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El Dorado County Invasive Weed Management Group
 

• A Builder and Contractor's Guide to Preventing the Introduction and Spread of Invasive Weeds
• A Landowner's Guide to Preventing the Introduction and Spread of Invasive Weeds
• Selected Invasive Weeds of the Central Sierra Nevada - A Field Guide - 4th Edition April 2007
• Don't Plant a Pest Brochure - Sierra Foothills Region
• Please Don't Plant A Problem! An invasive weed to watch for: Oblong Spurge Brochure

Invasive Weed Priority List - El Dorado County Invasive Weed Management Group - March 2009

Group 1 - These terrestrial species are: a) not currently found in El Dorado County, or b) documented as small, eradicable populations, or c) deemed controllable along a defined eastern leading edge to prevent spread into the Sierra Nevada Mountains. Encourage active control/eradication efforts and education in El Dorado County.

• Yellow starthistle (Centaurea solstitialis); eradicate at 3500 ft. elevation and higher
• Spotted knapweed (Centaurea maculosa)
• Tall whitetop/perennial pepperweed (Lepidium latifolium)
• Dalmatian toadflax (Linaria genistifolia ssp. dalmatica)
• Oblong spurge (Euphorbia oblongata)
• Tamarisk/saltcedar (Tamarix spp.)
• Scarlet wisteria/rattlebox (Sesbania punicea)
• Purple loosestrife (Lythrum salicaria)
• Canada thistle (Cirsium arvense)
• Diffuse knapweed (Centaurea diffusa)
• Rush skeletonweed - control at 3500 ft. elevation and higher (Chondrilla juncea)
• Hoary cress (Cardaria draba)
• Lens-podded whitetop (Cardaria chalepensis)
• Purple starthistle (Centaurea calcitrapa L.)
• Russian knapweed (Acroptilon repens)
• Stinkwort (Dittrichia graveolens) - eradicate at 3500 ft. elevation and higher
• Yellow toadflax (Linaria vulgaris)
• Giant knotweed (Polygonum ssp.)
• Sicilian starthistle (Centaurea sulphurea Willd.)
• Meadow knapweed (Centaurea debeauxii ssp. thuilierii)
• Dyer's Woad (Isatis tinctoria)
• Tocalote/Malta thistle (Centaurea melitensis)

Group 2 - Encourage the management/control of isolated populations of these terrestrial species to prevent further spread in El Dorado County.

• Brooms (Scotch - Cytisus scoparius, French - Genista monspessulana and Spanish - Spartium junceum)
• Arundo/Giant reed (Arundo donax)
• Fennel (Foeniculum vulgare)
• Goatgrass (Aegilops triuncaialis)

Group 3 - Other terrestrial species of concern; continue to increase public awareness and encourage control efforts on public and private lands.

• Tree of Heaven (Ailanthus altissima)
• Himalaya blackberry (Rubus discolor)
• Puncture vine (Tribulus terrestris)
• Pampasgrass (Cortaderia selloana)
• Johnsongrass (Sorghum halepenses)
• Yellow sweetclover (Melilotus officinalis (L.) Lam.
• White sweetclover (Melilotus alba Medic.)
• Medusahead (Taeniatherum caput-medusae)
• Italian thistle (Carduus pycnocephalus)
• Hedge parsley/Beggar's lice/Velcro stickers (Torilis arvensis)
• Bull thistle (Cirsium vulgare)
• Klamathweed (Hypericum perforatum)
• Yellow starthistle (Centaurea solstitialis); encourage control below 3500 ft. elevation
• Big Periwinkle (Vinca major)
• Cheatgrass, Downy brome (Bromus diandrus)
• Gorse (Ulex europaeus L.)

Watch List - These terrestrial species are under consideration to be added to the Invasive Weed Priority List; more information is needed to evaluate their invasive characteristics and/or ability to growing in western El Dorado County.

• Rose campion (Lychnis coronaria)
• Tree tobacco (Nicotiana glauca)

Aquatic weeds to watch for:

• Hydrilla (Hydrilla veticillata)
• Sponge plant/smooth frogbit (Limnobium laevigatum)
• Eurasian watermilfoil (Myriophyllum spicatum)