Plant a firewise yard
“Fire is more than an ecological process or an environmental problem. It is a relationship.”
— Stephen J. Pyne, author of “Tending Fire: Coping with America’s Wildland Fires,” 2004
A former firefighter, Stephen Pyne is now professor emeritus in the School of Life Sciences at Arizona State University. He’s written more than 30 books in which he focuses on the historical relationship between fires and humans. At the close of his 2015 Ted Talk, Pyne notes, “Our past is a record of how we have used our fire power. Our future will be a record of what we have learned from that experience.”
One of the things humans have learned about fire is that some plants in our gardens and landscapes are better than others at protecting our home from a fire burning nearby.
“Firewise” plants have high moisture content in their plant tissue, low levels of flammable oils or resins, and are low-growing and/or small plants that produce minimal litter. Succulent ground covers are one type of firewise plant recommended for planting close to the house.
Here’s a list of firewise trees and shrubs that was developed by Firewise USA in collaboration with the city of Ashland’s Wildfire Safety Commission. Firewise plants may be safely planted within five feet of a house or other structure. How many firewise plants do you have in your landscape?
Firewise broadleaf evergreen shrubs: Mexican orange (Choisya), boxwood (Buxus sempervirens), rhododendron, camellia (camellia sinensis), distylium, Portuguese laurel (Prunus lusitanica), silverberry (Eleagnus), coffeeberry (Rhamnus), abelia, holly (Ilex), silk tassel (Garrya elliptica) and strawberry tree (arbutus unedo).
Firewise deciduous trees: chaste tree (Vitex agnus-castus), Persian ironwood (Parrotia persica), oak (Quercus) and maple (Acer).
Firewise deciduous shrubs/small trees: azalea (Rhododendron), hydrangea, Japanese maple (Acer palmatum), ninebark (Physocarpus), currant (Ribes), serviceberry (Amelanchier), elderberry (Sambuca), pieris (Pieris japonica), spirea (Spiraea thunbergia), crepe myrtle (Lagerstroemia), daphne, mock orange (Philadelphus), snowberry (Symphoricarpos), cornelian cherry (Cornus mas), tree peony (Paeonia suffruticosa), redbud (Cercis), dogwood (Cornus), hornbeam (Carpinus) and fruit trees.
In contrast, pyrophytic plants are highly flammable because they have high oil or resin content and/or because they produce a lot of litter. The majority of pyrophytic trees are conifers. Some cities, such as Ashland, have adopted fire safety ordinances that prohibit planting pyrophytic plants within 30 feet of any structure, although dwarf or prostrate species of listed pyrophytic trees and shrubs may be safely planted at least five feet from structures. How does your garden and landscape measure up?
Pyrophytic trees: arborvitae (Thuja), cedar (Cedrus), cedar/cypress (Chamaecyparis), cypress (Cupressus), Douglas-fir (Pseudotsuga menziesii), fir (Abies), hemlock (Tsuga), incense cedar (Calocedrus decurrens or Libocedrus decurrens), pine (Pinus), giant sequoia (Sequoiadendron), coast redwood (Sequoia), spruce (Picea) and yew (Taxus).
Pyrophytic shrubs: bitterbrush (Purshia tridentata), broom (Cytisus), ceanothus, (Ceanothus), Himalayan blackberry (Rubus armeniacus), juniper (Juniperus), lavender (Lavandula), manzanita (Arctostaphylos), Oregon grape (Mahonia aquifolium), rosemary (Rosmarinus) and sagebrush (Artemisia tridentata or californica spp.).
Although low-growing ornamental grasses are typically considered to be firewise plants, pampas grass (Cortaderia selloana) is highly flammable, and bamboo (Bambusoideae phyllostachys or fargesia) should be used with caution. Here are other plants that need consistent maintenance of dead leaves and branches for fire safety; they should be planted at least five feet from the house or other structures:
Evergreen shrubs: Japanese plum yew (Cephalotaxus), bottlebrush (Callistemon) and rockrose (Cistus).
Groundcovers: creeping thyme (Thymus), creeping Oregon grape (Mahonia repens), creeping strawberry (Fragaria), kinnickkinnick (Arctostaphylos uva-ursi), phlox (Phlox subulata), sweet woodruff (Galium odoratum), and creeping rosemary (Rosmarinus prostratus).
In addition, Washington State University provides a useful guide for selecting fire-resistant herbaceous perennials and vines that can be grown in the Rogue Valley. Descriptions, pictures and planting instructions are provided for more than 50 kinds of firewise ornamental plants. How many do you have in your garden?
Firewise herbaceous perennials: columbine (Aquilegia), sea thrift (Armeria maritima), milkweed (Asclepias), aster (Aster), basket-of-gold (Aurinia saxatilis), false indigo (Baptisia), pig squeak (Bergenia cordifolia), bellflower (Campanula), Jupiter’s beard (Centranthus ruber), coreopsis, delphinium, dianthus, coneflower (Echinacea), fleabane (Erigeron), hardy geranium, sun rose (Helianthemum nummularium), daylily (Hemerocallis), coral bells (Heuchera), hosta, iris, and red-hot poker (Kniphofia).
Other firewise herbaceous perennials include: shasta daisy (Leucanthemum x superbum), lily (Lilium), blue flax (Linum perenne), lupine (Lupinus), bee balm (Monarda), evening primrose (Oenothera), oriental poppy (Papaver orientale), beardtongue (Penstemon), Jacob’s ladder (Polemonium), black-eyed Susan (Rudbeckia fulgida), salvia, speedwell (Veronica), yucca, and California fuchsia (Zauschneria garrettii).
Firewise vining plants: Kiwi vine (Actinidia kolomikta), chocolate vine (Akebia quinata), crossvine (Bignonia capreolata), trumpet vine (Campsis radicans), clematis, climbing hydrangea (Hydrangea anomala), honeysuckle (Lonicera), trumpet honeysuckle (Lonicera sempervirens), Virginia creeper (Parthenocissus quinquefolia), and purple-leaf grape (Vitis vinifera ‘purpurea’).
The Cooperative Extension Service offers additional advice for planting firewise gardens: Tall perennials may become a fire hazard if they dry out. Keep perennial beds watered and remove dead stalks and foliage throughout the summer. Mulch beds within five feet of the house with compost or inorganic materials.
Be aware that shrubs planted beneath tree canopies or near buildings can become fuel ladders and spread flames. Prune tree limbs 8-15 feet above ground level to help prevent flames from spreading into the tree canopy.
The gardener’s relationship with fire is an ambivalent one. On one hand, the big ball of fire that is the sun allows us to grow plants outdoors, and solar energy provides an efficient way to grow plants indoors. On the other hand, wildfires are increasingly threatening our homes, landscapes, and health, all devastating consequences of humankind’s off-kilter relationship with the natural world.
Fiery political debates will surely continue; in the meantime, gardeners can act constructively by taking another look at their growing spaces from a firewise perspective.
Rhonda Nowak is a Rogue Valley gardener, teacher and writer. Email her at Rnowak39@gmail.com. For more about gardening, check out her podcasts at https://mailtribune.com/podcasts/the-literary-gardener and her website at www.literarygardener.com.\