Bamboozled by Bambusa

A common axiom in gardening is putting the right plant in the right place. Where bamboo is concerned, most people think that the only appropriate location is somewhere on the far side of hell. Bamboo is cherished and ardently defended as a vigorous landscape screen by some, although it is usually cursed as an invasive, unstoppable menace by most others, especially irate neighbors who find spikes and spears shooting up in their lawn and garden beds.

There are more than 750 species of bamboo plants which have been introduced to North America from Asia, the Caribbean, and Latin America. Most of these woody grasses (yes, they are actually grasses!) fall within the genera Bambusa, Pseudosasa, and Phyllostachys, and are renowned for growing upwards of 16 to 40 feet, with a cane or “culm” diameter ranging from one to six inches. Many also experience a general die-back after about a dozen years, usually after flowering, which will leave a dead, yellowed bamboo jungle, until new growth repopulates the grove.

Some species are considered “clumping,” which are generally well-behaved, while the more insidious specimens are called “running bamboos,” which will swiftly produce an impenetrable and monocultural thicket as they exert their own manifest destiny. Among the most commonly sold, planted, and (ultimately) loathed of runners is Golden Bamboo (Phyllostachys aurea).

These exotic invasive bamboos have caused feuds just shy of the infamous Hatfield and McCoy dust-up. Lawsuits have been filed, bulldozers mobilized, and concrete barriers poured. And yet, for all that, people looking to screen their yards from neighbors continue to plant running bamboos, especially in narrow spaces between properties or along fence lines.

Happily, there are attractive and non-invasive alternatives to bamboo blight, but first we should address how best to control and eradicate these invaders.

To keep bamboos from running, a rhizome barrier should be used. Bamboos very seldom produce seeds, and use rhizomes, or horizontal underground roots, to spread outward. To stop this march, a barrier two-three feet deep is essential, with about two inches rising above the soil surface. Slant the barrier outward near the top to ensure that rhizomes hitting your blockade will grow upward, and not down and eventually under the barrier. Keep an eye out and cut off any roots that attempt to grow over the top. Barriers can be made from metal or concrete, although heavy 60 mil plastic is the most readily available and affordable.

Clumps of bamboo can also be dug out, as the roots are actually quite shallow. Be sure to remove any and all pieces of the rootstock, including wayward rhizomes, and keep an eye out for future incursions.

A somewhat easier approach is to cut bamboo shoots as close to the ground as possible, and thereafter snip or mow down any new shoots or pesky regrowth. Eventually, you will starve the rootstock and the plant will die, although you will need to patrol the area on a regular basis for a year or so. This technique is best used on bamboo entering your yard from a neighboring property. In fact, some homeowners simply mow down any shoots in their lawns when they cut their grass, and have seen thumb-thick shoots eventually replaced by pencil-thin sprouts, just before they disappear altogether.

For quicker, more thorough results, Jan Ferrigan, an invasive plant program manager in Virginia, recommends cutting down bamboo shoots and applying Roundup or a similar glyphosate herbicide directly inside the now-open stem, and painting the outer surface of the culm. Jan suggests carefully using the herbicide at a 25 percent concentrated solution, not the typically diluted two percent used for routine spraying. And fall is the usually recommended time for application.

Naturally, the best solution is not to plant exotic bamboos at all. And the finest alternative is, not surprisingly, a native bamboo. Generally called canebrake bamboo (Arundinaria gigantea), or southern cane, this species used to cover enormous stretches of riparian “bottom land” from the mid-Atlantic to the Midwest prairies, down through the southeast, and along the Gulf states. Amazingly, before European colonization, native Americans lived among canebrake groves several miles in width, running up to 100 miles in length. Today, there are only scattered patches of these lush thickets.

Homeowners looking for a tall, dense, yet elegant, living fence need look no further. Canebrake can reach 12 to 18 feet or more, with half- to three-quarter inch canes and medium to dark green foliage year-round. However, when shopping around, don’t confuse this species with switch cane (A. tecta), which is smaller, low growing, and more suited as a groundcover plant. And while very few garden centers and nurseries seem to carry canebrake, there are numerous sources online and through mail-order catalogs, with prices ranging from 15 to 25 dollars for one and two gallon containers.

Not interested in bamboo at all? Consider arborvitae (Thuja occidentalis) as an alternate evergreen screen. The cultivar Emerald Green is probably the most popular of standard arborvitae, growing 15-20 feet, with a spread of four-six feet. Its lustrous gem-green foliage is tolerant of cold winters and hot summers, although, as a native of the northeast, it would prefer to be watered during dry periods, and mulched three to four inches deep to retain soil moisture.

