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Drought Tolerant Plants: Blue Flax

“Lewis’s prairie flax is a pretty garden ornamental suited to hot, dry sites. Each morning delicate sky blue flowers open on slender arching stems, only to fall off in the afternoon and be replaced by others the next morning. In spite of its fragile appearance, it is quite sturdy and may put out a second flush of blossoms on new growth in late summer.” — Common to the This Country: Botanical Discoveries of Lewis and Clark by Susan H. Munger

When selecting plants for a waterwise garden, it is imperative that at least a portion of the plants are easy to grow and maintain and are adapted to a wide variety of conditions. This will ensure a more successful garden, both functionally and aesthetically. Luckily, there are a number of drought-tolerant plants that pretty much anyone can grow without too much trouble. Blue flax, in my opinion, is one such plant.

You may be familiar with flax as a culinary plant, known for its edible seeds which are used to make flour (i.e. meal) and oil. Or perhaps you’ve used linseed oil, a product of flax seeds, to protect wooden, outdoor furniture or in other wood finishing projects. You may also think of linen when you think of flax; and you should, because linen is a textile made from the fibrous stems of the flax plant. All of these products generally come from a domesticated, annual flax known as Linum usitatissimum – a species that has been of benefit to humans for millenia. Various species of flax have also been planted for erosion control, fire breaks, forage for livestock, and in pollinator-friendly gardens. Flax seeds, a common ingredient in bird seed mixes, provide food for birds and other small animals. All this to say, humans and flax share a long history together, and it deserves a place in your garden.

The flax species profiled here is actually two species: Linum lewisii and Linum perenne. That’s because these two species look nearly identical and are both used as garden ornamentals and in wildflower seed mixes. They are also both known as blue flax, among myriad other common names. Due to their similiarity, L. lewisii is considered by some to be a subspecies of L. perenne.

Linum lewisii is found across western North America and received its name after being collected by a member of the Lewis and Clark Expedition. The plant collection was brought back from the expedition and determined to be new to western science. It was described and named by Frederick Pursh. Linum perenne is a European species which was introduced to North America as an ornamental and has since become widely naturalized. In 1980, a naturalized selection of L. perenne was released for use in restoration plantings under the cultivar name ‘Appar’ with the understanding that it was L. lewisii. A genetic study later revealed that the cultivar was instead L. perenne. The study also provided evidence that “North American Lewis flax and European perennial blue flax are reproductively isolated,” suggesting that they are indeed two separate species.

Despite being separate species, telling them apart can be a challenge. Blue flax plants grow from a taproot and woody base and are multistemmed, reaching two to three feet tall. The stems are thin yet stringy, wiry, and not easily torn, which helps explain why flax is such a good plant for making textiles. Short, slender leaves are alternately arranged along the length of the stems, while flower buds form at the ends of stems in loose clusters. Flowers bloom early in the day and are spent by the afternoon. They are 5-petaled, saucer-shaped, and a shade of blue – from whitish blue to deep blue – depending on the plant. Small, round, 10-chambered seed capsules form in the place of flowers, each chamber housing one or two flat, shiny, dark brown seeds. Flowers bloom daily in succession up towards the ends of stems even as the fruits of spent flowers lower on the stalk mature.

seed capsules of blue flax

A close look at their flower parts is really the only way you might be able to tell these two species apart. Blue flax flowers have five stamens topped with white anthers and five styles topped with little, yellow stigmas. The flowers of L. lewisii are homostlyous, which means their styles are all the same length and are generally taller than or about the same height as the stamens. The flowers of L. perenne are heterostylous, which means their flowers can either have styles that are much longer than their stamens or stamens that are much longer than their styles. Each plant in a population of L. perenne has either all long-styled flowers or all short-styled flowers. In a mixed population of L. perenne and L. lewisii, separating the long-styled L. perenne plants from the L. lewisii plants presents a challenge (at least for me).

long-styled blue flax flower
short-styled blue flax flower

Due to the similarity of these two species, it’s easy to see how the plants or seeds of blue flax could easily be mislabeled and sold as one species even though they are the other species. This could be a problem in a restoration planting where seed source and identity is critical, but in your garden, it’s really no big deal. Both species are great for waterwise and pollinator gardens. They are equally beautiful and easy to grow and care for. If nothing else, perhaps the challenge in identifying them will encourage you to take a closer look at your flowers and familiarize yourself with their tinier parts – an act all of us amateur botanists could stand to do more often.

