Gardening and farming are both a matter of co-existing with wildlife, from microscopic life in the soil to the large hooved animals in our area. Those of us who revere IPM (Integrated Pest Management) don’t bother to control destructive insects until the damage becomes too severe to tolerate. Some of us use beneficial insects to control the bad guys. The longer one gardens, the more one appreciates nature.
Some of us raise ducks and chickens, moving their cages (”chicken tractors”) about in the garden to control slugs and insects, some of us release lady beetles to let them control aphids, and still others patrol garden plants with wasps, watching them snag tiny larvae with which to provision their egg cases. When their eggs hatch, there’s a handy larva to be consumed.
To avoid poisoning and killing deer, elk, moose and pronghorns, Idaho Fish and Game botanist Lynn Kintner suggests we plant Idaho native shrubs instead of yews and other evergreen shrubs that are deadly to those ungulates (hooved animals). Evergreen native shrubs that are safely ingested by those that browse on twigs and needles include Oregon grape-holly (Berberis aquifolium) and Oregon boxleaf (Pachystima myrsinites), both tolerant of shade. A large fern, Western sword-fern, is also evergreen and shade tolerant, not toxic to wildlife.
Deciduous shrubs that tolerate shade and are not toxic include some natives such as Woods Rose (Rosa woodsia), Thimbleberry (Rubus parviflorus), Oceanspray (Holodiscus discolor), Mallow ninebark (Physocarpus malvaceus, golden currant (Ribes aureum), red flowering currant (Ribes sanguineum), common snowberry (Symphoricarpus albus), and the ornamental red and yellow-twigged dogwood.
Other woody plants safe for wildlife include arborvitae, evergreen huckleberry, false cypress, highbush cranberry, and syringa (Philadelphus lewisii), the latter our state flower. Euonymus species may be tolerable for wildlife, although E. atropurpureus is toxic to horses.
I know deer browse on rose bushes with no apparent ill effects, and I suspect there are other shrubs such as Mahonia that are not toxic. Birds eat Mahonia berries and eliminate seeds somewhere else, so Mahonia plants pop up where you least expect them. A spade, angled at 45 degrees, thrust into earth next to unwanted volunteers cuts them off below soil line, and they don’t come back. Some regard Mahonia as invasive, but it’s so easily controlled, I disagree with that assessment.
Some popular ornamentals, such as azaleas, rhododendrons, mountain laurel and photinia species are poisonous to deer, elk and the other hooved animals. I’ve not heard of their culpability in wildlife deaths in this area this year, however. Their poisonous effect is not as immediate as that of yews, and they may not be attractive to hungry wildlife.
All four species of yew in the Baccata genus -- Irish, European, Himalayan, and European yew -- have virulently toxic twigs, needles and berries. Veterinarians examined four of the 50 dead pronghorns that recently died near Payette and found yew twigs and needles in their stomachs. Since all 50 carcasses were found fairly close together, it was a logical assumption that all had been similarly poisoned.
The photo of that killing field is sufficient for most of us to remove yews from our landscapes. If you’re really attached to a yew, please wrap it in burlap until spring.
Send garden questions to firstname.lastname@example.org or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.