Emerald Green can be pruned if or as desired in early spring, and is often considered superior to the much overused Leyland cypress, which could also work as a screen, although it can reach 60 feet and would require substantial pruning to achieve the same effect. Other desirable cultivars include both ‘Nigra,’ which remains dark green even through the winter, featuring a pyramidal form reaching 15-25 feet and five-eight feet wide, and ‘Pyramidalis,’ with softer, bright green needles, growing to 15 feet with a four foot spread.

Another clear winner is Irish juniper (Juniperus communis ‘Hibernica’) with bluish-green foliage, and a columnar form reaching 10-12 feet. This juniper is drought tolerant, with dense upright branches. Some nurseries indicate that it can reach 15 feet with only a narrow two-four foot spread.

There are also numerous species of yews suitable for narrow space screening. All are able to handle heavy pruning and shaping, and contrast their dark green foliage with bright, fleshy red or yellowish-red berries, called arils.

Perhaps most prized of all is Irish yew (Taxus baccata ‘Fastigiata’), which is actually an English or common yew, easily growing from 15-30 feet tall, with a four-eight foot spread. [It is the most commonly grown species in Europe, and has been in use for well over 200 years.] The needles are a striking blackish-green, although other cultivars, such as ‘Fastigiata Aurea,’ while similar in form, actually feature golden foliage on its new spring growth.

Japanese Yews (Taxus cuspidata) generally tend to have a broader spread and lower growth habit, and often quite a slow growth rate. However, cross Japanese and English yews and you’ll find a hybrid (Taxus x media) showcasing some of the best assets of each parent. Many of the outstanding cultivars for living screens were developed or discovered on my native Long Island, including several by famed nurseryman Henry Hicks. The specimen bearing his name, Hicks yew (Taxus x media ‘Hicksii’), is columnar in form, 12-20 feet high, and six-ten feet across, with glossy needles, deep green on top and a pale green underneath.

Lastly, Eastern hemlock (Tsuga canadenensis) has long be valued for its light, airy needles and graceful branches, which readily accommodate heavy pruning to create a lush, dense hedge. Left on its own, however, the tree will reach 60 feet with wider spaced branches.

Copyright 2014, Joseph M. Keyser

Don't Get Bamboozled!

A common axiom in gardening is putting the right plant in the right place. Where bamboo is concerned, most people think that the only appropriate location is somewhere on the far side of hell. Bamboo is cherished and ardently defended as a vigorous landscape screen by some, although it is usually cursed as an invasive, unstoppable menace by most others, especially irate neighbors who find spikes and spears shooting up in their lawn and garden beds.

There are more than 750 species of bamboo plants which have been introduced to North America from Asia, the Caribbean, and Latin America. Most of these woody grasses (yes, they are actually grasses!) fall within the genera Bambusa, Pseudosasa, and Phyllostachys, and are renowned for growing upwards of 16 to 40 feet, with a cane or “culm” diameter ranging from one to six inches. Many also experience a general die-back after about a dozen years, usually after flowering, which will leave a dead, yellowed bamboo jungle, until new growth repopulates the grove.

Some species are considered “clumping,” which are generally well-behaved, while the more insidious specimens are called “running bamboos,” which will swiftly produce an impenetrable and monocultural thicket as they exert their own manifest destiny. Among the most commonly sold, planted, and (ultimately) loathed of runners is Golden Bamboo (Phyllostachys aurea).

These exotic invasive bamboos have caused feuds just shy of the infamous Hatfield and McCoy dust-up. Lawsuits have been filed, bulldozers mobilized, and concrete barriers poured. And yet, for all that, people looking to screen their yards from neighbors continue to plant running bamboos, especially in narrow spaces between properties or along fence lines.

Happily, there are attractive and non-invasive alternatives to bamboo blight, but first we should address how best to control and eradicate these invaders.

To keep bamboos from running, a rhizome barrier should be used. Bamboos very seldom produce seeds, and use rhizomes, or horizontal underground roots, to spread outward. To stop this march, a barrier two-three feet deep is essential, with about two inches rising above the soil surface. Slant the barrier outward near the top to ensure that rhizomes hitting your blockade will grow upward, and not down and eventually under the barrier. Keep an eye out and cut off any roots that attempt to grow over the top. Barriers can be made from metal or concrete, although heavy 60 mil plastic is the most readily available and affordable.

Clumps of bamboo can also be dug out, as the roots are actually quite shallow. Be sure to remove any and all pieces of the rootstock, including wayward rhizomes, and keep an eye out for future incursions.

A somewhat easier approach is to cut bamboo shoots as close to the ground as possible, and thereafter snip or mow down any new shoots or pesky regrowth. Eventually, you will starve the rootstock and the plant will die, although you will need to patrol the area on a regular basis for a year or so. This technique is best used on bamboo entering your yard from a neighboring property. In fact, some homeowners simply mow down any shoots in their lawns when they cut their grass, and have seen thumb-thick shoots eventually replaced by pencil-thin sprouts, just before they disappear altogether.

