“Don’t plant a pest!”
You may wonder what the difference is between a weed and an invasive plant. Let’s just say that invasive plants are weeds, only much worse.
Weeds are unwanted plants that appear in cultivated areas. They can be either native or non-native, but they have a tendency to grow only in areas that are tended by humans. They rely on irrigation, fertilization, tilling and other horticultural interventions to survive. They generally don’t do well in natural areas that are untouched by humans.
Invasive plants can be native, but most are not. They have a tendency to escape into wild areas and take over from the native species. Once established, they will choke out native plants completely and disrupt the ecosystem. Insects and other creatures can, in turn, be choked out due to their habitat and food sources being replaced. For instance, areas that have been overtaken by giant reed no longer have songbirds because the native insects have nothing to eat, which, in turn, leaves nothing for the birds to eat.
Invasive plants can change soil fertility and salt content, erosion patterns, and water flow and retention. They can also create unnatural fire hazards. Pampas grass, once a very popular landscape plant, has the unfortunate tendency to explode into sparks when it catches fire. Thankfully, this pest grass is seldom planted anymore, but its prolific seeding habits have made it a common sight on hillsides and wild areas.
Most invasive plant species have been introduced via their use in ornamental and landscape plantings. They became popular because of their tolerance for heat, poor soil conditions, and lack of water. Unfortunately, these characteristics are what make them invasive.
What can you do, as a home gardener, to stop the spread of harmful invasive plants? The California Native Plant Society has plant lists for every climate zone in California, so start with selecting your landscape plants from their lists.
If you have a planted aquarium, never dispose of aquatic plants in local ponds, creeks or waterways. Some of the worst offenders on the invasive plant list are aquarium plants. If you want to get rid of these plants, either discard them in the regular trash or compost them in a secure bin.
The California Invasive Plant Council has an excellent website at cal-ipc.org which is updated frequently. They also suggest California-friendly alternatives to popular, but invasive, landscape plants. Here are some invasive plants and their suggested substitutes:
Invasive Ground Cover: English ivy, Highway ice plant, Vinca major.
Non-invasive Ground Cover: Ivory star jasmine, germander, San Diego marsh elder, Beach strawberry.
Invasive Grasses: Giant reed, Pampas grass, Green Fountain grass.
Non-Invasive Grasses: Deer grass, bear grass, California fescue, blue oat grass
Invasive Shrubs: Blackwood acacia, Brooms (French, Scotch, Spanish), Chinese wisteria
Non-Invasive Shrubs: Viburnum, Coffeeberry, Redberry, Lemonade berry, Cleveland sage
Have questions? Email gardening@scng.com.
Looking for more gardening tips? Here’s how to contact the Master Gardener program in your area.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; 949-809-9760; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; 951-683-6491 ext. 231; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu/
