georgia writes in his landmark Manual of Woody Landscape Plants: “A garden without a viburnum is like life without music and art.” Dirr’s sentiment simply reflects the fact that it is difficult not to fall in love with viburnum. After all, we are talking about a species which is drought-tolerant and capable of handling dry soils, while it also thrives in moist, sometimes wet conditions.

The viburnum cited above will shine in either full sun of partial shade, making them ideal as either specimen plantings, or tucked in among other shrubs in a woodland garden.

Like most members of the Caprifoliaceae (honeysuckle) family, they are virtually pest-free and tolerant of pollution and harsh urban conditions. They can be trimmed and shaped to form an elegant privacy screen or hedge, or left alone to spread or “naturalize” across a wild, informal landscape.

But these noteworthy considerations are only horticultural nuts and bolts. Viburnums are easy to love because they are simply lovely.

Our native species all feature small white or creamy-white flowers appearing in flat-topped clusters or cymes roughly three or more inches wide. Actually, yellow stamens glowing against the white petals create the creamy color in both the Mapleleaf and Arrowwood shrubs. Some closely related viburnum species are even credited with pink or rosy blooms. The flowers typically appear in April through May, with each inflorescence lasting about two weeks.

But the show does not end in spring. While the flowering activity is somewhat reminiscent of our native dogwoods, the autumn foliage encore puts Cornus florida to shame. Depending on the species and growing conditions, fall leaf colors range from chartreuse and yellow, to orange, pink, red, burgundy and deepest purple. Moreover, the flowers will form drupes or berry-like fruits in attractive clusters from late summer through fall, which might last into winter, depending on avian appetites. The drupes range in color from a delicate porcelain-blue to purple and black.

Naturally, each of our featured viburnum have unique characteristics worth noting. For example, Mapleleaf Viburnum is decidedly a small multi-stemmed shrub, generally growing at a medium rate to between three and six feet high, with about the same spread or width. The species is known for its suckering ability, whereby shoots sprouting from the shrub’s base help it spread into a dense clump.

In fact, you might well consider planting a Mapleleaf for a hedge rather than turning to invasive species like privet, burning bush, or thorny barberry. Mapleleaf handles pruning easily, and can be kept in-bounds by mowing over tender suckers which might pop up in turf areas. This species can be easily propagated from cuttings taken between June and July. Buy just a couple of containerized plants and you can have a nursery-full in about a year.

Arrowwood is much like a big brother to Mapleleaf, sharing many of the former’s growth habits, although it can reach between eight and 13-feet in height, with branches arching out up between ten to 15-feet. Arrowwood also tends to grow in masses, making it another contender for a native hedgerow or screen.

Interestingly, many gardeners like to prune Arrowwood back to a single leader, encouraging it to behave more like a small specimen tree. Certainly its flowers, fruits, and autumn color establish it as a substitute for dogwoods, which are now under attack by fungal foes and insect-borers, and a fit companion for other woodland natives like Amelanchier and redbud.

Like all viburnum, Arrowwood is a phenomenal addition to any backyard wildlife habitat. However, as the shrub is “self-incompatible,” meaning that it cannot pollinate itself, you should plant at least several different specimens to ensure a dramatic and abundant display of fruit. The cedar waxwings, cardinals, and brown thrashers will thank you with a chorus of songs and whistles.

Arrowwood is also easily rooted, allowing you to propagate an entire shrub border from its ample supply of stout suckers. Indeed, the shoots sent up from the base of the shrub were so prized by Native Americans that they used them to make arrow shafts, from which this viburnum’s common name arises.

Possumhaw, also called Smooth Witherod, grows somewhat larger than Arrowwood, up to 20 feet, and can be decidedly more tree-like, featuring a rounded crown with a considerable spread. It also features long-stemmed, flat clusters of small, creamy white flowers which first start appearing in May.

The common name for this species denotes the popularity of its long, dangling clusters of fruits among opossums, although other small mammals such as squirrels, rabbits and chipmunks, as well as songbirds, make quite a feast from the half-inch long oval drupes, which start out green, quickly turning pink, and finally ripening to a dark blue or purplish-black and lasting throughout winter.

The species other common name, “withe-rod,” reflects that the tree’s smooth grayish-brown twigs are strong and flexible, and, in fact, were often twisted together to form a rope to gather together sheaves of wheat.

One of the more lovely features of Possumhaw are its waxy, dark green leaves, perhaps the glossiest of any viburnum, which turn to a rich cinnabar (cinnamon to scarlet) in autumn. ‘Winterthur’ is probably the most popular cultivar currently and commonly found, having a more compact form, growing to about six feet, with aromatic flowers in spring and brilliant red fall color.

The last selection is the largest and most versatile. Blackhaw is the most like a small tree, growing up to 21-feet or somewhat more. Although it also produces suckers and can be multi-stemmed, for the most part it is a slow-growing tree with a rounded crown and a thirst for moist and wet soils.

Blackhaw is the best choice for a stand-alone ornamental, and is a superior substitute for invasive and troublesome species such as Russian and Autumn Olive, Bradford Pear, and many of the other popular Asian pears and ornamental cherries.

Blackhaw can be also be used as a tall deciduous screen or hedge, much like hawthorns, to which this species is often compared. It takes well to transplanting, which is helpful should you need to thin out a too-dense hedgerow.

From dry upland slopes to soggy floodplains, viburnum can provide privacy, habitat, and year-round beauty, adapting to most every type of soil and exposure.

