Beauties and the Beasts
There is a storm brewing in the plant world and it may be coming your way. The storm is relentless… spreading wildly over the landscape. The tempest may sweep over large areas choking everything in its path but, then again, it could end up being a false alarm that need not be heeded. The storm I refer to are the vast array of plants with highly aggressive rates of growth that are commonly found in many of our landscape plantings and garden stores. These garden thugs are commonly misunderstood, often misplaced and (too commonly) maligned through no fault of their own. Their pretty faces often hide their inner desire to eat the world, one garden at a time. Realize, that in many cases, one gardener’s thug is another’s solution to a gardening dilemma. Gardeners often require the services of a garden brute when soils are hard packed, baked hot and dry, wet & soggy or choked with tree roots. Under severe garden conditions, these aggressive plants can serve a purpose, giving gardeners confidence in achieving success where other, less hardy, plants would fall victim to these harsh environments.
The challenge we face is differentiating garden thugs from true invasive plant species that can, will and do cause long term harm to our native plant environments. This definition of invasive species has spawned a civil war within the plant industry. Gardeners, environmentalists, plant producers and designers all have varied views and opinions of how best to deal with this concern. The last thing I want to do is be that guy standing atop a pile if dry tinder striking a match so let’s look at a few plants that could be considered garden thugs and discuss where they may prove effective in challenging garden areas.
Japanese Anemones, Goosenecks (Lysimachia clethroides), Christmas and Ostrich Ferns are four garden thugs that can (under certain conditions) serve gardeners very well. They all prefer slightly shaded areas and moist soil conditions. Under these ideal conditions, all are fast spreading and can choke out other neighboring plants that are not as vigorous but in large, open planting areas their fast growth is a tremendous benefit allowing fewer plants to be used in a given planting. In drier planting areas these plants will not spread as rapidly and they can be more easily maintained within their allotted space.
Groundcover plants, by definition, require a bit of thuggery to fulfill their purpose… covering the ground. The degree of vigor varies widely by plant variety so knowing which groundcover plants may be suitable for your specific needs mayl require some research. There are a few plants I would caution against. Aegopodium podagraria (bishop’s weed or gout weed), Lamiastrum galeobdolon (yellow archangel) and Houttuynia cordata (chameleon vine) are three groundcovers that exhibit extraordinary aggressiveness and should be avoided in all but the most harsh and secluded environments. Plant these with extreme care under trees with extensive roots or in planting beds surrounded by walkways, buildings or other restrictions to their spreading roots.
Vinca minor (myrtle) and English Ivy are two common groundcovers that can become very invasive and will require control efforts to maintain their behavior. Figure on annual maintenance to keep these plants under wraps. Planting these in larger areas is very popular but we need to consider what happens 10 and 20 years from now.
Ajuga and sedum are two large families of groundcover plants with some selections that are very invasive and others which are well-behaved… research the specific selections before you plant and avoid the most aggressive types in most instances. Under trees, in deep shade, in large plantings and on steep slopes the most aggressive selections may be just what is needed.
All the plants mentioned so far develop by spreading rhizomes or underground root systems. Truly invasive species may also spread by seed which is much more difficult to control. Plant like Foeniculum vulgare ‘Purpureum’ (bronze fennel), Silphum (cupflower), Grape hyacinths, Rudbeckia (Black eyed susans) and Joe Pye Weed (Eupatorium) can spread hundreds of seeds after blooming becoming a real headache if not maintained. The benefit to these plants is that control can be achieved by simply cutting off dead flowers and therefore prohibiting these seeds from spreading in your gardens.
Shrubs and trees can also be considered beastly garden thugs. Burning bush, barberry, privet, rose of sharon and bayberry are some of the shrubs that can become a problem if seeds are allowed to spread and grow. Amur and Norway maples, buckthorn and black locust are examples of trees that should not be planted in the landscape. The size and growth rate of these plants make them difficult to control besides, there are many more desirable plants to choose from.
Selecting the right plants for specific garden locations can be as difficult as it is critical so, when in doubt, consult with a qualified professional for the best results.
So whether you are evaluating plants already in your garden, looking to add more to existing plantings or starting new plantings from scratch, I hope you will be better informed of the beasts within the beauties of the plant world.
Now go outside and have fun in the dirt!