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Guilds for Bookworms
The most successful guilds are those designed after prolonged observation of a natural community. These guilds have the best chance of clicking into the
dynamic relationships that wild plant communities embody. But gaining enough knowledge to design on the basis of prolonged observation takes special
dedication. For ecological gardeners who haven’t the time or inclination to spend hours—or years—with a natural community, I present a more academic,
armchair method of guild design. Remember, though, that nothing substitutes for observation, and even a brief field trip to a plant community can yield
critical insights that books can’t give.
The armchair method begins with a search for lists of the major plant communities native to your area. This information resides in ecology and plant
field books, forest service websites, and journal articles in university libraries or online databases. This literature is abundant and dense and may require
some digging to extract the relevant nuggets. In my own neck of the woods, I would begin by searching under “Plant Communities, Oregon” in a university
library catalog or database index. In your search, plug in your own state’s name. When the lengthy list of references comes up, watch for titles such as
“Plant Associations of (your state),” or “Vegetation of (your county).” If you know the dominant native tree in your region, you can narrow down the search
by seeking research on that species. I have a handy paper called “The Quercus garryana Forests of the Willamette Valley,” which describes the Oregon
white oak forests that rule the dry hillsides of my region.
Using Natural Plant Communities to Guide Guild Design
Based on the work of Tim Murphy and other guild designers, we can develop some guidelines for creating guilds from local plant communities. Here
are some questions to ask that will help select plants for useful guilds:
1. What is the dominant species of the community? Is it useful for humans, via nuts, fruit, particular beauty, animal feed, or other benefit? Is a related
plant even more useful?
2. Which plants are offering food to wildlife? What wildlife uses them? Are these animals desirable in the yard?
3. Are any plants capable of providing food for humans? Do any plants in the community have domesticated relatives that can provide fruit, berries,
tubers, greens, herbs, or other products for people?
4. Which species are common to more than one community, as opposed to those unique to only one? These may be possible buffer or transition
plants to connect a guild to the rest of the yard.
5. Does any species show exceptional insect damage or have large numbers of harmful insects living on it? This might not be a desirable variety.
6. What species generates most of the leaf litter? Would it make a good mulch plant?
7. How well, and by what mechanisms, does the community withstand drought or flood? Some desert plants shed their leaves in extreme dryness, a
useful quality but not an attractive habit for a major planting.
8. Do any plants have bare ground or stunted vegetation near them? This may simply be due to deep shade, but if sunlight reaches the soil near this
plant, the species might be an allelopath and worthy of caution.
9. Are any plant families heavily represented in the community? If so, domesticated relatives might be successfully substituted.
10. Does the community contain any known nitrogen fixers or other nutrient accumulators? These may be critical members and necessary for a
related guild.
The answers to these questions will generate a list of species that can form the backbone of a potential guild.
If this research process seems daunting, some legwork can be circumvented by calling the nearest college botany department or USDA Forest Service
office and asking where to find descriptions of the plant communities of your area. Someone in the department will know the name of the best books or
journal articles for you and may even be willing to give an impromptu telephone lecture on local plant communities.
Here’s how I built an armchair guild for my bioregion when we lived in southern Oregon. On my bookshelf sits the bible of plant communities for my
locale, Vegetation of Oregon and Washington, by Jerry Franklin and C. T. Dyrness. Though it’s more than twenty-five years old, the species lists are still
valid. Thumbing through this book, I see that plant communities are listed not only by region but also, bless the authors’ hearts, by climate and soil
preference. Our former home in Oakland hugs the brow of a south-facing hillside that bakes to withering dryness in summer; thus, for that microclimate, I
needed to find a native plant community that tolerates hot, dry, clayey slopes. Franklin and Dyrness suggest that Oregon white oak, Quercus garryana, will
thrive in those conditions. This was no surprise, as both my woods rambles and the paper cited above taught me that Oregon white oak loves it there. It
was reassuring, though, that the professors and I agreed.
White oak communities, Franklin and Dyrness reveal, come in several varieties, each named for the most prevalent understory shrub. These
communities are called white oak/hazelnut, white oak/ serviceberry, and—gulp—white oak/poison oak, which unfortunately is all too common down there.
