The primary way invasive plants enter the park is accidentally. Mud and seeds can carry invasive plants. Help stop the spread by cleaning your shoes before and after your hike. START with clean gear and shoes.Use a boot brush to completely remove seeds and plant parts.STAY on the marked trails to limit spread.END with clean gear and shoes. Use a boot brush to clean off any seeds, burrs, and dirt picked up and dispose of them properly after your visit.
Habitat Restoration
To ensure the prosperity of Cabrillo National Monument’s unique coastal sage scrub habitat, park staff and volunteers work to mitigate the effects of nonnative plants through species identification, monitoring, and removal. Methods used at Cabrillo include mechanical, cultural, chemical, and manual techniques. Each method comes with its own pros and cons, but the most favorable is manual. By hand-pulling invasive plants we can remove both debris and roots. Through control of invasive plants, the native plant species have an increased chance of survival.
Invasive Plants
Executive Order 13751 defines an invasive species as, “a non-native organism whose introduction causes or is likely to cause economic or environmental harm, or harm to human, animal, or plant health.” Invasive plants decrease the biodiversity of our park’s entire ecosystems by outcompeting the native plant population for food, water, sunlight, and space. Decrease in native plants affect the survivability of native insects, animals, and birds who rely on these plants for food, shelter, and other resources. Invasive plants can also affect the chemical composition of our soil and result in poor dirt quality. Non-native plants, especially grasses, are more susceptible to fire due to their dryness and ability to spread quickly.
The National Park service Volunteers in Park (VIP) program supports the work of restoration with work crews from different organizations and through the Weed Warrior program. You too can support this work by contacting:CABR_volunteers@nps.gov.
Atriplex glauca Waxy Saltbush
(Europe)
Flower Mar-Jul
12”-4’ Perennial, round shrub, yellowish purple stems, small waxy wavy edged grayish green oval leaf, whitish pink flower on drooping stalk
Atriplex semibaccata Australian Saltbush
(Australia)
Flower Apr-Dec
6” Perennial, viny yellow stemmed, wavy edged gray leaf, red seed producing berry, often spread up and through neighboring plants
Chenopodium album Goose foot
(Europe, Asia, Northern Africa)
Flower all year
< 3’ Annual, usually single reddish green thick sturdy stem, triangular-shaped short pointy edged leaf ≤ 2”, tiny disk-shaped seed, has strong cabbage odor
Audubon.org
Erigeron bonariensis Horseweed
(South America)
Flower all yea
r≤ 36” Annual, hairy erect stem, hairy blue-green narrow jagged edged leaf ≤ 4”, small white flower, wind-blown seed, topmost leaves appear wrinkled and scrunched
Erodium cicutarium Stork’s Bill
(Mediterranean)
Flower Feb-Sep
12” Annual, basal rosette, reddish stem, broad dark-green leaf divided into little lobed leaflets, purple flower, light green pointed stork’s bill shaped seed, seed head dries to corkscrew shape that bores into ground when wet
Euphorbia maculata Spotted Spurge
(Eastern North America)
Flower Apr-Oct
< 2” Annual, growing flat to ground, thin red stem, oval-shaped leaf with red spot in middle of most leaves ≤ 0.5”, when stem breaks can ooze white sap
Glebionis coronaria Crown Daisies
(Mediterranean)
Flower Mar-July
≤ 5’ Annual, usually single thick green hairy stem, bright green broad leaf splitting into spindly thin lobes, yellow or white ray petals with yellow center ≤ 2.5” flower
Hedypnois rhagadioloides Crete Weed
(Europe and Asia)
Flower Feb-Jun
4”-12” Annual, low growing hairy many stemmed rosette, jagged edged green ≤ 6” leaf, yellow ray petaled ≤ 1” flower with dark coloration on tips, seed head looks like tiny basket
Avena barbata Wild Oats
(Eurasia)
Flower Mar-Jun
< 6’ Annual, light green thick base grass gradually thinning upward, light green cocoon-like seed dangle from top
Hordeum murinum Hare Barley
(Mediterranean)
Flower Feb-May
< 3’ Annual, dull green grass, thin flimsy stem, spiky slightly flattened pale green flower head with long skinny awns, like Bromus rubens
Lamarckia aurea Toothbrush Grass
(Mediterranean)
Flower Feb-May
< 8”Annual, pale green soft grass, cream-colored delicate side hanging flower head, bristle-shaped downward drooping seeds
Polypogon monspeliensis Rabbit’s Foot
(Southwestern Europe)
Flower Apr-Aug
< 3’ Annual, blue green round stemmed grass, soft fuzzy light green round flower head, flower and seed head look like rabbit’s foot
Lysimachia arvensis Scarlet Pimpernel
(Europe)
Flower Mar-May
<1’ Annual, growing close to ground, slender green stem, oval-shaped green leaf with pointed tips ≤ ¼”, 5 petal flower with pink at base
Malephora crocea Coppery Mesembryanthe-mum
(South Africa)
Flower Mar-Dec
≤ 8” Succulent, finger like reddish green leaf <3”, yellow orange red flower, name “coppery” references leaf and flower color
Malva parviflora Cheese Weed
(Northern Africa, Europe, Asia)
Flower Mar-May
6”-7’ Annual, single to many stemmed, green tough stem, heart-shaped 5-7 lobed crinkled edged fuzzy leaf, pinkish white 5 petal flower ≤ 0.5”, seed look like green cheese wheel cut into wedges
Medicago polymorpha Burr Clover
(Mediterranean, Europe)
Flower Mar-Jul
≤ 5” Annual, spreading dark reddish green stem matt, 3 folded dark green leaflets, bright yellow ≤ ¼” flower, gray black ≤ ¼” burr fruit, burr sticks to everything
Melilotus indicus Sweet Yellow Clover
(Eurasia)
Flower Apr-Oct
< 24” Annual, usually single skinny erect stem, green compound leaf with three leaflets, 2” flower head of tiny yellow flowers surrounding stem, tiny ball like seeds at end of stem
Mesembryanthe-mum crystallinum Crystalline Iceplant
(South Africa)
Flower Mar-Oct
≤ 8” Succulent, reddish-green thick crinkled leaf ≤12” in diameter, thin white ray petal yellow centered flower, seed present in red bulbous head, salt “crystals” cover entire plant
Mesembryanthe-mum nodiflorum Slender-Leaf Iceplant
(South Africa)
Flower Apr-Nov
≤ 8” Succulent, reddish green small round slender leaf, small frilly white flower with yellow center, star shaped seed head
Oxalis pes-caprae Bermuda Buttercup
(South Africa)
Flower Jan-May
≤14” Perennial, bright green many stem, three heart-shaped leaflets green clover shaped leaf, bright-yellow 5 petaled ≤ ½” flower on upright stem, alt name Sour Grass
