What is an invasive plant? What’s the problem?

Most of the plants used in gardens and landscaping do not invade or harm wildland areas. But a few species escape into wild landscapes, and become a problem. When an aggressive plant is introduced to a new environment, the factors that would normally limit their growth in their native range may not be present. This allows them to proliferate, spread, and take over ecosystems. Invasive plants are non-native, can spread on their own, and cause or are likely to cause environmental or economic harm.

When invasive plants spread, they can crowd out native plants, increase wildfire and flood danger, clog valuable waterways, degrade recreational opportunities, and destroy productive range and timber lands. Invasive plants can radically alter ecosystems, creating a domino effect that harms all types of native wildlife.

Why invasive plants are a problem

Plants to Avoid

PlantRight has identified seven priority invasive plants that are sold for ornamental use in California. We urge all California homeowners, landscapers, and other plant buyers to avoid these seven plants for use in regions of California where they are invasive. We are working with California’s nurseries and garden centers to eliminate these plants from circulation and promote non-invasive alternatives.

See the priority invasive plants

Success stories: the retired plant list

With the help of retailers, growers, and landscaping professionals, several invasive plants have largely been phased out of California’s supply chain and replaced with non-invasive alternatives. Because these invasive garden plants are rarely sold at retail, we have “retired” them from our PlantRight List.

The retired invasive plant list

How do you decide which plants are high risk?

The plants on our invasive plant list are selected using two primary tools: the Plant Risk Evaluator (PRE), a method for determining a plant’s potential for becoming invasive in any specific region; and PlantRight’s annual Spring Nursery Survey, which tells us which potentially invasive plants are for sale, in which regions, and at how many locations. Together these tools help us determine which plants are the biggest risks to California’s ecosystem. The final decision to include a plant on the list is made with our Plant List Committee and Steering Committee.

Learn more about our process

How does Planting Right help?

Most invasive plants have been introduced as decorative plants, used in yards, gardens, and outdoor spaces. Because they are selected for their looks, they have often been introduced without considering the effects on the local ecosystem.

Planting Right is about knowing which decorative plants are likely to cause problems and avoiding those plants in favor of attractive and appropriate non-invasive plants. For every invasive plant, there are usually several non-invasive plants that look similar, grow in similar areas, and fulfill similar aesthetic roles in a garden or other outdoor space. When you select one of these alternatives instead of an invasive plant, you’re protecting the local environment against the many problems that invasive plants can cause.

PlantRight created this website to help people know which plants to avoid and what some of the many better alternatives are.

How to Plant Right