For quicker, more thorough results, Jan Ferrigan, an invasive plant program manager in Virginia, recommends cutting down bamboo shoots and applying Roundup or a similar glyphosate herbicide directly inside the now-open stem, and painting the outer surface of the culm. Jan suggests carefully using the herbicide at a 25 percent concentrated solution, not the typically diluted two percent used for routine spraying. And fall is the usually recommended time for application.

Naturally, the best solution is not to plant exotic bamboos at all. And the finest alternative is, not surprisingly, a native bamboo. Generally called canebrake bamboo (Arundinaria gigantea), or southern cane, this species used to cover enormous stretches of riparian “bottom land” from the mid-Atlantic to the Midwest prairies, down through the southeast, and along the Gulf states. Amazingly, before European colonization, native Americans lived among canebrake groves several miles in width, running up to 100 miles in length. Today, there are only scattered patches of these lush thickets.

Homeowners looking for a tall, dense, yet elegant, living fence need look no further. Canebrake can reach 12 to 18 feet or more, with half- to three-quarter inch canes and medium to dark green foliage year-round. However, when shopping around, don’t confuse this species with switch cane (A. tecta), which is smaller, low growing, and more suited as a groundcover plant. And while very few garden centers and nurseries seem to carry canebrake, there are numerous sources online and through mail-order catalogs, with prices ranging from 15 to 25 dollars for one and two gallon containers.

Not interested in bamboo at all? Consider arborvitae (Thuja occidentalis) as an alternate evergreen screen. The cultivar Emerald Green is probably the most popular of standard arborvitae, growing 15-20 feet, with a spread of four-six feet. Its lustrous gem-green foliage is tolerant of cold winters and hot summers, although, as a native of the northeast, it would prefer to be watered during dry periods, and mulched three to four inches deep to retain soil moisture.

Emerald Green can be pruned if or as desired in early spring, and is often considered superior to the much overused Leyland cypress, which could also work as a screen, although it can reach 60 feet and would require substantial pruning to achieve the same effect. Other desirable cultivars include both ‘Nigra,’ which remains dark green even through the winter, featuring a pyramidal form reaching 15-25 feet and five-eight feet wide, and ‘Pyramidalis,’ with softer, bright green needles, growing to 15 feet with a four foot spread.

Another clear winner is Irish juniper (Juniperus communis ‘Hibernica’) with bluish-green foliage, and a columnar form reaching 10-12 feet. This juniper is drought tolerant, with dense upright branches. Some nurseries indicate that it can reach 15 feet with only a narrow two-four foot spread.

There are also numerous species of yews suitable for narrow space screening. All are able to handle heavy pruning and shaping, and contrast their dark green foliage with bright, fleshy red or yellowish-red berries, called arils.

Perhaps most prized of all is Irish yew (Taxus baccata ‘Fastigiata’), which is actually an English or common yew, easily growing from 15-30 feet tall, with a four-eight foot spread. [It is the most commonly grown species in Europe, and has been in use for well over 200 years.] The needles are a striking blackish-green, although other cultivars, such as ‘Fastigiata Aurea,’ while similar in form, actually feature golden foliage on its new spring growth.

Japanese Yews (Taxus cuspidata) generally tend to have a broader spread and lower growth habit, and often quite a slow growth rate. However, cross Japanese and English yews and you’ll find a hybrid (Taxus x media) showcasing some of the best assets of each parent. Many of the outstanding cultivars for living screens were developed or discovered on my native Long Island, including several by famed nurseryman Henry Hicks. The specimen bearing his name, Hicks yew (Taxus x media ‘Hicksii’), is columnar in form, 12-20 feet high, and six-ten feet across, with glossy needles, deep green on top and a pale green underneath.

Lastly, Eastern hemlock (Tsuga canadenensis) has long be valued for its light, airy needles and graceful branches, which readily accommodate heavy pruning to create a lush, dense hedge. Left on its own, however, the tree will reach 60 feet with wider spaced branches.

Copyright 2011, Joseph M. Keyser

Don't Get Bamboozled!

A common axiom in gardening is putting the right plant in the right place. Where bamboo is concerned, most people think that the only appropriate location is somewhere on the far side of hell. Bamboo is cherished and ardently defended as a vigorous landscape screen by some, although it is usually cursed as an invasive, unstoppable menace by most others, especially irate neighbors who find spikes and spears shooting up in their lawn and garden beds.