The photos in this post were taken at Idaho Botanical Garden in Boise, Idaho.

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Drought Tolerant Plants: Yellowhorn

A drought tolerant garden doesn’t have to be treeless. While the pickings are slim, there is a selection of trees that, once established, are well adapted to deal with extended bouts of little to no water. One such tree is yellowhorn, a species that demands to be considered for any waterwise landscape. Yellowhorn is rare in cultivation – and also restricted in its natural distribution – but perhaps that will change as word gets around about this beautiful and resilient tree.

Xanthoceras sorbifolium is native to several provinces in northern China and has been cultivated in a number of places outside of China since at least the 1800’s. Its ethnobotanical value is well understood in China. Its leaves, flowers, and seeds are edible and medicinal, and the high oil content of its seeds make them useful for the production of biofuels. Researchers are also investigating the use of yellowhorn for ecological restoration in arid habitats where desertification is a concern.

yellowhorn in bloom

Yellowhorn is the only species in the genus Xanthoceras, but is one in a long list of trees and shrubs in the Sapindaceae family – a family that now includes maples and horse chestnuts. It is considered both a large shrub and a small, multi-stemmed tree. It reaches a maximum height of about 25 feet, but arrives there at a relatively slow pace. It tolerates a variety of soil types, but like most other drought tolerant plants, it prefers soils that don’t become waterlogged easily. Its leaves are long, glossy green, and compound, consisting of 9 – 17 leaflets. The leaves persist late into the year and turn yellow in the fall. However, late spring, when the tree is covered in flowers, is when this tree puts on its real show.

Large white flowers with yellow-green centers that turn maroon or red-orange as they age are produced on racemes at the ends of branches. Small, yellow, hornlike appendages between each of the five petals of the flowers are what gives the tree its common name. Flowering lasts for a couple weeks, after which fruits form, which are about 2.5 inches wide, tough, leathery, and somewhat pear shaped. In my experience, most of the fruits are eaten by squirrels long before they get a chance to reach maturity. The ones the squirrels don’t get will persist on the tree, harden, and eventually split open to reveal several large, dark, round seeds nestled in chambers within the fruit.

To truly appreciate this tree, it must be seen in person, especially in bloom. At that point you will demand to have one (or more) in your garden. The seeds are said to be delicious, so you should give them a try if you can beat the squirrels to them. For a more thorough overview of yellowhorn, check out this article from Temperate Climate Permaculture, and for more photos of yellowhorn in bloom, check out this post from Rotary Botanical Gardens.

Squirrel nesting in yellowhorn, getting ready to go after more fruits.

All photos in this post were taken at Idaho Botanical Garden in Boise, Idaho.

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Drought Tolerant Plants: Water Conservation Landscape at Idaho Botanical Garden

Demonstration gardens are one of the best places to learn about drought tolerant plants that are appropriate for your region. Such gardens not only help you decide which species you should plant, but also show you what the plants look like at maturity, what they are doing at any given time of year, and how to organize them (or how not to organize them, depending on the quality of the garden) in an aesthetically pleasing way. A couple of years ago, I explored the Water Efficient Garden at the Idaho State Capitol Building. This year I visited the Water Conservation Landscape at Idaho Botanical Garden in Boise, Idaho.

The Water Conservation Landscape is planted on a large L-shaped berm on the edge of Idaho Botanical Garden’s property. It is the first thing that visitors to the garden see, before they reach the parking area and the front gate. It is nearly a decade old, so the majority of the plants are well established and in their prime. Because the garden is so visible, year-round interest is important. This imperative has been achieved thanks to thoughtful plant selection and design.

This demonstration garden came about thanks to a partnership between Idaho Botanical Garden and several other organizations, including the water company, sprinkler supply companies, and a landscape designer. An interpretive sign is installed at one end of the garden describing the benefits of using regionally appropriate plants to create beautiful drought tolerant landscapes. If you ever find yourself in the Boise area, this is a garden well worth your visit. In the meantime, here are a few photos as it appeared in 2017.

