Many of the characteristics that make a plant Gardening green an attractive choice for the garden may also make it a successful invader: California is a gardener’s dream. Our mild climate Don’t allows us to have fantastic gardens, showcasing a wide Garden Plants: Invasive Plants: variety of ornamental Easy to propagate Broad germination plants from all around Establish rapidly Colonizer the world. Mature early Mature early Abundant flowers Prolific seeds plant a But sometimes, our Pest/disease tolerant Few natural predators garden plants “jump the fence” and invade Invasive plants are by nature a regional problem. A natural areas. These plant that jumps out of the garden in one climate and invasive plants can habitat type may behave perfectly in another. The become serious wildland twelve problem plants listed here have escaped from pest! weeds that threaten gardens throughout the greater Bay Area. California’s biodiversity and economy. How to use this brochure: This brochure suggests safe alternatives for these More than half of the plants. When you are buying new plants, consider these Give them an inch and plants currently Conservancy Nature The Rice, Barry alternatives, or ask your local nursery for other damaging California’s French broom invades Bay Area hillsides non-invasive plants. If one of the invasive plants is wildlands were originally introduced for landscaping already in your yard, especially if you live near they’ll take an acre... purposes. Garden escapes like pampasgrass and Scotch wildlands, you may want to remove it and replace it broom may have desirable characteristics in a garden with a recommended alternative. setting, but outside the garden these plants displace native species and alter natural processes. Think about why you might plant one of the problem plants in the first place. Is it for the way it looks? If Some of these plants show weedy tendencies in the so, finding a replacement is often easy—some of the garden as well. For example, English ivy can take over alternatives listed here are selected especially for their a yard and similar appearance. Or maybe you need a plant to fill damage build- a functional role, such as a ings and fences. groundcover that grows well Full sun Likewise, when in a shady place, or a border Part shade birds drop seeds plant that likes full sun. near a stream, Alternatives listed here thrive Full shade English ivy can in the same environments Drought tolerant take over native as problem plants while Low water vegetation and offering added benefits such degrade wildlife as attracting wildlife. Many of Moderate water Brianna Richardson Brianna John Randall, The Nature Conservancy John Randall, these alternatives are readily habitat. Regular water A dense stand of pampasgrass (Cortaderia selloana), Invasive ivy covers forest understory vegetation available, though others may a garden plant that has invaded California wildlands be easiest to find in specialty High water Gardeners don’t plant invasive species intentionally. or native plant nurseries. Like other Californians, gardeners have a deep respect Suggested alternatives for invasive for our state’s rich natural heritage. The good news is Both native and non-native plants have been recommended as alternatives that most garden plants behave perfectly well in their in this brochure. Care has been taken to ensure that none of the recom- garden plants of the greater mended non-natives is invasive in the San Francisco Bay Area. However, intended roles. By choosing suitable replacements for plants can adapt over time, and there is no guarantee that some of these the few problem plants, we can save ourselves trouble plants will not themselves become pests in the future. If you notice one of San Francisco Bay Area these alternatives invading natural areas, notify Cal-IPC. Pay close attention and expense in our garden and help to protect the to plant names, since a few of our recommended plants may have invasive natural California landscape at the same time. relatives­­—even in the same genus. Shrubs Shrubs, cont’d Shrubs, cont’d cornelian-cherry dogwood Don’t Plant: Don’t Plant: (Cornus mas) A small tree that produces bright scarlet wisteria broom (Scotch, French, Span- yellow flowers, which (Sesbania punicea) ish, Portuguese) become bright red, edible Birds spread the fruits of (Cytisus scoparius, Genista berries that birds enjoy. this small tree or shrub away monspessulana, Spartium Leaves may turn red and from urban plantings. It purple in fall. forms dense thickets along junceum, C. striatus) Missouri Botanical Garden Botanical Missouri streams, impacting riparian These four brooms have habitat. invaded over one million acres in California. The Japanese kerria flowers produce thousands (Kerria japonica) John