There are more than 750 species of bamboo plants which have been introduced to North America from Asia, the Caribbean, and Latin America. Most of these woody grasses (yes, they are actually grasses!) fall within the genera Bambusa, Pseudosasa, and Phyllostachys, and are renowned for growing upwards of 16 to 40 feet, with a cane or “culm” diameter ranging from one to six inches. Many also experience a general die-back after about a dozen years, usually after flowering, which will leave a dead, yellowed bamboo jungle, until new growth repopulates the grove.

Some species are considered “clumping,” which are generally well-behaved, while the more insidious specimens are called “running bamboos,” which will swiftly produce an impenetrable and monocultural thicket as they exert their own manifest destiny. Among the most commonly sold, planted, and (ultimately) loathed of runners is Golden Bamboo (Phyllostachys aurea).

These exotic invasive bamboos have caused feuds just shy of the infamous Hatfield and McCoy dust-up. Lawsuits have been filed, bulldozers mobilized, and concrete barriers poured. And yet, for all that, people looking to screen their yards from neighbors continue to plant running bamboos, especially in narrow spaces between properties or along fence lines.

Happily, there are attractive and non-invasive alternatives to bamboo blight, but first we should address how best to control and eradicate these invaders.

To keep bamboos from running, a rhizome barrier should be used. Bamboos very seldom produce seeds, and use rhizomes, or horizontal underground roots, to spread outward. To stop this march, a barrier two-three feet deep is essential, with about two inches rising above the soil surface. Slant the barrier outward near the top to ensure that rhizomes hitting your blockade will grow upward, and not down and eventually under the barrier. Keep an eye out and cut off any roots that attempt to grow over the top. Barriers can be made from metal or concrete, although heavy 60 mil plastic is the most readily available and affordable.

Clumps of bamboo can also be dug out, as the roots are actually quite shallow. Be sure to remove any and all pieces of the rootstock, including wayward rhizomes, and keep an eye out for future incursions.

A somewhat easier approach is to cut bamboo shoots as close to the ground as possible, and thereafter snip or mow down any new shoots or pesky regrowth. Eventually, you will starve the rootstock and the plant will die, although you will need to patrol the area on a regular basis for a year or so. This technique is best used on bamboo entering your yard from a neighboring property. In fact, some homeowners simply mow down any shoots in their lawns when they cut their grass, and have seen thumb-thick shoots eventually replaced by pencil-thin sprouts, just before they disappear altogether.

For quicker, more thorough results, Jan Ferrigan, an invasive plant program manager in Virginia, recommends cutting down bamboo shoots and applying Roundup or a similar glyphosate herbicide directly inside the now-open stem, and painting the outer surface of the culm. Jan suggests carefully using the herbicide at a 25 percent concentrated solution, not the typically diluted two percent used for routine spraying. And fall is the usually recommended time for application.

Naturally, the best solution is not to plant exotic bamboos at all. And the finest alternative is, not surprisingly, a native bamboo. Generally called canebrake bamboo (Arundinaria gigantea), or southern cane, this species used to cover enormous stretches of riparian “bottom land” from the mid-Atlantic to the Midwest prairies, down through the southeast, and along the Gulf states. Amazingly, before European colonization, native Americans lived among canebrake groves several miles in width, running up to 100 miles in length. Today, there are only scattered patches of these lush thickets.

Homeowners looking for a tall, dense, yet elegant, living fence need look no further. Canebrake can reach 12 to 18 feet or more, with half- to three-quarter inch canes and medium to dark green foliage year-round. However, when shopping around, don’t confuse this species with switch cane (A. tecta), which is smaller, low growing, and more suited as a groundcover plant. And while very few garden centers and nurseries seem to carry canebrake, there are numerous sources online and through mail-order catalogs, with prices ranging from 15 to 25 dollars for one and two gallon containers.

Not interested in bamboo at all? Consider arborvitae (Thuja occidentalis) as an alternate evergreen screen. The cultivar Emerald Green is probably the most popular of standard arborvitae, growing 15-20 feet, with a spread of four-six feet. Its lustrous gem-green foliage is tolerant of cold winters and hot summers, although, as a native of the northeast, it would prefer to be watered during dry periods, and mulched three to four inches deep to retain soil moisture.

Emerald Green can be pruned if or as desired in early spring, and is often considered superior to the much overused Leyland cypress, which could also work as a screen, although it can reach 60 feet and would require substantial pruning to achieve the same effect. Other desirable cultivars include both ‘Nigra,’ which remains dark green even through the winter, featuring a pyramidal form reaching 15-25 feet and five-eight feet wide, and ‘Pyramidalis,’ with softer, bright green needles, growing to 15 feet with a four foot spread.

Another clear winner is Irish juniper (Juniperus communis ‘Hibernica’) with bluish-green foliage, and a columnar form reaching 10-12 feet. This juniper is drought tolerant, with dense upright branches. Some nurseries indicate that it can reach 15 feet with only a narrow two-four foot spread.