February 2017

bluebeard (Caryopteris incana ‘Jason’) – February 2017

Sedum spurium ‘Dragon’s Blood – March 2017

winter heath (Erica x darleyensis ‘Kramer’s Red’) – March 2017

May 2017

avens (Geum x hybrida ‘Totally Tangerine’) – May 2017

July 2017

American cranberrybush (Viburnum opulus var. americanum ‘Wentworth’) – July 2017

Fremont’s evening primrose (Oenothera macrocarpa ssp. fremontii ‘Shimmer’) – July 2017

Fremont’s evening primrose (Oenothera macrocarpa ssp. fremontii ‘Shimmer’) – July 2017

August 2017

cheddar pink (Dianthus gratianopolitanus ‘Firewitch’) – August 2017

smoketree (Cotinus coggyria ‘Royal Purple’) – August 2017

gray lavender cotton (Santolina chamaecyparissus) – September 2017

showy stonecrop (Hylotelephium telephium ‘Matrona’) – September 2017

showy stonecrop (Hylotelephium telephium ‘Matrona’) – September 2017

Adam’s needle (Yucca filamentosa ‘Color Guard’) – October 2017

fragrant sumac (Rhus aromatica ‘Gro-Low’) – October 2017

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Drought Tolerant Plants: Pearly Everlasting

Despite being such a widely distributed and commonly occurring plant, Anaphalis margaritacea is, in many other ways, an uncommon species. Its native range spans North America from coast to coast, reaching up into Canada and down into parts of Mexico. It is found in nearly every state in the United States, and it even occurs throughout northeast Asia. Apart from that, it is cultivated in many other parts of the world and is “weedy” in Europe. Its cosmopolitan nature is due in part to its preference for sunny, dry, well-drained sites, making it a common inhabitant of open fields, roadsides, sandy dunes, rocky slopes, disturbed sites, and waste places.

Its common name, pearly everlasting, refers to its unique inflorescence. Clusters of small, rounded flower heads occur in a corymb. “Pearly” refers to the collection of white bracts, or involucre, that surround each flower head. Inside the bracts are groupings of yellow to brown disc florets. The florets are unisexual, which is unusual for plants in the aster family. Plants either produce all male flowers or all female flowers (although some female plants occasionally produce florets with male parts). Due to the persistent bracts, the inflorescences remain intact even after the plant has produced seed. This quality has made them a popular feature in floral arrangements and explains the other half of the common name, “everlasting.” In fact, even in full bloom, the inflorescences can have a dried look to them.

pearly-everlasting-6

Pearly everlasting grows from 1 to 3 feet tall. Flowers are borne on top of straight stems that are adorned with narrow, alternately arranged, lance-shaped leaves. Stems and leaves are gray-green to white. Stems and undersides of leaves are thickly covered in very small hairs. Apart from contributing to its drought tolerance, this woolly covering deters insects and other animals from consuming its foliage. In The Book of Field and Roadside, John Eastman writes, “Insect foliage feeders are not numerous on this plant, owing to its protective downy ‘gloss.’ … The plant’s defensive coat seems to prevent spittlebug feeding on stem and underleaves. The tomentum also discourages ant climbers and nectar robbers.”

pearly-everlasting-5

Not all insects are thwarted however, as Anaphalis is a host to the caterpillars of at least two species of painted lady butterflies (Vanessa virginiensis and V. cardui). Its flowers, which occur throughout the summer and into the fall. are visited by a spectrum of butterflies, moths, bees, and flies.

Because the plants produce either male or female flowers, cross-pollination between plants is necessary for seed development. However, plants also reproduce asexually via rhizomes. Extensive patches of pearly everlasting can be formed this way. Over time, sections of the clonal patch can become isolated from the mother plant, allowing the plant to expand its range even in times when pollinators are lacking.

The attractive foliage and unique flowers are reason enough to include this plant in your dry garden. The flowers have been said to look like eye balls, fried eggs, or even, as Eastman writes, “white nests with a central yellow clutch of eggs spilling out.” However you decide to describe it, this is a tough and beautiful plant deserving of a place in the landscape.

pearly-everlasting-4

Read more:

Photos in this post are of Anaphalis margaritacea ‘Neuschnee’ and were taken at Idaho Botanical Garden in Boise, Idaho.