Randall, The Nature Conservancy Nature The Randall, John of seeds that build up Bob Case Golden yellow flowers first appear in the soil over time, in spring on this graceful shrub, creating dense thickets that can obliterate entire plant and continue into summer. Stems Try Instead: communities. Brooms also create a serious fire hazard. remain bright green in winter after leaves fall. Note: “Sweet broom” (Cytisus spachiamus or Genista Brazilian flame bush racemosa) is not known to be invasive. However, Monrovia (Calliandra tweedii) because we lack information on its potential for © A small tree or shrub with invading wildlands, we do not recommend it as a leaves similar to scarlet subsitute for other brooms. wisteria, and bright red golden currant flowers that attract (Ribes aureum) hummingbirds and bloom all A California native, this and Information Center, UC Davis Center, Information and Ornamental Horticulture Research Horticulture Ornamental summer. shrub has a profusion of bright yellow flowers that Try Instead: turn into edible berries crape myrtle suitable for jams and forsythia jellies. Birds and (Lagerstroemia species) (Forsythia x intermedia) 1999 California Academy of Sciences Academy California © 1999 butterflies love this plant. Orr and Margaret Thomas Robert Dr. This popular tree Often the first plant to features lovely peeling bloom in spring, forsythia bark and large clusters of produces an astounding showy flowers in white, display of bright yellow Jerusalem sage pink, purple, and red. flowers. Dozens of (Phlomis fruticosa) Has Monrovia Dwarf varieties available. © cultivars are available. bright yellow flowers and Monrovia Grows quickly. © gray-green, textured leaves. gold medallion tree (Cassia leptophylla) Brilliant yellow flowers grace this winter jasmine tree throughout the summer, becoming attractive seed (Jasminum nudiflorum) pods similar to those of scarlet wisteria. Larger than Arching green stems and Joy Creek Nursery Creek Joy Sesbania, up to 25 feet tall. bright yellow flowers that © bloom in winter characterize shrub hypericum showy island snapdragon this deciduous shrub. (Hypericum ‘Rowallane’) Produces bright yellow flowers (Galvezia speciosa) A California native, this shrub has through the summer and fall. Tolerates poor soil. arching branches that reach up to eight feet tall. Arboretum Park Washington Produces copious red flowers that are irresistible to hummingbirds. Shrubs, cont’d Shrubs, cont’d Shrubs, cont’d San Diego sedge pineapple guava Don’t Plant: (Carex spissa) This large sedge has a form similar to (Feijoa sellowiana) that of an ornamental grass. Produces gray leaves This evergreen shrub has scarlet and pampasgrass to five feet tall and yellow, grass-like flowers in the white flowers, as delicious as they (Cortaderia selloana) spring. are beautiful, and waxy blue-green Though a grass, grows to size fruits with a minty-pineapple flavor. of large shrub. Wind can It is easily shaped into a small tree. carry the tiny seeds up to Bigelow’s bear grass 20 miles. The massive size of each pampasgrass plant (Nolina bigelovii) This agave can be mistaken for Monrovia with its accumulated litter a large bunchgrass. Grows up to six feet tall, © reduces wildlife habitat, producing large, striking, white flowers in summer. limits recreational 2003 Richardson, Brianna strawberry tree opportunities in conservation (Arbutus unedo) areas, and creates a serious fire hazard. Don’t Don’t plant: Plant: A gorgeous evergreen tree available in compact, shrub-like varieties that are easy to grow. It produces cotoneaster masses of beautiful white flowers, Try Instead: (Cotoneaster lacteus, and textured, strawberry-like C. pannosus) fruits. Cape thatching reed Birds have spread the Monrovia berries and seeds of these © (Chondropetalum tectorum) specimen shrubs to many This decorative, different habitats. With “grass-like” their rapid growth and plant produces competitive roots, sandankwa viburnum Monrovia attractive © cotoneasters can displace (Viburnum suspensum) flowers that native plants. This evergreen shrub are ideal in cut produces tight clusters of flower small, waxy, pinkish-white arrangements. Try Instead: flowers that give way to Grows three to bright red berries. Several © Monrovia four feet tall. compact varieties are avail- toyon able. Lindheimer’s muhly grass (Heteromeles arbutifolia and cultivars) (Muhlenbergia lindheimeri) This California native is an evergreen shrub that This large, dependable, and showy ornamental grass produces delicate white flowers and large clusters IFAS Extension IFAS Courtesy Mark Shelby, University of Florida- University Shelby, Mark Courtesy has blue-gray foli- of brilliant red berries that birds love. © age and flowering spikes in the fall and winter.