There are also numerous species of yews suitable for narrow space screening. All are able to handle heavy pruning and shaping, and contrast their dark green foliage with bright, fleshy red or yellowish-red berries, called arils.

Perhaps most prized of all is Irish yew (Taxus baccata ‘Fastigiata’), which is actually an English or common yew, easily growing from 15-30 feet tall, with a four-eight foot spread. [It is the most commonly grown species in Europe, and has been in use for well over 200 years.] The needles are a striking blackish-green, although other cultivars, such as ‘Fastigiata Aurea,’ while similar in form, actually feature golden foliage on its new spring growth.

Japanese Yews (Taxus cuspidata) generally tend to have a broader spread and lower growth habit, and often quite a slow growth rate. However, cross Japanese and English yews and you’ll find a hybrid (Taxus x media) showcasing some of the best assets of each parent. Many of the outstanding cultivars for living screens were developed or discovered on my native Long Island, including several by famed nurseryman Henry Hicks. The specimen bearing his name, Hicks yew (Taxus x media ‘Hicksii’), is columnar in form, 12-20 feet high, and six-ten feet across, with glossy needles, deep green on top and a pale green underneath.

Lastly, Eastern hemlock (Tsuga canadenensis) has long be valued for its light, airy needles and graceful branches, which readily accommodate heavy pruning to create a lush, dense hedge. Left on its own, however, the tree will reach 60 feet with wider spaced branches.

Copyright 2010, Joseph M. Keyser

Smart Solutions for Steep, Sunny Slopes

A steep, sunny slope in your landscape can be a real challenge, especially if you’re trying to manage that area as a lawn. The slope itself makes mowing difficult -- if not outright dangerous -- and it is difficult to keep the turf green, as most water simply flows downhill, leaving the hillsides brown and barren. A proper solution should really turn this landscaping liability into an attractive asset.

There are a number of suitable solutions, but most are fairly expensive, such as designing and installing retaining walls, along with extensive replanting. Moreover, if the angle of your slope exceeds 20 degrees, you may need to engage a soils engineer or landscape architect. There might even be heavy equipment in your future. Ka-ching!

A simpler fix, ideal for the do-it-yourselfer, would simply call for replacing turf grass with a low maintenance ground cover. Keep in mind that many of the most popular ground covers are actually invasive weeds, and can often create management headaches in their own right. These include Five-leaf Akebia, Japanese Barberry, Crown Vetch, Wintercreeper (Euonymus fortunei), and English Ivy, which can often bake in full sun. Moreover, the “wild” nature of such plants makes mulching difficult, and can lead to even more weeds taking hold. So much for low maintenance!

For my money – or yours – one of the best solutions is an evergreen groundcover: something with an obedient and predictable growth habit, and an attractive year-round appearance. Think juniper.

There are literally scores of procumbent juniper species, and similar conifers, which will happily bask in the hottest sun, stretching across your hillside over the course of several years, all providing excellent erosion control and weed suppression, especially when combined with diligent annual mulching, and saving you the need to combine mowing with mountaineering. And these hardy plants are almost always drought-tolerant, helping to conserve water, while requiring no fertilizing.

Among the most common and popular junipers used as groundcovers are the creeping junipers (Juniperus horizontalis), slow to medium-growing shrubs, which form dense, aromatic mats between 12 and 18 inches in height, extending trailing branches from four to eight feet across, depending on the cultivar. Most feature either soft or prickly scale-like bluish-green foliage, which often “bronzes” once hit by cold winter temperatures. But don’t worry, they will “green up” again in the spring as air and soil temperatures warm up.

Blue Rug or ‘Wiltoni’ is probably the most popular juniper sold. It hugs the ground at four to six inches, and provides coverage up to eight feet in diameter. Blue Rug is drought-tolerant and thrives in conditions ranging from coastal Maine to the mountains of Georgia.

Other popular cultivars offer a Mardi Gras parade of colors and shades, from gold to green to purple, in a range of heights. Favorites include ‘Bar Harbor,’ which is similar to Blue Rug, although more colorful in winter, the bright green ‘Emerald Spreader,’ four-to-six inch tall ‘Prince of Wales,’ gold-variegated ‘Mother Lode,’ and ‘Pancake,’ lowest of the low at two-to-three inches.

‘Blue Star’(J. squamata) is a taller, different species, featuring cool blue foliage, and a pyramidal growth habit. This selection will generally stay below two feet in height, but can reach three feet, with only a two to four foot spread. It would be especially useful under a retaining wall for terraces, or against a rock outcropping.

