Invasive Plants vs. Aggressive Growers
Not every overly enthusiastic plant is invasive and plants can be invasive in one area and not another. Get to know which plants are aggressive in your area and especially your growing conditions, which greatly affect how well a plant grows. If you have full sun and sandy soil, you are not going to have a problem with Petasites, which spreads with abandon in boggy areas. There are two basic ways plants spread out and take over your garden.
Profuse Self-seeding Plants
Aggressive self-sowers tend to be more of a problem in warm climates, where they are not kept in check by long, frozen winters. However, there are several that will spread even in colder zones, like maiden grass( Miscanthus) and butterfly weed.
Plants that Spread by Runners
It’s the aggressive plants that spread by rhizomatous rhizomes that present the biggest problem. A good tip-off that a plant is a potential aggressor is when it’s described as vigorous. Ask anyone who has ever planted running bamboo or ribbon grass. Some folks love these plants to still want these aggressive spreaders in their gardens. If you decide to give them a try, controlling them can be an ongoing chore. The following techniques will help control them, but they won’t contain them entirely. The list of aggressive plants is long and varies from area to area. It includes trees, shrubs, ornamental plants, and edibles. There isn’t room here to list them all, but here are 10 common garden plants that you might not have suspected. Still, it’s a very attractive plant, with flowers in pinks, reds, purples, and near white. Butterflies love them, but many varieties are prone to powdery mildew, so give them plenty of room for airflow. Bee balm plants tend to look a bit ragged, after blooming. Don’t be afraid to cut them back, almost to the ground. They will regrow and probably bloom again. USDA Hardiness Zones 4-9. Gooseneck Loosestrife can look like a gaggle of geese when it’s in bloom. The flowers curve down, then up, like beaks. It usually takes a few years before it starts sending out its rhizomes in earnest, but don’t become complacent, it will happen eventually. Purple Leaved Loosestrife is perhaps the worst offender, of the two. It looks very pretty when the purple leaves first come out in the spring. The yellow flowers aren’t much to speak of and the purple-colored leaves quickly fade to green. And it spreads. And spreads. And spreads. USDA Hardiness Zones Gooseneck Loosestrife 3-8/Purple Leaved Loosestrife 3-9. If you’re mostly interested in the leaves and don’t care much about the flowers, you should try ‘Helen Von Stein.’ This variety is sterile, so there will be no self-sowing. It doesn’t produce that many flowers to begin with, but the leaves are larger than other types and they stay attractive longer. USDA Hardiness Zones 4-10.
Ground covers you can walk on
Wormwood is happiest, and most vigorous, in full sun and well-drained, moderately rich soil. It’s easy to start from seed or root cuttings. If you really want more plants, simply lift the suckers and transplant elsewhere. USDA Hardiness Zones: Zones 3-9. On the plus side, wormwood is a medicinal herb with many uses, including as a de-wormer. It supposedly repels other insects, including slugs and moths.
