Perennials that spread can be a great thing, or a disastrous mistake depending on where they have been planted. The plant might be a native species or a special cultivar. Often plants become a nuisance spreading plant when they are brought in from other areas either deliberately or by chance, and often it is native plants that take advantage of the superior conditions of a cultivated garden.
Vigorous is one thing, invasive is quite another. If used in the perennial border you really need to keep on top of them regularly and weed out any extra plants that are outgrowing their boundaries, preferably while the plants are still very small. Some invasive plants can be planted into containers which are then sunk into the ground to prevent roots from escaping into the neighboring soil. Better yet, the best placement for spreading plants is to give them their own area to fill in. Here they can naturalize in a meadow, or become a great ground cover for a difficult area. The bottom line for plants that spread really is, right plant in the right place.
Listed below are few of the more common invasive plants that gardeners often find out about after the fact. If you are thinking of planting any of these plants, be sure you are putting them in an area where they will not cause you grief.
Invasive Plant List
Goutweed (bishop’s weed) (Aegopodium podagraria), is a beautiful variegated foliage plant. Lovely spikes of white flowers that look like Queen Anne’s Lace add to the charm. In the right conditions this plant can go for miles so beware. Use it only in far out areas as a ground cover.
Chinese Lantern (Physalis alkekengi), is such a fun plant to grow. Bearing the cutest little orange lanterns that are useful in dried arrangements. This plant grows from underground stolons or stems and can pop up all over the garden in a very short time.
Bee Balm (Monarda Didyma) is loved by gardeners because it really does attract bees, butterflies and hummingbirds. It really is only a problem in rich moist soil conditions. Spreading by underground shoots you need to keep a close eye on this one.
Ribbon Grass (Phalaris arundinacea ‘Picta’) is a very attractive grass with white stripes. Easily grown in most garden conditions and so invasive that I think it only belongs in the back forty, if you have a back forty. I do not recommend that this plant ever goes into a perennial border.
Tansy (Tanacetum vulgare) is a three foot herb with cute button like yellow flowers and fernlike foliage. Definitely not for the small garden. Use only if you have a large meadow.
Bouncing Bet (Saponaria officinalis) with its pretty pink flowers makes a great ground cover in the right space. Creeping by means of stolons it quickly become a nuisance in the small garden.