'Burkwoodii' reaches between 5 and 7 feet tall, with crimson flowers in late spring.

'Killiney Red' is a smaller, compact variety with red blooms. 'Goldfinch' is crimson and yellow with pink and yellow wings. 'Cornish Cream' has ivory cream and yellow flowers.

There are several cultivars of the species.

Cytisus scoparius (common broom, Scotch broom) puts on a long show of yellow flowers on its 5-foot reach from May to June.

Cytisus x praecox (Warminster broom) is a hybrid that grows to 5 feet tall offering pale yellow flowers in early May.

Foliage is deep green and flowers are ruby red and yellow through spring and early summer.

Cytisus x 'Lena' (Lena scotch broom) a dwarf variety that grows 4 feet tall.

Cytisus x spachianus (sweet broom) is a hybrid with bright yellow, sweetly fragrant flowers in late spring.

This wide, low-growing shrub displays pale yellow to creamy white flowers in spring.

Cytisus x kewensis (Kew broom) reaches 2 feet tall and is ideal for rock gardens.

The Spruce Home Improvement Review Board.

Gardening hangovers, Part 2: Mexican fan palmsįandom awaits: Join our Facebook page for California gardeners. Gardening hangovers, Part 3: fountain grass To find alternatives to invasive garden plants, check these websites:, , and. “If we can prevent people from planting these weeds, that’s money the Park Service can spend on other things - interpretative and education programs - things that people are excited about.” So land managers such as Brigham could be weeding indefinitely, and scrambling to pay for it. He estimates some 5 million California homes are within a few miles of a wildland, creek or park. “It’s ridiculous to think nurseries would ask every customer how urban they are and base their sales on our response,” says invasive plant educator Drew Ready, “It just won’t happen.” For instance, Staddon argues some of the especially useful runaways should be allowed in “highly populated areas where they will never have the opportunity to become invasive.”

Gray areas and divergent perspectives cloud consensus efforts. Some weeds are also hybridizing in the wild, making identification difficult. Research suggests pampas grass cultivars that seem sterile in nurseries are nevertheless contributing pollen to feral populations, helping them spread. Scientists know that some species of broom, pampas grass, and ivy are invasive, but which of their cultivars threaten wildlands is unclear. “The issue has been bewildering for the industry,” says Craig Regelbrugge, a vice president at the American Nursery and Landscape Assn., because some invasive plants vary regionally and “the science is fast evolving.” And other companies continue to sell about 30 of the state’s worst weeds. Staddon keeps a wary eye on new imports: “I’ve learned to look for certain traits in plants that could mean they’ll become invasive.”īut Monrovia offers Spanish broom and Mexican fan palm on its website, which doesn’t identify them as potentially weedy. The company’s computer system won’t allow salespeople to ship invasive plants to regions where they threaten wildlands, according to Nicholas Staddon, director of new plants. Azusa-based Monrovia Growers, a member of Cal-HIP, has replaced many runaway plants with less aggressive alternatives.

Yellow spanish broom