Western sycamore, Platanus racemosa, is a statuesque deciduous tree found in riparian areas and dry washes. It is almost always found in wetland-riparian settings such as stream sides and moist canyon bottoms and its range extends from the northern Central Valley to coastal San Diego County and Baja California. However, there are only a few known trees in Solano County and Yolo County.
Thus, Western sycamore is a component of or adjacent to a wide variety of different communities: chaparral, foothill woodland, valley grassland and riparian.
In this series, we have compiled a short list of compatible native plants you can consider in developing a native plant garden around your Western Sycamore. Native plant species are grouped by form: grasses and bulbs, wildflowers, short/small perennial plants and shrubs, tall perennial shrubs, spreading ground covers. All of those listed are available at native plant nurseries and/or California Native Plant Society sales. CalScape is an excellent reference to use for learning about and locating plants to buy.
When evaluating your plant palette, consider native species that can handle mixed sun and shade.
Grasses and Bulbs: Douglas iris (Iris douglasii). Grasses and sedges including Elymus and Carex. Brodiaea’s and similar spring bulbs, as well as Soap plant (Chloragalum pomeridianum).
Wildflowers: Columbine (Aquilegia formosa), California Fuchsia (Epilobium spp.), Alumroot or Coral Bells (Heuchera spp), Rooreh, which was formerly known as miners’ lettuce (Claytonia perfoliata).
Small perennial plants and shrubs will thrive along the canopy’s edge. Included in this group are yarrows (Achillea species), coyote mint (Monardella sheltonii), Hummingbird Sage (Salvia spathacea), and Mugwort (Artemisia douglasiana). This is a good location for snowberry (Symphoricarpus albus) and creeping Oregon grape (Berberis aquifolium var repens).
My many favorite tall shrubs: Fragrant pitcher sage (Lepechinia fragrans), California Wildrose (Rosa californica), Spice bush (Calycanthus occidentalis), western redbud (Cercis occidentalis) and bush anemone (Carpenteria californica).
Spreading Ground covers: wild strawberries (Fragaria), California fuchsia, hummingbird sage, shorter-growing varieties of Yarrow (Achillea millefollium) and coyote mint (Monardella species), wild grape (Vitis californica).
Would you like online help with a plan? https://bayarea.calscape.org/wp-content/uploads/2022/10/111022_Woodland-1.pdf
Resources
https://waterwisegardenplanner.org/garden-styles/western-sycamore/