Can You Grow Sweet Woodruff in California?

Plant Hardiness Zones

• Sweet woodruff thrives in U.S. Department of Agriculture plant hardiness zones 4 through 9. California's plant hardiness zones range from 4a in a few areas in the Sierra Nevada mountains, on the eastern edge of the state, to 10a and 10b along the coast and in southern California. While it won't grow in the desert regions of the state without special care, in general, California's climate is suitable for sweet woodruff.

Sun or Shade

• In the cooler climate along California's coast, sweet woodruff thrives in sun or shade, but in warmer climates it prefers partial to full shade. This groundcover is particularly suited to woodland gardens, filling in under trees with green foliage. It blooms in April and May, providing numerous small white blossoms to brighten the spring garden. Sweet woodruff is unaffected by juglone, making it one of the few plants that thrive in the shade of a walnut tree. Juglone is a toxic substance that inhibits plant growth, produced by the black walnut tree and in lesser amounts by its close relatives, the butternut, pecan and English walnut.

Soil

• While sweet woodruff is not fussy about soil type and pH levels, it tends toward invasiveness when planted in moist, rich soils. Planting it in heavy clay soil helps slow the plant's rapid growth. To keep it under control, avoid amending or fertilizing the soil. If it's necessary to knock sweet woodruff back, you can mow the 6- to 12-inch-tall plants using the mower's highest setting.

Water and Fertilizer

• Sweet woodruff thrives in cool, moist but not waterlogged locations. To encourage rapid growth, water when the soil is dry to the touch. Adding a layer of mulch over the soil helps maintain a consistent moisture level, slowing the rate of water evaporating from the garden bed. Fertilize the plants once in the spring, when the new leaves begin emerging, by mixing 1 tablespoon of 10-10-10 fertilizer per gallon of water and applying to each plant. Water before and after fertilizing to protect the plants' tender roots from the fertilizer salts.