Not all junipers are groundcovers: some are actually full-grown trees, like our native Eastern Red Cedar, which reaches an impressive 30 feet. Others tend to be shrubs, useful as hedges, such as the Chinese Junipers (J. chinensis), which reach about six feet in height, although some can become small trees up to 20 feet. One notable exception is Sargent Juniper, a cultivar that hovers at about 18 to 24 inches with an eight to ten foot spread. Many landscapers turned off by a juniper’s tendency to turn bronze in winter prefer Sargent, as it keeps its grayish-blue color year-round.

Dwarf Japanese Garden Juniper (J. procumbens ‘Nana’), provides bluish-green foliage which turns a stunning purple-bronze in late fall and winter. Horticulturist Mitch Baker (my go-to guy) at American Plant in Bethesda, Maryland is enthusiastic about ‘Nana’s’ spray-like mounding habit, which provides an exciting departure from the flat mat-like appearance of many other species, and allowing for a level of dimension to your hillside.

Mitch also noted options beyond junipers, such as the confusingly-named Siberian Juniper (Microbiata decussata), which is also called either Russian Arborvitae or Siberian Carpet Cypress, due to the shape of its foliage. Siberian Juniper is fairly new on the market, but is quite versatile thanks to its tolerance for Siberian winters and partial (not full) shade, as well as average soil and dry conditions. This specimen’s feathery foliage stays within eight to 12 inches in height, with an above-average ten foot spread.

And “spread” is the name of the game with junipers and other ground covers. Obviously, the wider the area covered by the plant, the fewer plants you will need. Most junipers can be planted approximately six feet apart, although you should check – and do the math – before purchasing and planting. Larger container stock, about three gallons, will provide a vigorous root system, ideal for early season planting, and will get your hillside off to a fine start.

Costs can range from 15 to 35 dollars, depending on the cultivar, size, and source. Smaller containers will be less expensive, but might take years to fill in. Don’t make the mistake of buying a lot of smaller containers and planting them too close together to create a finished look. Overcrowding can lead to disease problems and might require substantial transplanting in just a few years. Remember, you want a low-maintenance landscape: plan and plant properly, according to your budget, and let time and patience do the rest.

Decide in advance if you want to address the entire hillside at once, or just tackle a portion at a time. For best results, smother the grass or weeds on the site with landscape fabric or cardboard and a three to six inch layer of shredded wood mulch. Shredded mulch will lock together in place, where nuggets or chips might be washed off. Be sure to stagger your planting holes so that plants can diffuse flow down the slope and prevent erosive gullies. Check your soil to see if it needs amending with compost – although most junipers are tolerant of relatively poor soils as long as they receive good drainage.

Copyright 2009, Joseph M. Keyser

Rhapsody in Blue

Gardening, at its best, is all about orchestration. Like any musical composition, a garden requires the proper arrangement of colors, textures, and form. But it also begs for a certain amount of experimentation. Why not follow a bit in Gershwin’s musical footsteps? His innovative jazz concerto stunned audiences by combining a range of musical traditions. You can likewise use your garden space to blend together a wide variety of otherwise unrelated plants.

Mix some fancy uptown perennials with the brassy tone of common annuals; introduce your native plants to some interesting exotics. The important thing is to pull all of these elements together. So, like Gershwin, why not start with a single color theme? A rhapsody of blue foliage and flowers!

One of the most pleasant discoveries about using blue (and related tones of purple and lavender) is that the color is not only peaceful, cool, and restful, but it also tricks the eye into making smaller spaces appear larger. This helps add depth to townhouse gardens or tight-fitting urban plots. A cramped-feeling corner can become an inviting retreat.

But even larger spaces can benefit from the blues. A barren yard can take on a special new dimension when planted with a stand of blue spruce trees and blue atlas cedars, perhaps interspersed with some dwarf blue spruce and creeping juniper (‘Blue Chip’), which also works well as a no-fuss, sun-loving groundcover. A rather modest investment will soon screen your yard from neighbors and create a calming sanctuary.

Open areas are prime candidates for blue garden beds. Using mulch in a sweeping, free form pattern, create one or more large mounded “islands” featuring fragrant, summer-flowering Chaste trees (Vitex agnus-castus), among which you can introduce tufts of little bluestem grasses (‘The Blues’), wild blue indigo, delphinium (‘Blue Bird’), columbine (‘Blue Shade’), an assortment of asters (New England ‘Purple Dome’ and pale blue Aster laevis, among others) cornflowers, perennial flax, blue gentian, purple sage (Salvia officinalis ‘Purpurea’), and gayfeather (Liatris spicata). As a dividend, you will enjoy noting that most of these species attract butterflies, who will add their own unique color to your garden.

