A Master Gardener's Journal

Invasive plants grow aggressively, spread like wildfire and displace other plants in our ecosystem. "Most people aren't aware of the damage invasive plants are inflicting on our biodiversity, our wildlife habitat and our native plant species," says Larry Kuhns, Penn State professor of ornamental horticulture. He offers the following advice to homeowners who would like to keep invasive plants in check on or near their property...

Prevent landscape disturbance. Invasives will thrive in bare soil or tilled earth where native plants have been displaced. "One key to controlling invasives is to protect healthy plant communities," Kuhns says.

Maintenance plans. Although most homeowners regularly maintain lawns and ornamental gardens, other property areas need maintenance as well. "Meadows should be mowed at least once a year," Kuhns advises. "In woodlands, owners should walk the property and eliminate invasive plants."

Go scouting. All homeowners should inspect their land every year.

Remove invasives early. If a homeowner has been scouting vigilantly, most invasive plants can be found when they are small and easily controlled. Kuhns warns that invasives should not be allowed to go to seed. "Digging or cutting out the offending plant is preferred," Kuhns says. "But large plant populations may need to be stopped using a herbicide. Only trained professionals should apply herbicides."

Replant after weeding. Invasive plants exploit bare soil and unused niches. "If you remove a weed, the invasive plant will come right back unless you substitute another plant," Kuhns says. "It's important to fill niches with plants that will provide seeds for the future."

Ready to take on this threat to our environment? Wondering what else you can do to prevent the spread of invasives? Plenty! Here are some ideas:

Start a campaign in your neighborhood by teaching your family, friends and neighbors about the negative ecological effects of invasive species.

Use native and non-invasive plant species in your home gardens. Don't buy purple loosestrife! (Hopefully, nurseries are no longer selling it.)

Learn more about non-invasive alternatives, how to control specific invasive plants, and selecting native plants.

Call our Master Gardener hortline to find out how to remove invasive plants from your landscape.

Prevent invasive plant seed spread by deadheading their flowers.

To get you started on your efforts to eliminate invasives from your property, here's a list of the ten invasive plant species most commonly found in Pennsylvania:

Tree of heaven
Autumn olive
Multiflora rose
Purple loosestrife
Japanese knotweed
Common Reed
Canada thistle
Poison hemlock
Japanese stiltgrass
Mile-a-minute vine

Do you have a gardening question? In Delaware County, call our Master Gardeners hortline at 610-690-2671 on Tuesdays and Thursdays from 9 AM-12 NOON.

UPCOMING MASTER GARDENERS EVENTS

Registration required for all events. Please call 610-690-2655 for more information or visit our website