The Designing Gardener owes all gardeners an apology. The Designing Gardener promises “Solutions for Frustrated Gardeners”, but an earlier blog post, Nasty Plants, merely listed some of the worst invasive plants and offered no solutions. Time to fix that. But in spite of their bad rap, many evil plants have positive qualities such as brilliant fall color (Burning Bush), screening potential (Golden Bamboo) or filling in bare spots (Creeping Jenny), qualities that sustain their demand in spite of their thuggish behavior. So every attempt was made to select non-invasive substitutes that had similar qualities, and although many choices, but not all, are natives or even a different species of the invasive plant, they are all well-behaved.
Taking a closer look at the first of the Nasty Plants, Euonymous alatus, this shrub has the power to seduce an unwitting gardener with its dazzling fall foliage and plentiful berries. Do not succumb. Resist the temptation to plant Burning Bush, since there is no known biological control and every one of those berries consumed by a passing bird contains the seed to start a new colony of burning bushes, hell bent on choking out all neighboring plants. A Better Choice is Highbush Blueberry, Vaccinium corymbosum, a native plant that has been around for thousands of years according to archeological records and boasts fall color that rivals Burning Bush. Plant Highbush Blueberries in full sun, acidic, evenly moist soil in USDA Zones 5-8. Since they do not self-pollinate select varieties that bloom at the same time to ensure a bumper crop, and unlike the toxic berries of the Burning Bush, these are berries to relish.
Another Nasty shrub often grown for its winter display of berries, Berberis thunbergii, has run rampant through New England, the Mid-Atlantic region, the Southeast and as far west as Wisconsin. With no known predators – not even the deer will touch it – or biological control, the only way to eliminate the plant is to zap it with a dose of RoundUp or a similar herbicide containing glyphosate. However, glyphosate is a reputed carcinogen, and a jury in California recently awarded $289 million dollars to a cancer victim who alleged that long-term use of RoundUp caused his illness. Skip the RoundUp. A Better Choice is to plant an Ilex verticillata. This Eastern United States native hardy in USDA Zones 3-9 blooms in June and July and produces sprays crowded with red berries through the entire winter. Site your Winterberry in full sun and moist acidic soil, and to help Mother Nature along plant one male Winterberry in the midst of six females and watch what happens.
The next thug in the list of Nasty Plants, Golden Bamboo deserves the top award for aggressive behavior; it is known to send rhizomes as far as 30 feet away from the mother plant. A variety of running bamboo, Phyllostachys aurea was introduced in Alabama in 1822 as a screening plant and now has invaded USDA Zones 6 through 10. A Better Choice for a screen is Fargesia nitida, a clumping bamboo that grows anywhere in the country except where the summers are hot and humid. Preferring partial shade and rich soil, this native of Szechuan province was first discovered by a French missionary, Paul Farges, whose passion was collecting plants when not proselytizing. Two fine cultivars of this 10-12 foot clumping bamboo are F. nitida ‘Blue Fountain’ and F. nitida ‘Jiuzhaigou’ an outstanding variety with red canes.
The Nasty Plants category is not limited to shrubs but includes flowering perennials as well, and leading the Most Unwanted List is the villainous Purple Loosestrife responsible for choking out native wetland plants and destroying animal habitats all across the country. Although a natural predator, the black margin loosestrife beetle, can decimate wide swaths of Lithrum salicaria, the beetles must munch around the clock since a single plant produces more than 2.5 million seeds a year. A Better Choice is Liatris spicata a loosestrife look-alike without the obnoxious behavior. Give your Blazing Star full sun and medium water and you will be rewarded a profusion of pale purple bottlebrush flowers in July and August attracting a variety of butterflies, bees and birds.
Over 40 countries have branded Leucanthemum vulgare a noxious weed invading fields, roadsides, and pastures depriving beef and dairy cattle of valuable grazing land. In this country every state including Alaska and Hawaii has reported an invasion of this Nasty Plant, the Ox-Eye Daisy. A Better Choice, Leucanthemum x superbum is a dead ringer for its noxious cousin, but with better manners. Hardy in USDA Zones 5-9 the Shasta Daisy will bloom from summer well into fall if given full sun, average water and rich soil. This daisy, named for the snow-covered Mt. Shasta in California, was developed by Luther Burbank and honored as Perennial Plant of the Year in 2003.
The groundcovers too have their share of Nasty Plants, and Lysimachia nummularia and Vinca minor vie for the distinction as the worst of the bad boys. Taking a closer look at Creeping Jenny, Lysimachia nummularia, creeps by rhizomes and thrives in full sun to part shade and medium to wet soils; in short, it’s not fussy about where it puts down roots. Named for a Macedonian King of Thrace, Lysimachius would be horrified to know he leant his name to such a noxious weed. A much Better Choice is Russian Stonecrop, Sedum kamtschaticum, and the cultivar ‘Golden Carpet’ produces yellow star flowers in early summer similar to those of a Creeping Jenny. Give this fast growing groundcover a hot, dry sunny site with poor soil, and watch it flourish. As an added bonus, propagation of this Sedum is a simple task; just break off a stem in early summer and stick it in the soil.
One of the most widely planted groundcovers, Vinca minor, or Creeping Myrtle is popular with home gardeners for its waxy evergreen leaves, rapid growth, resistance to pests and diseases, and those delicate pale blue flowers. Curb your enthusiasm for this Nasty Plant; once it gets settled in nothing, except the notorious glyphosate, can stop its rampage. A Better Choice is the North American native groundcover Chrysogonum virginianum, also known as Goldenstar. It too has all the desirable qualities of myrtle but is much better behaved. Preferring part shade to full shade and moist soil in USDA Zones 5-9, this woodland beauty produces a profusion of yellow flowers in May that last well into the fall.
Remember kudzu, “The Vine That Ate the South”? Well, Amur Honeysuckle soon may be known as “The Vine That Ate the Woodlands” and indeed, many states have banned the sale or propagation of this Nasty Plant. Introduced in this country from Japan as an ornamental vine in 1855, Lonicera maackii quickly escaped from home gardens and laid siege to the nation’s woodlands. A Better Choice to drape over an arbor or fence is the South Eastern native Trumpet Honeysuckle, Lonicera sempervirens, same family, different species. This vine, which grows happily in USDA Zones 4-9 in full sun with average water and soil, produces a flush of scarlet flowers in May and June attracting hummingbirds, butterflies and bees.
For those gardeners who prefer the subtle yellow blossoms of L. maackii, chose the L. sempervirens cultivar ‘Sulphurea’.
The last in the Nasty Plant series, English Ivy or Hedera helix is a rampant clinging vine that scales tree trunks, cliffs, walls – in short, anything vertical – and latches on to its host with remarkable tenacity. Invading all but the Plains States and Alaska, this marauder is not fussy about growing conditions, but why consider planting English Ivy when Asian Star Jasmine is a Better Choice? This evergreen climber sports glossy green leaves that are dotted with dainty fragrant white flowers in summer and all that is required to keep your Trachelospermum asiaticum happy in USDA Zones 7-11 is full to part sun and regular water. Even the Royal Horticultural Society acknowledged the virtues of the Asian Star Jasmine with its prestigious Award of Garden Merit.
So do not be seduced by a Nasty Plant because it spreads rapidly, climbs vigorously or screens effectively, but instead select a Better Choice, and your garden will need no draconian restraints to control bad plant behavior.