While developing your planting pallette of blue and purple, it helps to include and intersperse plants with silver, gray-green, and white foliage, such as artemisia, dusty miller, and fuzzy lambs ears, which also send up blue flower spikes. The silver foliage provides a much-needed soft backdrop and subtly harmonizes the varied blue notes. In addition, to jazz up your cool blue theme, consider adding contrasting accents of bright yellow, gold, pink and red, in limited quantities.

Another striking planting bed can be created using groupings of butterfly bush, especially the deep purple of ‘Black Knight’ or the rich lavender of ‘African Queen.’ These inexpensive, medium to large-sized shrubs are butterfly magnets, although humans are also taken in by the honey-scented aroma. However, because butterfly bush is a non-native and can reseed rather easily, people living in natural and agricultural areas might want to avoid planting it, lest it become semi-invasive.


As many of the blue flowering plants tend to be discrete, it is often advisable to plant them in large, natural-looking “drifts,” rather than installing a single, lonely specimen. Breathtaking herbal displays can be designed along sunny walkways and borders using lavender, catmint, anise hyssop, Russian sage (Perovskia atriplicifolia), or borage, either alone or combined with one another.

Of course, shady borders and the edges of natural areas will also benefit from shades of blue, from our native Virginia bluebells and phlox species (creeping, wild blue, and fall phlox), to Iris versicolor and dwarf-crested iris, and on to the ever versatile forget-me-nots, which offer a low-flowing blanket of delicate blue in May and June.

Perhaps no genus of plants makes a better show in shady areas than the hostas. Often thought of as a smaller, clumping groundcover, like ‘Blue Moon,’ some species of hosta can actually reach three feet in height. Do not select plants for their flowers so much as their foliage, which can range from velvety smooth to stiff and corrugated. The leaves of ‘Blue Angel’ can create a shrub-like clump up to seven feet across. Another cultivar to consider, especially with a musical theme, is ‘Elvis Lives,’ although blue suede shoes in the garden are optional. “Hosta la vista, baby!”

Finally, your rhapsody in blue can be introduced to walls, fences, patios, deck railings, and gazebos with container accent pieces and vines. For example, consider the many annuals and tender perennials, from garden verbena to Verbena peruviana, and all the lobelias, petunias, and heliotropes in-between, which easily offer splendid blue and violet displays for hanging baskets and terracotta urns. For climbing plants, add some passion to your design with native maypops and blue passion flower (Passiflora spp.), the clear blue of wisteria ‘Magnifica,’ and the bountiful offerings of the genus Clematis, which provide hardy cultivars for early, mid-summer, and late blooming possibilities.

It is high time to forget about feeling blue – just let a bit of improvisation and imagination turn your garden into a rich and dazzling symphony for the senses.

Copyright 2009, Joseph M. Keyser

Don't Get Bamboozled!

A common axiom in gardening is putting the right plant in the right place. Where bamboo is concerned, most people think that the only appropriate location is somewhere on the far side of hell. Bamboo is cherished and ardently defended as a vigorous landscape screen by some, although it is usually cursed as an invasive, unstoppable menace by most others, especially irate neighbors who find spikes and spears shooting up in their lawn and garden beds.

There are more than 750 species of bamboo plants which have been introduced to North America from Asia, the Caribbean, and Latin America. Most of these woody grasses (yes, they are actually grasses!) fall within the genera Bambusa, Pseudosasa, and Phyllostachys, and are renowned for growing upwards of 16 to 40 feet, with a cane or “culm” diameter ranging from one to six inches. Many also experience a general die-back after about a dozen years, usually after flowering, which will leave a dead, yellowed bamboo jungle, until new growth repopulates the grove.

Some species are considered “clumping,” which are generally well-behaved, while the more insidious specimens are called “running bamboos,” which will swiftly produce an impenetrable and monocultural thicket as they exert their own manifest destiny. Among the most commonly sold, planted, and (ultimately) loathed of runners is Golden Bamboo (Phyllostachys aurea).

These exotic invasive bamboos have caused feuds just shy of the infamous Hatfield and McCoy dust-up. Lawsuits have been filed, bulldozers mobilized, and concrete barriers poured. And yet, for all that, people looking to screen their yards from neighbors continue to plant running bamboos, especially in narrow spaces between properties or along fence lines.

Happily, there are attractive and non-invasive alternatives to bamboo blight, but first we should address how best to control and eradicate these invaders.

To keep bamboos from running, a rhizome barrier should be used. Bamboos very seldom produce seeds, and use rhizomes, or horizontal underground roots, to spread outward. To stop this march, a barrier two-three feet deep is essential, with about two inches rising above the soil surface. Slant the barrier outward near the top to ensure that rhizomes hitting your blockade will grow upward, and not down and eventually under the barrier. Keep an eye out and cut off any roots that attempt to grow over the top. Barriers can be made from metal or concrete, although heavy 60 mil plastic is the most readily available and affordable.