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Drought Tolerant Plants: The Yarrows

Few plants are as ubiquitous and widespread as the common yarrow, Achillea millefolium. A suite of strategies have made this plant highly successful in a wide variety of habitats, and it is a paragon in terms of reproduction. Its unique look, simple beauty, and tolerance of tough spots have made it a staple in many gardens; however, its hardiness, profuseness, and bullish behavior have also earned it the title, “weed.” Excess water encourages this plant to spread, but in a dry garden it tends to stay put (or at least remain manageable), which is why it and several of its cousins are often included in or recommended for water efficient landscapes.

Achillea millefolium - common yarrow

Achillea millefolium – common yarrow

Common yarrow is in the aster family (Asteraceae) and is one of around 85 species in the genus Achillea. It is distributed throughout North America, Europe, and Asia. European plants have long been introduced to North America, and hybridization has occurred many times among the two genotypes.

Yarrow begins as a small rosette of very finely dissected leaves that are feathery or fern-like in appearance. These characteristic leaves explain its specific epithet, millefolium, and common names like thousand-leaf. Slightly hairy stems with alternately arranged leaves arise from the rosettes and are capped with a wide, flat-topped cluster of tightly-packed flowers. The flower stalks can be less than one foot to more than three feet tall. The flowers are tiny, numerous, and consist of both ray and disc florets. Flowers are usually white but sometimes pink.

The plants produce several hundred to several thousand seeds each. The seeds are enclosed in tiny achene-like fruits which are spread by wind and gravity. Yarrow also spreads and reproduces rhizomatously. Its roots are shallow but fibrous and abundant, and they easily spread horizontally through the soil. If moisture, sun, and space are available, yarrow will quickly expand its territory. Its extensive root system and highly divided leaves, which help reduce transpiration rates, are partly what gives yarrow the ability to tolerate dry conditions.

john eastman

Illustration of Achillea millifolium by Amelia Hansen from The Book of Field and Roadside by John Eastman, which has an excellent entry about yarrow.

Common yarrow has significant wildlife value. While its pungent leaves are generally avoided by most herbivorous insects, its flowers are rich in nectar and attract bees, butterflies, beetles, flies, and even mosquitoes. Various insects feed on the flowers, and other insects visit yarrow to feed on the insects that are feeding on the plant. Despite its bitterness, the foliage is browsed by a variety of birds, small mammals, and deer. Some birds use the foliage in constructing their nests. Humans have also used yarrow as a medicinal herb for thousands of years to treat a seemingly endless list of ailments.

Yarrow’s popularity as an ornamental plant has resulted in the development of numerous cultivars that have a variety of flower colors including shades of pink, red, purple, yellow, and gold. While Achillea millefolium may be the most widely available species in its genus, there are several other drought-tolerant yarrows that are also commercially available and worth considering for a dry garden.

Achillea filipendulina, fern-leaf yarrow, is native to central and southwest Asia. It forms large, dense clusters of yellow-gold flowers on stalks that reach four feet high. Its leaves are similar in appearance to A. millefolium. Various cultivars are available, most of which have flowers that are varying shades of yellow or gold.

Achillea alpina, Siberian yarrow, only gets about half as tall as A. filipendulina. It occurs in Siberia, parts of Russia, China, Japan, and several other Asian countries. It also occurs in Canada. Unlike most other species in the genus, its leaves have a glossy appearance and are thick and somewhat leathery. Its flowers are white to pale violet. A. alpina is synonymous with A. sibirica, and ‘Love Parade’ is a popular cultivar derived from the subspecies camschatica.

Achillea x lewisii ‘King Edward,’ a hybrid between A. tomentosa (woolly yarrow) and A. clavennae (silvery yarrow), stays below six inches tall and forms a dense mat of soft leaves that have a dull silver-gray-green appearance. Its compact clusters of flowers are pale yellow to cream colored. Cultivars of A. tomentosa are also available.

Achillea ptarmica, a European native with bright white flowers, and A. ageritafolia, a native of Greece and Bulgaria that is low growing with silvery foliage and abundant white flowers can also be found in the horticulture trade along with a handful of others. Whatever your preferences are, there is a yarrow out there for you. Invasiveness and potential for escape into natural areas should always be a concern when selecting plants for your garden, especially when considering a plant as robust and successful as yarrow. That in mind, yarrow should make a great addition to nearly any drought-tolerant, wildlife friendly garden.

