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Published July 06, 2015, 07:28 AM

Growing Together: 'Not in my backyard' plants should carry warning labels

Sometimes I feel sorry for plants because of our expectations. We want them to grow rapidly because we can't wait forever for plants to spread and "fill in." But then we wish they had the good sense to stop precisely at our desired boundary. Vigorous plants are great or terrible, depending on your current viewpoint.

By: Don Kinzler, Forum News Service

Sometimes I feel sorry for plants because of our expectations. We want them to grow rapidly because we can't wait forever for plants to spread and "fill in." But then we wish they had the good sense to stop precisely at our desired boundary.

Vigorous plants are great or terrible, depending on your current viewpoint. When families brought dandelions over on the Mayflower, they considered them a wonderful salad crop for the New World. Dandelions were nonexistent in North America previously, and now look at them.

Such plants belong in a special category. They have a very definite time and place. Plants that spread vigorously are valuable in the proper location, if we are aware of their capabilities and keep a watchful eye.

Just because these plants can escape their bounds doesn't mean they shouldn't be planted. So, when you're shopping at the local garden center and encounter the plants we're about to discuss, I'm hoping you won't say "Some guy named Kinzler said those should never, ever be planted."

Following is a list of plants that might contain warning labels. As one of my horticulture professors, Neal Holland, used to say "forewarned is forearmed."

Vines

-- Virginia Creeper (Parthenocissus quinquifolia). Beautiful on wire fences. Needs support where desired, but can easily crawl onto surrounding shrubs and flowers. Trim as needed.

-- Engelmann Ivy (Parthenocissus engelmannii). Similar to Virginia creeper, but its suction cups allow it to cling to masonry or solid wood surfaces. Same cautions.

-- Sweet Autumn Clematis (Clematis paniculata). Fluffy white seed clusters allow it to self-sow into surrounding landscapes. Pretty, but invasive.

Shrubs

-- Sumac (Rhus species). Creates mass plantings for roadside landscapes and naturalized settings, where it provides brilliant scarlet autumn color. It suckers in the home landscape, so is best suited for hard-to-fill corners and spaces.

-- Ural False Spirea (Sorbaria sorbifolia). Fern-like foliage becomes coppery orange in fall. White flower panicles are attractive in mid-summer. Spreads slowly outward.

-- Redtwig Dogwood (Cornus sericea). The common dogwood so useful and vigorous in shade spreads outward by stems that root along the ground. They also produce berries whose seed is dropped by birds causing seedlings in unwanted spots.

Trees

-- Russian Olive (Eleagnus angustifolia). Rapid grower with attractive silver foliage and interesting, natural growth forms. Seeds are carried by birds that spread new trees to fence lines and other spots where birds sit.

-- Almost all seed-bearing trees. Luckily most tree varieties (other than fruits) developed over the past 20 years have been selected for seedless traits. Older parts of our cities battle vigorous little seedlings of elm, ash, maple and box elder that pop up in flower beds, landscapes and gardens.

Low-growing perennials and groundcovers

-- Lily of the Valley (Convallaria majalis). Deep green foliage 6 inches tall with fragrant bell-shaped flowers provides solid cover in shaded corners.

-- Bishop's Weed, also called goutweed and snow-on-the-mountain (Aegopodium podograria). Variegated white/green/cream foliage 8 inches high prefers shade or part shade. Heat and too much sun causes crisp, brown leaf margins. Vigorous spreader.

-- Sedum (low-growing, spreading types). Perfect for hot, sunny locations where a groundcover is needed.

-- Variegated Archangel Deadnettle, also called Lamium. (Lamiastrum galeobdolon). Silver and green leaf patterns on vigorous groundcovers perform well in shade. Varieties of the species maculatum with pink or white flowers are less invasive.

-- Mints. Although they're flavor is great, many mint species can easily spread beyond their intended boundary.

-- Lamb's Ears (Stachys byzantina). The name aptly describes the wooly white pointed leaves on this low-growing spreader. Purple-pink flower stalks rise 15 inches above foliage.

-- Carpetbugle (Ajuga). Low-growing groundcover has blue-purple blossoms on green, burgundy or variegated foliage.

-- Birdsfoot Trefoil (Lotus corniculatus). Sometimes included in wildflower mixtures, the yellow-flowered groundcover often spreads along roadsides.

Perennial flowers

-- Yarrow (Achillea). Pastel flat-topped flower clusters with ferny foliage are attractive, but they scatter seed profusely.

-- Bellflower (Campanula). A large family of blue or white colored flowers. Newer varieties of clustered bellflower (C. glomerata) are much less rampant than the old-fashioned weedy creeping bellflower.

-- Ribbon Grass (Phalaris arundinacea). Variegated white and green striped grass growing to 30 inches invades surrounding landscape unless contained.

-- Hardy Ferns. Perfect in shady, moist spots, but spreads vigorously.

-- Chinese Lantern (Physalis). Grown for its papery lantern-shaped pods, it becomes weed-like.

-- Goldenrod (Solidago). Often included in wildflower mixtures, it easily encroaches on its surroundings.

Although I tease about "not in my backyard," we've enjoyed most of these in our landscape. In the proper locations, these plants are all beautiful. But if purchased unaware and planted in the wrong spot, you might eventually find a machete useful.

Don Kinzler, a lifelong gardener, worked as an NDSU Extension horticulturist and owned Kinzler's Greenhouse in Fargo. Tune in to his weekly radio segment from 11 to 11:30 a.m. Fridays on WDAY Radio 970. Readers can reach him at forumgrowingtogether@hotmail.com.

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