Each community contains a dozen or more associated plants that are listed in the text or in a table.
Next, I scanned these lists for species that are useful in themselves or have relatives that yield food, habitat, or other gifts. My goal was to use the
original community members or related substitutes to create a guild with a structure similar to the native community but one that provides products for
humans in addition to its many natural functions. The white oak/hazelnut community has excellent potential since it includes several nuts, fruits, berries,
and herbs. The members of the community are shown in Table 9-1.
With a little exploration and fine-tuning, the white oak/hazelnut community can be transformed into a very useful guild. Let’s walk through the species list.
Oregon white oak has subtle virtues. It’s a lovely shade tree, and mature specimens bear abundant acorns cherished by wildlife. Oaks often swarm with
birds probing the bark for insects. The acorns were a major protein source for Native Americans, roasted whole or ground into flour. White oak acorns
contain less bitter tannic acid than others and thus don’t require the complex leaching process that renders many acorns palatable. They also make
excellent animal feed. Will suburban gardeners eat acorns? I confess I’ve only experimented with them, and I’d wager their acceptability as modern food
is limited. The tree also takes a decade or more to bear acorns, so they’re not an ideal human food plant. Oak wood is valuable timber, but unless you’ve
got some acreage, cutting down a major yard tree is potentially disastrous, and it certainly disrupts the guild.
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Thus, white oak’s food value for humans is limited, and its timber value in a suburban yard is doubtful. Is Oregon white oak useful enough to hold down a
guild? Here is my reasoning: If I demanded that every guild’s central tree provide me with copious food, I might substitute an oak relative, the chestnut,
and hope that it wove well into this guild. I might even rove far afield and experiment with a fruit tree or other species, especially if I could take advantage
of a mature specimen already present. But with all of oak’s gentle benefits, especially for wildlife, plus its status as one of our most charismatic trees, I’m
inclined to overlook its slight food value for humans. For me, the oak is a fine focal tree for a guild. I grow other trees for fruit and nuts.
The second major component of this oak community is the California hazel. No major substitution is needed here, just a little domestication. Hazelnut is
a very useful plant. The hazelnut genus has been bred into a suite of heavy nut-producers such as European and Turkish filberts, filazels, hazelberts, and
the tree hazel or trazel. Not only are the shrubs attractive, but birds love hazelnuts, too, and you’ll probably share your harvest with them, like it or not. With
white oak and a domesticated hazelnut, we’re on our way to a useful guild.
Often the Oregon white oak community harbors another tree species, Pacific madrone. Here we have several choices. The madrone is an outstanding
tree, luring immense flocks of birds to munch the prolific flowers and berries. Its smooth red bark is gorgeous, flaking off each summer to bring in birds in
search of insects under the cracking fragments. Should the tree come down, the firewood is denser than walnut and burns hot and long. However, I’m
hesitant to place both oak and madrone—large trees with limited food value—into a guild, especially in a small yard. Unless you live on a half-acre or
more, you might declare that this guild just ain’t big enough for the both of them. But there is hope. The madrone’s genus, Arbutus, also contains several
smaller species, and my suggestion for using this genus is to plant madrone’s close relative, the strawberry tree, Arbutus unedo, which bears creamy and
sweet, somewhat seedy fruit. Strawberry tree in its full-sized version grows twenty feet tall, but there are bush and dwarf cultivars that will nestle under an
oak easily.
The understory of the white oak community holds two small trees, mazzard cherry and black hawthorn. Coopting these species into our guild is easy
because each is useful in wild or domesticated form. Mazzard cherries are relished by birds, though humans will find the fruit good only for an occasional
sour mouthful or for pies. Promisingly, mazzard is also a commonly used cherry rootstock, available at nurseries grafted onto sweet or pie cherry
scionwood. These grafted cherries could be introduced into our guild. The second small tree, black hawthorn, is not only beautiful but a superb wildlife
plant as well, with berries that carry many birds through the winter. It’s a close relative of the pear and can be easily grafted to become a pear-bearing
variety. Pruning will keep these two already small trees at manageable height. With cherry and hawthorn, we now have an understory that generates food
for wildlife and humans.