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Drought Tolerant Plants: The Junipers

When I first developed a real interest in plants, I was in the heyday of my zine writing career. As my interest in gardening grew, writing a zine about it became inevitable. Initially I envisioned the zine as a journal of sorts – the journal of a budding horticulturist (pun intentional). Since I was new to gardening – and plants in general – the zine was meant to follow my journey as I explored this new world.

A zine needs a name though, so what would I call it? It didn’t take long for me to land on, The Juniper. I was familiar with a common disdain for the unsightly, overgrown, neglected, evergreen shrub full of spiders and cobwebs that for whatever reason was at one point planted right outside just about every house in America (a fire hazard, by the way). I was aware that many people were resorting to tearing them out, cursing as they battled the pokey, dirty, half dead things.

That was basically all I knew about junipers – they were common landscape plants that were just as commonly despised. My affection for freaks, geeks, outsiders, and rejects led me to name my zine after a shrub that everyone hated. I guess I just felt like we had something in common, and that despite being the bane of people’s existence, it deserved some recognition.

the juniper zine

And it does. Junipers are an important species in their natural habitats. In some areas they are dominant features to the point where entire plant communities are named after them. Consider the piñon-juniper woodlands of western North America – prominent steppe habitats that occur throughout high desert regions and support diverse forms of wildlife unique to this part of the world. Dan Johnson writes in the book, Steppes, “the piñon-juniper zone dominates huge expanses of the West in varying stages of  health, providing a wealth of habitats and resources to the wildlife and the people who call it home.”

Johnson goes on to describe some of these habitats:

In the Colorado Plateau this zone is dominated by Pinus edulis and Juniperus osteosperma, with J. scopulorum occupying drainages with more moisture. In the Great Basin, P. edulis is replaced by P. monophylla as the dominant piñon pine, still mixing with J. osteosperma, yet as one moves west, this juniper is increasingly replaced by J. occidentalis. Move farther north, and J. occidentalis dominates completely, with neither piñon pine making an appearance.

The genus Juniperus is in the cypress family (Cupressaceae) and includes up to 67 species, at least 13 of which are native to North America. They are long-lived plants that range from prostrate, sprawling groundcovers to expansive, bushy shrubs to tall, narrow trees. Their foliage is evergreen and can be either needle-like or scale-like. Most juniper species have needle-like foliage in their seedling and juvenile stages and then scale-like foliage at maturity. Some species, like J. communis, never develop scale-like foliage. Junipers are gymnosperms, so their reproductive structures are housed in cones. However, their cones are fleshy and so are commonly (and mistakenly) referred to as berries or fruits. Juniper cones are most often blue or gray-blue, but in some species they have a red, brown, or orange hue.

In general, junipers are quite drought tolerant, particularly those species that are adapted to hot, dry climates. Again referring to piñon-juniper steppes, Johnson writes, “in prolonged periods of drought, the piñon pines seem to suffer long before the junipers; whole hillsides of pine may go brown, leaving islands of olive-green juniper relatively unscathed.” In the book, Shrubs of the Great Basin, Hugh Mozingo attributes this drought toughness to the scale-like leaves: “Because they are smaller and so closely appressed to the twigs, these scale-like leaves are a superior adaptation to the frequently very dry conditions in piñon-juniper communities.” This herculean ability to survive on little water makes them a great addition to a dry garden.

But we may first have to get over our disdain for them. As this post on Chicago Botanic Garden’s website puts it: “Junipers have suffered from overuse and underimagination.” (This article also examines our hatred of juniper bushes). Probably a bigger problem is that, like so many other plants used in a landscape, mature height and width often isn’t taken into consideration, and rather than removing a plant when it gets too big for the site, sheers or a hedge trimmer are regularly deployed. I’m not a huge fan of the sheered look. I much prefer a more natural form to the boxes and globes that are so common in commercial and residential plantings. I’m even less of a fan of the misguided inclination to force a plant to fit in a space that it isn’t meant to be (unless you’re a bonsai artist, I guess). This treatment is what leads to exposing the ugly, brown insides of a juniper shrub – an unsightly look that only makes people hate them more.