Copyright 2009, Joseph M. Keyser

Tuesday, September 01, 2009

Native Grasses for a Naturally Elegant Landscape

The introduction of ornamental grasses to the American landscape is one of the defining moments in modern garden design. These grasses, planted in clumps or large masses, recall elements of the nation's vanishing prairie, while adding sophistication and panache to even the most groomed garden.

Regrettably, many of the grasses frequently used, especially those with ostrich feather-like plumes or stylish zebra-stripes, are both exotic and invasive, especially when planted near open fields, and can pose serious problems for our local ecosystem. For a more habitat-friendly approach, gardeners can and should turn to the abundant inventory of native grasses which will provide the same elements of year-round color, texture, and graceful, swaying motion.

One of the most widely available and popularly used native grasses is big bluestem (Andropogon gerardi), or "turkey foot," affectionately dubbed "monarch of the prairie" by some horticultural boosters. Big bluestem was the dominant species of grass which formed our fabled tall grass prairies, as well as the sod used by homesteaders (sodbusters) and pioneers to build sod huts.

Sod dwellings don't show up very much in most parts of the country, but big bluestem does, both in habitat restoration plantings and in backyards, where they are frequently clumped in mulched planting beds or "grass islands" which decoratively float atop a trimmed lawn. Formal plantings also use these seemingly untamed specimens to dramatically frame a front entrance or serve as sentinels at the end of a driveway.

Big bluestem can reach up to ten feet in height and prefers full sun, although it is tolerant of partial shade and either moist heavy, or sandy, drier soils. Like most native grasses, it prefers being left alone, and fertilizing or unnecessary watering will simply lead to floppy growth. This is a tough plant, let it prove itself! The plant's common name comes honestly from its vertical height and the subtle blue tint of the stem. And while the leaves remain bluish-green during much of the year, autumn frosts help transform that foliage to a mellow bronze or copper shade which will last throughout the winter.

The plant's less common name originates with the three-fingered prongs or "rames" of the purplish-blue seed head, which resembles a turkey's foot, and which begin forming in late summer, and provide seed to a host of migratory and native songbirds through early winter.

A close cousin to big bluestem is little bluestem (Schizachyrium scoparium), which shares many of its relation's best characteristics, although it is best planted in masses for best effect, especially considering the beauty of watching a whole miniature sea of grass swaying their silver seed heads in the breeze.

Also a sun lover, the fluffy, tufts of this species mature on a clump-forming plant destined to stay between two and three feet in height. Like most sod-forming grasses, little bluestem does most of its growing underground, sending roots eight feet deep, which makes it equally adaptable to periods of drought or flooding. These qualities make it ideal for erosion control and mower-free hillside stabilization. It is also salt-tolerant, which nominates it for use as en edging plant along sidewalks and curbs.

For gardeners looking for a mid-size grass, there are few more noteworthy than switchgrass (Panicum virgatum), a full sun plant that can adapt to partial shade and either moist or dry conditions. It is wonderfully useful as either a specimen plant, or in small, bush-like clusters, or even planted en masse. Maryland-based garden writer Carole Ottesen favorably compares these massed plantings to a field of wheat. Staying somewhat between three and eight feet tall, depending on soil conditions, the rich green foliage slowly takes on a buttery-cream complexion in fall.

Another attractive and adaptable option for yards with light to moderate shade is bottlebrush grass (Hystrix patula). This species is modest in most respects, averaging only two to five feet in height, and producing only moderately attractive, medium-green foliage, turning straw-colored in autumn. However, the bristly seed heads are quite remarkable, resembling by turns an actual bottlebrush or the long quills of a hedgehog, from which the genus name Hystrix (porcupine) is taken.

And while almost all grass seed heads make for wonderful dried or cut flower arrangements, bottlebrush flowers are incomparable when placed in a window for a striking bit of backlighting.

A close rival for flower arranging - and garden use - is northern sea oats, or river oats (Uniola latifolia), a low-growing, shade-tolerant species whose 30 inch height makes for an excellent ground cover or placed along a perennial boarder, where visitors can fully appreciate its drooping clusters of oat-shaped seeds and rusty-orange fall foliage.

In the same vein, broom sedge (Andropogon virginicus), another cousin of the bluestems, works well as a ground cover or for erosion control, with bluish-green clumps keeping to about 20 to 30 inches in height, with another foot or two more for its inflorescence. Like many of our favorite native grasses, autumn brings on a rich orange color, with seeds for meadow birds and the occasional migrant.

Clearly, the range and application of native grasses is limited only by the size of the garden bed or landscape, and its desired use. Taller and medium sized grasses can serve as hedges or screens, to hide unattractive fences or foundations, or more properly as a backdrop for other garden plantings. Typically, these individuals are best spaced two to three feet apart.

Medium to low-growing specimens often work best in larger groupings, planted one to two feet apart, and are used successfully as ground covers, especially those shade-loving or shade-tolerant grasses which can fill in nicely under mature trees with open scaffolding or along the edge of a wooded area.

A key to making the most of native ornamental grasses is combining them with other flowering natives, or non-invasive annuals and perennials, which will compliment the structure and form of the grasses, while providing color during the spring and summer, as well as a low-flowing, spreading appearance.

Lastly, to truly transform your grass islands or prairie shrubbery into an outdoor bouquet, try to marry the bronze, orange, and copper hues of fall foliage, to say nothing of their crimson-purple flowers and rusty-brown seed heads, with the floral display of late-summer and autumn show-offs like joe-pye weed, sunflowers, asters, ironweed, and goldenrods.

With any luck, the memory of your grassy garden, along with vases filled with bold sprays of seed heads, will keep you smiling all winter long.

Copyright 2009, Joseph M. Keyser