The perennial Tradescantia ohiensis, or Ohio Spiderwort, is common in gardens and naturalized landscapes across North America. Its rapid spread and vigorous nature often confuse gardeners, leading to questions about its classification and environmental impact. Is Ohio Spiderwort an invasive species that poses an ecological threat, or is it simply an aggressive native plant requiring management? Understanding this distinction is key to handling this common garden flower.
The Definitive Answer: Native Status
Ohio Spiderwort is unequivocally a native plant across a vast portion of the eastern and central United States, including its namesake state. Its natural range extends from southern Ontario down to Florida, and west to states like Minnesota and Texas, where it thrives in prairies, meadows, and along roadsides. Because of this extensive natural distribution, T. ohiensis cannot be classified as an invasive species within its native range. An invasive species is non-native and causes environmental or economic harm. Since Ohio Spiderwort evolved alongside North American flora and fauna, it is a natural component of these ecosystems and does not displace native species destructively.
Understanding Aggressive Growth
The perception of Ohio Spiderwort as “invasive” stems from its aggressive growth habits within a manicured garden setting. The plant forms robust clumps that expand quickly through a dense network of thick, fleshy roots and rhizomes (underground stems). This vegetative spread allows the plant to efficiently colonize nearby garden space, often leading to crowded beds. Furthermore, T. ohiensis is a self-seeder, readily reproducing from the small capsules it produces after flowering. This aggressive spread, especially in rich garden soils, leads gardeners to describe it as weedy or a nuisance. Compared to truly invasive species like the tropical Wandering Jew (T. fluminensis), the distinction is clear. While Wandering Jew smothers entire native ecosystems globally, Ohio Spiderwort simply competes with other plants in a flowerbed, a behavior common to many vigorous native perennials.
Practical Management and Control
Managing the vigorous nature of Ohio Spiderwort involves simple, routine gardening practices focused on controlling its spread. A fundamental practice is deadheading, which means removing spent flowers before they form seed capsules. This action directly prevents the plant from self-seeding and limits unwanted seedlings in subsequent seasons. Gardeners can also control lateral spread by regularly dividing the clumps, typically every few years when they become too dense. The thick root mass can be dug up and separated, allowing the gardener to replant a smaller portion or remove the excess. Placing Ohio Spiderwort in a location with ample space to naturalize, or restricting it with physical barriers like edging, can minimize its aggressiveness and reduce the need for constant intervention.