Brown insides of juniper shrub exposed after years of forcing the plant to fit in a site that is too small for its britches.

Brown insides of juniper shrub exposed after years of forcing the plant to fit in an improper site.

There are numerous commercially available cultivars of juniper species, offering a plethora of sizes, shapes, and forms as well as various colors of foliage. For small or narrow areas, select dwarf varieties or columnar forms that won’t need to be kept in check, and in all cases let the plant express its authentic self, controlling the urge to sheer and shape it against its will.

As if their natural beauty and low water requirement wasn’t enough, junipers are also great for supporting wildlife. Birds and other animals use them for cover and for nesting sites. The fleshy cones are edible, the shredding bark is used for nesting material, and the evergreen foliage provides much needed protection during winter months. Oh and, among many other benefits that junipers offer humans, their aromatic, fleshy cones have culinary value and are used to flavor gin.

I don’t want to leave the impression that I am opposed to pruning and shaping shrubs. For aesthetic reasons, I think it should be done. However, my opinion is that unnatural shapes should be avoided. Sure, boxed hedge rows have their place in certain types of gardens, but my preference is towards more natural shapes. The following video by University of Illinois Extension provides a brief tutorial on how to achieve that.   

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Book Review: Hellstrip Gardening, part three

The second section of Evelyn J. Hadden’s book, Hellstrip Gardening, is all about the unique challenges and obstacles one faces when gardening in that stretch of land between the sidewalk and the road. I highlighted some of those challenges last week. This week we are into the third section of Hadden’s book, the part that is all about designing, building, and managing a curbside garden. As I have read through this book, I have begun to look at hellstrips in a much different light. They are no longer boring sections of yard with little potential, but instead are full of possibility and have unique characteristics involving publicity and functionality that are absent from most of the rest of the urban landscape. Now that we are in the creation phase of the book, this fact becomes abundantly clear.

Choosing a Style

When deciding how to design and plant your curbside bed, it is important to consider – along with aesthetics – the functions you wish to achieve (storm water runoff collection, food production, wildlife habitat, etc.) as well as how you are going to maintain it. You may decide to embrace minimal maintenance with a mass planting of a single species or mass plantings of a handful of species in sections called drifts. This can be very attractively done, but it also has the risk of a disease or pest wiping out a section of plants. A mass planting of ground covers acts as a living mulch and will eliminate the need to replenish non-living mulch. Hadden provides descriptions of a few styles of garden design, such as formal, naturalistic, cottage garden, and stroll garden, each with their virtues and limitations. Growing food is also an option in a hellstrip. If this is the option you choose, keep the bed looking full by intermixing flowers and crop plants, growing perennial crops, and staggering planting times. Ultimately the style of the garden is the preference of the gardener; however, the environmental conditions of the hellstrip must also be a consideration.

Choosing Plants

Because hellstrips are by nature public gardens, they are the ideal place for plants that appeal to the human senses – plants that invite interaction. Hadden calls these plants “friendly plants.” They are plants that are aromatic, have interesting textures and bold colors, “feel great underfoot,” have “aesthetically pleasing symmetry,” and have unusual flowers or unique foliage. Hadden asserts that, “plants that invite touching engender good will,” so consider the ways that your hellstrip might make you a better neighbor.

Their public nature also means that hellstrip gardens are not the place for rare and valuable plants, and instead are ideal for easily replaceable and self-repairing plants. This includes perennials that are easily divided, shrubs that reproduce by layering, creeping plants that send out runners, and plants with seeds that are easily collected and can be sown in bare spots. One option is to plant only annuals. This eliminates the loss of plants during the winter when snow, sand, and/or salt are deposited in the beds by road clearing equipment. Just be sure to protect the soil with mulch or a cover crop during the cold months of the year.

A hellstrip is also an ideal location for an alternative lawn. Traditional lawns require loads of water and fertilizer and regular mowing in order to stay looking good. There are lots of other grasses and ground covers available now that are drought tolerant, require little or no fertilizer, don’t need to be mowed often or at all, and are still very attractive. Hadden has a website all about lawn alternatives called Less Lawn.

