Invasive Plants
Creeping Bellflower (Campanula rapunculoides)
Much has been written about invasive plants, but what exactly are they? Just because a plant is aggressive does not mean it is invasive. For instance, that creepy looking, vining wild cucumber, Echinocystis lobata, that winds through plants and trees along the roadsides in late summer is aggressive, but is actually a native plant.
Native plants have been here for an extended period of time, are adapted to local climate and ecosystems. They typically require little input, are beneficial to pollinators, are competitive without being weedy, and can be ornamental. On the other hand, invasives were imported, sometimes years ago. They outcompete the native plants for resources, negatively disrupt ecosystems, and many are toxic. Unfortunately, the list of invasives is long and some of them have gotten a strong foothold in the environment.
Individual residents can get involved and have a huge impact in controlling these invasives. The first step is becoming educated about what plants are designated as invasive. Unfortunately, some of them are quite attractive which has led some homeowners to unknowingly plant them. The University of Wisconsin Extension Renz Weed Science Lab has a list of more than 38 of the more common plants, including factsheets with identification and management tools. Those can be found at this link: https://renzweedscience.cals.wisc.edu/resources/invasive-management-factsheets/ Mechanical, cultural, and chemical control methods are all give in detail, including appropriate timing, which in many cases is the key to control.
Once identified, the next step is to diligently remove the invasive. This can be a dauting task with some of the more persistent plants like buckthorn or some of the more toxic plants like wild parsnip. It may take repeated attempts and several years to be successful, but the long-term benefits cannot be overstated.
Once the invasive is under control, the next step is to replace it with something better for the environment. Native plants are always a good choice. Any gardener knows that care must be taken to match the plant to the location, light, water, and soil conditions. A “right plant, right place” philosophy will yield the best results. A soil test will help with this determination and is always a good first step. There are native plants available in all categories from trees to grasses to herbaceous ornamentals.
Once again, timing is a critical component when establishing the new planting. Some native seeds must undergo a cold period and need to be planted in the fall; others should be planted in the spring. Using transplants means that spring planting is the best time to get started. Use a reputable nursery for all plant selections.
Many people think that native plantings are messy and untidy. However, this is often false. With planning and care, a native garden can be as manicured as the gardener wishes. Deadheading, pruning, and weeding all take time, but they will ensure a beautiful and tidy garden. Don’t be afraid to mix in some annuals to fill in empty spaces and perk up the down times. Just be sure to stay away from any that might be prone to self-seeding and become a problem in subsequent seasons.
An additional benefit to native gardens is that they provide food and shelter for pollinators and wildlife. Once established they require little care and will not be the headache that invasives have caused to the environment.
Carol Shirk
Certified Master Gardener