Marin Home / GARDEN
Stamping out nonnative plants. BY KIER HOLMES
Love plants? Marin County is a stellar place to get a garden growing.
Freezing temperatures are rare, winters are short, rolling hills provide
wind protection, and it tends to rain here more than inland — all favorable
conditions for a variety of flora. Unfortunately, that variety includes
nonnative plants that can spread in your yard and neighborhood and into
our prized open spaces. Here’s advice for avoiding these troublemakers and
getting rid of the ones you find.
Definition Invasive plants are nonnative to the
ecosystem and have the potential to cause environmental or economic harm. Typically they’re
fast growers, aren’t plagued by disease or natural
predators and have many methods of multiplying.
Neighborhood Bullies Invasives win the competition against crops and native species for critical
resources like water, soil nutrients and sunlight;
plus, they endanger wildlife by forming monocultures (dense stands of one plant) that clog
waterways and raise flood and fire risk.
The Resistance While all of Marin’s natural
areas biologically try to defend against invasive
species, some have more success than others.
Over 300 documented nonnative plant species
exist on Mount Tamalpais, for example.
Stray Migration While you may be a conscious
gardener, outside actors like birds, animals, wind
and flooding can spread unwanted seeds. Check
the invasive plant list at cal-ipc.org to see what
culprits you might need to remove from your yard.
Root Them Out While the first defense against
invasives is not to plant them, there are many
ways to remove or contain them — manually
pulling, weed whacking, hoeing, mowing, tarping
and mulching — and using several methods is
best. Also research whether your intruder reproduces by seed or by root fragments; that will
determine your removal approach.
Mexican feather grass (Stipa tenuissima)
Licorice plant (Helichrysum petiolare)
Pampas grass (Cortaderia selloana)
Giant reed grass (Arundo donax)
Running bamboo (usually Phyllostachys
species but also Pseudosasa,
English ivy (Hedera helix)
Highway ice plant (Carpobrotus edulis)
Periwinkle (Vinca major)
Pride of Madeira (Echium candicans)
IN THE FIELD
“Homeowners can create
a refuge for native plants,
animals and pollinators.
Plus, if you see a plant out of
place in one of your favorite
wildland places, snap a
photo of it and submit it to
Calflora or iNaturalist; both have apps,” says Dana
Morawitz, conservation program manager for the
California Invasive Plant Council. She also suggests
volunteering with local land managers or neighbors
for strategic invasive plant removal efforts — aka
weed pulls — and subsequent restoration planting.
Pride of Madeira