The seed heads of blue grama (Bouteloua gracilis), one of many attractive alternatives to traditional turfgrass. (photo credit: www.eol.org)

The seed heads of blue grama grass (Bouteloua gracilis), one of many attractive alternatives to traditional turfgrass. (photo credit: www.eol.org)

When selecting plants for your hellstrip garden, consider the conditions it will have to endure. Unless you want to make serious amendments in order to accommodate certain plants, it is probably best to choose plants that are already adapted to your site. One way to determine this is to observe sites similar to yours and see what is thriving there; particularly make note of plants that look like they have been there for a while. Also, feel free to ask local experts at garden centers and public gardens what they might recommend for your site.

Earthshaping

“Diverse topography makes a more visually interesting garden, and it adds microclimates, letting you grow more diverse plants.” Shaping a curbside bed can also serve other functions such as softening traffic noise, defining pathways, collecting runoff, and providing wildlife habitat. When building a large berm, first create a rocky base and then fill in the spaces between the rocks with sand and small gravel. After that, add topsoil and firmly pack it down with machinery or a rolling drum. Small berms can be formed by simply piling up excess soil or turning over sections of sod and piling them up. Maintain good plant coverage on berms in order to reduce erosion, and consider planting shrubs with extensive root systems like sumac (Rhus sp.) and snowberry (Symphoricarpos sp.).

Hellstrips are ideal locations for rain gardens and bioswales since they are typically surrounded by impervious surfaces. Storm water can be directed from these surfaces into your rain garden, thereby reducing the amount of storm water runoff that must be handled elsewhere. Hadden provides a brief overview on how to construct a rain garden; the process is too detailed to go into here. If you are serious about building one, it is important to do your research beforehand to be sure that it is built properly. There are several great resources available; one that I would recommend is Washington State University Extension.

Partnering with Nature

Time spent managing and maintaining your hellstrip garden can be greatly reduced when it is well planned out, contains plants that are suited to the site, and has good soil health. Helping you achieve these things is essentially what Hadden’s book is all about. Watering properly and wisely is key to the success of your hellstrip garden. Hadden suggests organizing plants into “irrigation zones,” separating those that need little or no water from those that need frequent or regular watering. When you do water, water “thoroughly and infrequently to maximize deep root growth and drought resistance.” Consider installing a drip irrigation system, particularly one that will direct the water to the roots of the plants and deliver it slowly. Avoid watering areas where there are no plants, as this encourages weed growth.

Mostly likely you will be doing some amount of trimming and pruning in your hellstrip. Consider how you will handle this plant material. You may choose to cut it up into fine pieces and leave it as mulch; or maybe you have a compost pile to add to. Large woody materials can be placed in a section of your property set aside for wildlife habitat. Choosing plants that will not outgrow the space will reduce the amount of pruning you will need to do.

As much as Hadden is an advocate for alternatives to conventional lawns, she is also an advocate for reducing the use of gas-powered leaf blowers. Nobody enjoys hearing the clamor of a smelly, polluting leaf blower echoing through the neighborhood, so be a good neighbor and use a broom or rake instead. You will probably enjoy the task more as you listen to nature, get some exercise, and revel in your garden.

Continued focus on building healthy soil is paramount to the ongoing success of your curbside garden. Continue to add organic matter by letting some of the plant litter lie and decompose. Plant nitrogen fixing species like lupines (Lupinus sp.) and false indigos (Baptisia sp.). As much as possible avoid compacting the soil, especially when it is wet, and keep tilling and digging to a minimum once the garden is planted.

Partidge pea (Chamaecrista fasciculate), an annual plant in the pea family (Fabaceae). One of many nitrogen fixing plants that can help improve soil health. (photo credit: www.eol.org)

Partridge pea (Chamaecrista fasciculata), an annual plant in the pea family (Fabaceae). One of many nitrogen fixing plants that can help improve soil fertility. (photo credit: www.eol.org)

Again, this is only a fraction of what Hadden discusses in this section of her book. Consult the book for more of her wisdom. The final section of Hellstrip Gardening is a long list of plants that are “curbside-worthy” complete with photos and descriptions. Next week’s post will be all about a particular type of hellstrip garden that employs a subsection of those plants.