Spider plants, commonly kept as houseplants, are showing strong growth outdoors in Napa County, according to local gardeners. The variegated variety is often recognized for producing new plantlets and small white flowers at the ends of long stems. Some residents have reported success in allowing spider plants to naturalize in shaded garden areas.
Penny Pawl, a UC Master Gardener of Napa County, shared her experience: several years ago she moved her spider plant outdoors due to an abundance of indoor plants. Placed under a redwood tree, the plant’s long stems rooted into the soil and began spreading. Even after relocating the original pot, these rooted stems continued to grow and form ground cover without additional watering or fertilizer.
Another non-variegated spider plant has established itself elsewhere in her garden with no clear origin. “I don’t irrigate or feed any of these plants, yet they are thriving in semi-shady areas,” Pawl said.
The spider plant (Chlorophytum comosum) is native to Africa but has spread globally, including regions like Western Australia and Bangladesh. It originates from climates that experience months of dryness each year and can survive on winter rainfall alone in Napa County gardens. “They compete with the redwoods for water, but that does not seem to stop their growth at all,” Pawl noted.
Spider plants have dense root systems capable of storing water. When grown in containers indoors, they require occasional watering—about once a week—and benefit from pots slightly larger than their root balls for expansion. Outdoors, especially under large trees such as redwoods that may offer frost protection, these plants can persist even through occasional cold snaps.
Belonging to the asparagus family along with hostas—despite differing needs—the spider plant is also known by names such as airplane plant, ribbon plant and spider ivy. It grows well outside within USDA Plant Hardiness Zones 9 through 11 but acts as an annual where winters bring frost.
For those interested in propagation: “Now that your plant is growing beautifully, what to do with all those pups? Look at them closely and you’ll see their baby roots,” Pawl explained. These young offshoots can be transplanted into new containers or shared with others.
UC Master Gardeners of Napa County will hold a free online talk titled “Healthy Soil = Healthy Plants” on Thursday, March 5 from 7 pm to 8 pm via Zoom. The event will discuss how soil health affects plant problems and possible solutions; registration is available through this link: Register here to get the Zoom link .
Gardeners seeking advice can contact the Master Gardener Help Desk using an online form or by emailing mastergardeners@countyofnapa.org. In-person visits are welcome on Mondays and Fridays between 10 am and 1 pm at the University of California Cooperative Extension Office located at 1710 Soscol Avenue, Suite 4, Napa.
