Plants like ivy and trumpetvine might appear to provide good shelter for wildlife, since they grow quickly and are dense enough to protect small animals from predators. However, these plants are not native to Santa Barbara, and their aggressive growing habits can enable them to take over large areas in your backyard and beyond. Native plants are usually better options- after all, animals thrived in our area before the nonnative plants were introduced.
What makes a plant invasive?
An invasive plant is a nonnative plant that spreads vigorously and is difficult to control. Invasive plants can harm ecosystems by choking out the native vegetation and taking over the area. Many invasive plants will also suck water out of the surrounding soil, which is not good in an area like Santa Barbara that is prone to drought.
Are all nonnative plants invasive?
Many nonnative plants, like Italian buckthorn and pittosporum, are not invasive and work well in backyards. However, native plants tend to be more desirable to wildlife. Many produce berries or other parts that native animals (especially birds) eat, and some are host plants for native butterflies and moths.
Are denser plants always better as wildlife cover?
Some animals do prefer heavier vegetation. For example, songbirds often sleep perched in bushes with thick foliage so that they are not easily preyed on. However, plants like this also attract rodents, which can cause problems if their population is too large. In general:
- Freestanding bushes will not attract as many rodents as invasive vines like ivy.
- Dense vegetation is best planted away from your house in case rodents take up residence.
In addition to providing dense vegetation for birds and other small animals, it's good to provide more open bushes or trees with strong branches for cat-sized animals (skunks, raccoons, and opossums) to hide in. The habitat value of these bushes and trees can be increased by planting tall grasses or low-growing shrubs around them to provide extra cover.
Should any plants be avoided at all costs?
Some invasive plants can be used sparingly in a landscape and maintained, but some should be avoided altogether. One of the worst ones is Arundo donax. Commonly known as arundo or giant cane, this plant is very hard to control and is a major problem in local creeks. It can provide cover for some wildlife, but it also crowds out native plants that provide food to animals, causes erosion and flooding in creeks, uses a lot of water, and is extremely difficult to remove. In addition to this, if you live near a riparian area or other ecosystem with trees and moisture, avoid planting invasive vines such as trumpetvine that can take over an area rapidly in the right conditions.
What should I plant instead?
There are many native plants that can be used to replace nonnatives. Roger's Red wild grape, for example, is a good alternative to invasive vines, and a variety of native tall grasses like ryegrass, deer grass, and Berkeley sedge are available to replace invasive ones like Mexican feather grass. Nonnative but not invasive bushes like pittosporum and buckthorn can still be planted and may provide wildlife cover, but would best be replaced by native ones like lemonade berry and ceanothus.
A good starting point when looking for plants is the City of Santa Barbara's online searchable database. This tool allows you to search by plant characteristics like height and sun requirements, and provides basic information about many drought tolerant plants. Note that not all the plants in the database are native or provide good wildlife cover. (The Skunk Corner is not affiliated with the City of Santa Barbara.)