Gardening in the Hellstrip

The hellstrip — the space between a street and a public sidewalk, also known as a tree park, boulevard, meridian, and planting strip — is getting a lot of attention these days with the publication of Evelyn Hadden’s Hellstrip Gardening by Timber Press. This comprehensive guide with gorgeous color photographs of hellstrip gardens across the country offers inspiration and visual guidance to anyone ready to tackle this final frontier.

Hellstrip gardening is nothing new to my friend Kathy, who has been adding curb appeal to her home with hellstrip plantings for 15 years. Kathy began her roadside garden when she got tired of trying to keep the lawn grass alive in the hellstrip year after year. Always keen on water conservation, Kathy wanted a low maintenance solution for this long, sunny expanse. Her large backyard garden had also become shaded over the years as the pine trees grew taller and taller, so the sunny hellstrip offered a chance to relocate her sun lovers from the backyard and to try some new plants in this totally different environment.

She began the garden by digging up a small section of sod around her mailbox, amending the soil, and planting various sedums that would be low maintenance and drought resistant. Bit by bit, the hellstrip garden grew, and then expanded to the other side of the driveway. Now it measures close to 100 feet, and boasts a wide variety of perennials. Kathy learned through trial and error which plants to grow, and which plants to avoid. Some perennials, like yarrows, were too tall and floppy. Annuals were too labor intensive, except for the portulaca that self sows and returns year after year. But there were many perennials that acclimated to this dry, sunny area with its relatively poor soil.

Mediterranean plants and herbs – many of which sport silver foliage and prefer a sunny situation with lean soil and good drainage, thrive in Kathy’s roadside garden. Sedums, Lamb’s ears, salvia, sage, alliums, fescues, rosemary, thyme, mint, sea lavender, and catmint bask in the baking hot sun. The garden delights passersby with a changing palette of blooms and foliage. In the early spring, crocus, creeping phlox and species tulips, which love the good drainage, cheer up the border with their blooms. They are followed by stately bearded irises, columbines and poppies in June, and daylilies, helianthus and coreopsis in mid summer. A prickly pear cactus at the base of the mailbox surprises visitors with its yellow flowers in July. Sedums steal the show in August. In a shadier part of the garden, hostas and heucheras provided beautiful foliage from spring to fall.

Gardening in the hellstrip has its challenges. The soil in these areas is usually cheap, compacted fill. Kathy amends it at planting time with compost, and has been top dressing with leaf mulch. Because of the distance from the house, the garden is difficult to water. Although Kathy does not irrigate regularly, newly installed plants need supplemental watering, which amounts to many trips with a watering can. Weeds easily blow into the garden and crabgrass is a particular problem. Since the hellstrip is town-owned property, large sections have been dug up utility companies several times without prior notice.

But overall, gardening in the hellstrip has been a positive experience for Kathy. Neighbors stop by to admire the garden, and Kathy receives many compliments on sprucing up the neighborhood. “The hellstrip builds community,” says Kathy. “People stop by to chat and ask about the flowers. And it gives me a chance to try plants that I couldn’t grow anywhere else in my garden.”

Invasive Vine “Swallows Up” Your Garden

I came home from a weeks vacation to find that my garden had virtually exploded while I was gone. The heavy rains of June followed by the July heat wave turned my garden into a lush jungle of towering lilies, heliopsis, and hydrangeas. The explosion of flowers was coupled with an explosion of weeds, including the invasive black swallow-wort vine that I battle every year.

Also known as Louis swallow-wort, Cynanchum nigrum is a member of the milkweed family imported to the U.S. from its native Europe as an ornamental vine. It was first noted in Ipswich, MA in 1864, escaping from the botanic garden where it is a weed and promising to become naturalized. Since then, black swallow-wort has become an invasive nuisance in the Northeast and Midwest, crowding out native plants in fields and forests. It is also a deadly host for the monarch butterfly, which lays its eggs on the vine, but its larvae do not survive feeding on this plant. Conservancy groups throughout the country are trying to educate the public about the threat of this plant to the environment.

The vines emerge in the spring, and can literally grow a foot overnight in wet weather. They quickly wind around your precious peonies, pulling the heavy blooms down to the ground, sprawl over entire shrubs, or grow right through the center of a rare epimedium that you bought from a hybridizer for a tidy sum. These vines thrive everywhere, from sun or shade, rich humus or heavy clay, alkaline or acidic soil.

Black swallow-wort sports glossy oval-shaped leaves with pointed tips, 3-4 inches long, that occur in pairs along the stem.

The small, dark purple flowers are star-shaped and borne in clusters.

The flowers are self-pollinating and quickly produce a bounty of seed pods that dangle from the stems. The seeds are equipped with their own downy parachutes that aid in wind dispersal, which begins in late July and continues through fall. The plants also spread through underground rhizomes that form large clumps.

So how do we control this thug in the garden? As with all invasive species, early detection and removal is the best approach. There are no biological controls for black swallow-wort available in the U.S. Mowing will not eradicate the plants, but will at least prevent them from forming seeds. Once seeds have formed, the plants should be carefully cut down and bagged so that the seeds dont disperse. The vines can also be dug out, but care must be taken to remove the complete root crown, which is difficult to do. Even a tiny piece of white root left behind will soon sprout into a new plant. Dug plants should be burned or bagged and disposed of in the trash.

Although I dislike using herbicides in the garden, chemical control is recommended as the most effective means for large, established infestations. Glyphosate (Roundup) is effective if sprayed on when the plants are in flower (prior to that, the plants do not have enough leaf surface area to deliver a killing dose to the roots.) If the black swallow-wort is twining around desirable plants, the glyphosate can be applied with a sponge or brush. Another alternative to spraying is to cut and dispose of the stems and apply a 100% solution of the herbicide concentrate directly to the cut stem surfaces with a small brush.

Unfortunately, once black swallow-wort appears in your garden, you will be battling it for several years. So dont wait if you see even the tiniest sprout of this tenacious vine, pull it immediately! Or you may return from vacation later this summer to find your favorite plants swallowed up by this insidious creeper!

Photos courtesy of Marie Brown

Asian Longhorned Beetle

Asian Longhorned Beetle ("ALB") is an invasive wood-boring pest that was discovered in Worcester, MA in August 2008 and in Boston in July 2010. ALB attacks maple, birch, elm, willow and other hardwoods, makingit a huge threat to the trees that grow in our parks and along every street. This pest also puts the livelihood of our state's forests as well as our nursery and maple syrup industries at risk.

ALB spreads through the transport of firewood or logs from infested areas. Once a tree is infested with ALB, there is no cure - it must be cut down.

Help protect your community from this invasive pest. Check trees for exit holes that are perfectly round and smooth, about 1⁄2 inch in diameter. In the summer, look for shiny black beetles, about 1 inch long, with bright white dots and long, banded antennae.

If you think you see ALB or ALB tree damage, report it at http://massnrc.org/pests/alb or call toll-free:1-866-702-9938

Helpful Websites:

Mass. ALB Cooperative Eradication Program: http://massnrc.org/pests/alb

ALB Media/Outreach Info: http://massnrc.org/pests/alb/albmedia.htm

USDA ALB Info: http://beetlebusters.info