The Mountain Gardener: Deer and poisonous plants

It’s July already, and plants are growing like there’s no tomorrow. The hummingbirds are my constant companions in the garden, and the resident deer population comes by daily. There are two spotted fawns who now accompany their mother, along with a couple of her sisters. Life is good.
I see the fawns sampling plants that the older deer try. There are native plants that are poisonous for us, but only some of them are avoided by deer. It got me thinking: How do deer eat poisonous plants without apparent ill affect? 
Deer are browsers. They thrive on a mixed diet. You’ve seen them eat a few roses, then saunter over to the abutilon and then mosey on to the daylily flowers.
Deer will eat almost anything, even plants with a strong scent, like catmint, lavender and thyme, when they are hungry or need water. They can even eat a few bites of various toxic plants, according to Tom Hanley, a wildlife biologist with the Forest Service Pacific Northwest Research Station.
“There seems to be threshold levels for the toxicity of different plants, and as long as deer eat below that threshold, they’re OK,” Hanley said.
Plant toxicity varies with the time of year, too, and flowers may be less toxic than leaves or roots. They just mix it up.
That explains the eating habits of deer, but what about us?
Many of us include native plants in our landscapes to attract wildlife and save water and resources. But some of them can be poisonous.
Here are some common native plants that you should be aware of if you have small children because of toxicity. This list comes from Borstein, Foss and O’Brien’s “California Native Plants for the Garden.”
– Coffeeberry: leaves, berries and bark
– California buckeye: all parts (poisonous to bees, too)
– Western azalea: all parts
– Elderberry: all parts except ripe berries and fruit
– Solanum: all parts
– Snowberry: berries
– California buttercup: juice of the plant
– Berberis: roots and leaves
– Prunus (cherry): seeds
– California poppy: all parts
– Lupine (annual): seeds, fresh leaves and stems.
Mostly, though, native plants make great additions to the garden. They tend to be well behaved and are rarely invasive. Birds and butterflies rely on them for food, shelter and nesting. And, best of all, they are beautiful.
When I’m designing with native plants, I find the following are fairly safe around deer. They are not perfectly safe at all times of the year, but they are usually avoided.
– California sagebrush (Artemisia)
– Wild ginger (Asarum)
– Dwarf coyote brush (Baccharis)
– ‘Julia Phelps’ ceanothus
– California buckwheat (Eriogonum)
– Douglas iris
– Sticky monkey flower (Mimulus auritanicus)
– Coyote mint (Monardella)
– Fuchsia-flowering gooseberry (Ribes speciosum)
– Salvia
Enjoy your garden. Let the deer browse elsewhere, and be aware of plants that might be toxic to children.
– Jan Nelson, a landscape designer and California certified nursery professional, will answer questions about gardening in the Santa Cruz Mountains. Email her at ja******@ao*.com, or visit www.jannelsonlandscapedesign.com to view past columns and pictures.