The white oak community, as the list shows, is loaded with berries. Serviceberry (also called juneberry or saskatoonberry) has been domesticated into
varieties that yield excellent fruit, so let’s plug in some of these. Thimbleberries are a treat known to all Northwest hikers; they rival raspberries for flavor.
Two species of blackberry twine among this community; but, for the sake of your skin’s integrity, I’d substitute the thornless variety. Snowberry doesn’t
taste very good to humans since the fruits contain soapy saponins, but birds savor the plant. Snowberry is related to honeysuckle, which suggests a
possible ornamental and wildlife-attracting substitute. And, finally, wild strawberries are an obvious choice for a tasty ground cover.
A Los Osos, California, hillside that was once covered in iceplant is transformed into a terraced food-forest a few steps away from the front door. Inspired
by the Asian design of the surrounding buildings, the garden includes Indian Banana surrounded by a living perennial mulch and groundcover of
Vietnamese cilantro (Polygonum odoratum), Japanese sweet Potato (Ipomoea batatas), and nasturtiums. Nearby broomcorn (Sorghum sp.) balances
the height of the banana. Various thymes knit the stepping stone pathway together with aromatic herbs. DESIGN AND PHOTO BY LARRY SANTOYO.
Table 9-1. Members of the White Oak/Hazelnut Community
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Why on earth, you ask, did I include poison oak? This rash-producing shrub and its relative, poison ivy, remind me of the “Police Line—Do Not Cross”
ribbons that cordon off crime scenes. The plants move into abused, chewed-up land and cloak it with a protective, human-deterring barrier. Poison oak
seems to say, “You humans messed this up; now stay away while it heals.” Gardeners obviously won’t want to plant poison oak, but a harmless relative,
lemonade berry (Rhus integrifolia), bears flowers that can be steeped in boiling water to make a tangy drink. The flowers secrete nectar for insects, and
birds enjoy the berries. A Southwest native, lemonade berry is hardy enough (USDA Zone 7) to survive in my Oregon yard. One drawback: Lemonade
berry even looks like poison oak, so a gardener might accidentally grub it out during a robotic weeding frenzy.
Sweetbriar rose illustrates the line we’re trying to tread between wild and domestic. You could use the native species or select a different variety, such
as Rosa rugosa, that bears large, edible hips for both you and animals. But I recommend that you shun the heavily domesticated hybrid roses; their
pollenless blossoms lack wildlife value, and they demand incessant care. For guild plants in general, choose the less domesticated varieties. Humans,
adaptable generalists that we are, can learn to savor new, wilder tastes. Animals are often less flexible and have nutritional or taste requirements that are
missing from highly bred cultivars.
The remaining shrub, oceanspray, is also called ironwood because its stems are steel hard and slow to burn. Native people fashioned arrow shafts,
digging sticks, and eating utensils from the wood, which suggests potential carving projects to me. Also, the shrubs swarm with birds, which eat the seeds
and hide among the dense twigs.
Three small plants finish our list. Sweet cicely (Osmorhiza chilensis, not to be confused with an eastern plant called sweet cicely, Myrrhis odorata,
which also has edible leaves, seeds, and young roots) has an anise-flavored root used for seasoning, and the flowers attract butterflies and other insects.
Yerba buena is a trailing, aromatic herb with leaves that produce a mild sedative effect when steeped as a tea. American vetch fixes nitrogen, but I might
swap it for the more readily available common vetch.
Our white oak guild now contains plants for food, birds and mammals, insects, herbal medicine, and nitrogen fixation, which covers most of the
necessary roles of any guild. The only obvious omission from the list is a heavy-duty mulch plant such as comfrey or artichoke. I’d recommend a few mulch
plants initially to jump-start biomass production and then eliminate them later when the guild fills in. The guild will accumulate plenty of leaf litter once it’s
mature. Also, my intuition tells me a few more insectary plants (herbs such as dill or fennel or suitable natives) and more nitrogen fixers (perhaps beans
and clover or the native, insect-attracting ceanothus) are also in order. The insectary plants will ensure good pollination and fruit set, which is important
because we’ll be harvesting this guild’s products intensively. Also, we’re pulling products out of the ecosystem’s loops; thus we need to replace what
we’ve withdrawn by importing nutrients via nitrogen fixers as well as mulch and nutrient accumulators.