Clumps of bamboo can also be dug out, as the roots are actually quite shallow. Be sure to remove any and all pieces of the rootstock, including wayward rhizomes, and keep an eye out for future incursions.

A somewhat easier approach is to cut bamboo shoots as close to the ground as possible, and thereafter snip or mow down any new shoots or pesky regrowth. Eventually, you will starve the rootstock and the plant will die, although you will need to patrol the area on a regular basis for a year or so. This technique is best used on bamboo entering your yard from a neighboring property. In fact, some homeowners simply mow down any shoots in their lawns when they cut their grass, and have seen thumb-thick shoots eventually replaced by pencil-thin sprouts, just before they disappear altogether.

For quicker, more thorough results, Jan Ferrigan, an invasive plant program manager in Virginia, recommends cutting down bamboo shoots and applying Roundup or a similar glyphosate herbicide directly inside the now-open stem, and painting the outer surface of the culm. Jan suggests carefully using the herbicide at a 25 percent concentrated solution, not the typically diluted two percent used for routine spraying. And fall is the usually recommended time for application.

Naturally, the best solution is not to plant exotic bamboos at all. And the finest alternative is, not surprisingly, a native bamboo. Generally called canebrake bamboo (Arundinaria gigantea), or southern cane, this species used to cover enormous stretches of riparian “bottom land” from the mid-Atlantic to the Midwest prairies, down through the southeast, and along the Gulf states. Amazingly, before European colonization, native Americans lived among canebrake groves several miles in width, running up to 100 miles in length. Today, there are only scattered patches of these lush thickets.

Homeowners looking for a tall, dense, yet elegant, living fence need look no further. Canebrake can reach 12 to 18 feet or more, with half- to three-quarter inch canes and medium to dark green foliage year-round. However, when shopping around, don’t confuse this species with switch cane (A. tecta), which is smaller, low growing, and more suited as a groundcover plant. And while very few garden centers and nurseries seem to carry canebrake, there are numerous sources online and through mail-order catalogs, with prices ranging from 15 to 25 dollars for one and two gallon containers.

Not interested in bamboo at all? Consider arborvitae (Thuja occidentalis) as an alternate evergreen screen. The cultivar Emerald Green is probably the most popular of standard arborvitae, growing 15-20 feet, with a spread of four-six feet. Its lustrous gem-green foliage is tolerant of cold winters and hot summers, although, as a native of the northeast, it would prefer to be watered during dry periods, and mulched three to four inches deep to retain soil moisture.

Emerald Green can be pruned if or as desired in early spring, and is often considered superior to the much overused Leyland cypress, which could also work as a screen, although it can reach 60 feet and would require substantial pruning to achieve the same effect. Other desirable cultivars include both ‘Nigra,’ which remains dark green even through the winter, featuring a pyramidal form reaching 15-25 feet and five-eight feet wide, and ‘Pyramidalis,’ with softer, bright green needles, growing to 15 feet with a four foot spread.

Another clear winner is Irish juniper (Juniperus communis ‘Hibernica’) with bluish-green foliage, and a columnar form reaching 10-12 feet. This juniper is drought tolerant, with dense upright branches. Some nurseries indicate that it can reach 15 feet with only a narrow two-four foot spread.

There are also numerous species of yews suitable for narrow space screening. All are able to handle heavy pruning and shaping, and contrast their dark green foliage with bright, fleshy red or yellowish-red berries, called arils.

Perhaps most prized of all is Irish yew (Taxus baccata ‘Fastigiata’), which is actually an English or common yew, easily growing from 15-30 feet tall, with a four-eight foot spread. [It is the most commonly grown species in Europe, and has been in use for well over 200 years.] The needles are a striking blackish-green, although other cultivars, such as ‘Fastigiata Aurea,’ while similar in form, actually feature golden foliage on its new spring growth.

Japanese Yews (Taxus cuspidata) generally tend to have a broader spread and lower growth habit, and often quite a slow growth rate. However, cross Japanese and English yews and you’ll find a hybrid (Taxus x media) showcasing some of the best assets of each parent. Many of the outstanding cultivars for living screens were developed or discovered on my native Long Island, including several by famed nurseryman Henry Hicks. The specimen bearing his name, Hicks yew (Taxus x media ‘Hicksii’), is columnar in form, 12-20 feet high, and six-ten feet across, with glossy needles, deep green on top and a pale green underneath.

Lastly, Eastern hemlock (Tsuga canadenensis) has long be valued for its light, airy needles and graceful branches, which readily accommodate heavy pruning to create a lush, dense hedge. Left on its own, however, the tree will reach 60 feet with wider spaced branches.

Copyright 2009, Joseph M. Keyser