In summary, the armchair method of guild construction begins with a library or Internet search to identify a plant community that suits your region, soil,
and climate. Then, list the component species and gather either these native varieties or domestic cultivars. Try to balance both your own desire for food
and other products with the needs of the wild creatures that will also depend on your guild. If you’re not familiar with the plants you’ve listed, consult native-
plant books, websites, and nursery catalogs to become acquainted with them. If the new guild lacks any of the elements listed in the above section on the
apple-centered guild, fill in the gaps with species listed in this chapter and in the appendix. Also, I strongly urge that you trek out into nature and find a
living example of the native community, if only to get a cursory feel for its patterns and structure. Then plant the guild, stand back, and wait to see what
connections emerge.
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Function-Stacking in Guilds
In the last chapter I described the major functions needed in a fruit-tree guild: nutrient accumulators, barrier plants, insectaries, and so on. That list is really
just a compilation of the basic needs of a fruit tree. We can expand upon this approach by imagining other functions that might be needed or desired in a
guild. Table 9-2 lists some of the possible roles that plants can play, both as supporting actors in the ecological theater and as bearers of many gifts for
humans. The fruit-tree guild was designed by observing what jobs support an apple tree. In our landscapes there are plenty of other functions that need to
be fulfilled to create a healthy ecosystem, and we can also envision activities (such as air cleanup or erosion control) and products that people desire.
Guilds can be designed so that its members fill a variety of roles that are needed by the site or designer, as in the apple-tree guild.
Alternatively, a guild can be created to have one main function. For example, let’s design a guild for attracting birds. We can begin by selecting several
shrubs or small trees known as stellar bird-food and shelter species and that not-so-incidentally have other functions. Examples are:
• Red-osier dogwood (Cornus sericea), for its protected perching sites—while also offering basketry supplies and dye and cordage from the bark.
• Bayberry (Myrica pennsylvanica) for both habitat and food. The berries hang on into winter, which extends the food-bearing season of this guild. The
leaves are a bay-leaf substitute and the berries yield a fragrant wax used in candles.
• Highbush blueberry (Vaccinium corymbosum) for shelter and food, plus sweet berries for us, and a host of mycorrhizal associates for soil-building.
These can form the core of the guild. We’ll want some smaller plants, perennial flowers that bear seeds and attract bugs for birds. Of thousands to
choose from, we could select:
• Maximilian sunflower (Helianthus maximilianii) with its fall seeds and dense, sheltering foliage, as well as shoots we can eat and late-season
blooms.
• Asters of all kinds (Aster spp.) provide seeds and attract tasty insects for birds to munch.
• Purple coneflower (Echinacea purpurea) also offers seeds, as well as having medicinal properties and attracting beneficial insects.
These six form a nucleus that we can build on. We’ve got bird attracting in the bag, extended over a long season. We want to make sure that the basic
needs of this plant community are taken care of, too, so we don’t have to trade our labor for what nature can provide. Obvious holes in this guild include
nutrient accumulation and mulch-making. For the first, how about a lupine, which not only is a nitrogen fixer but in fall offers seedpods enjoyed by
songbirds? The stems are also a choice nest material. For mulch, we could fall back on our old reliable, comfrey, or continue with the bird-luring theme
and choose flame acanthus, a red-flowered variety of bear’s breeches, a perennial with thick, broad leaves. Depending on soil conditions, microclimate,
and other environmental influences, we may want to add other species to round out our guild.
Table 9-2. Guild Plant Functions
Thus we can design a guild to take on a needed role. These function-specific guilds are, as far as we know, not like communities found in nature, so
we’re in new territory here. However, we need not worry much that novel plant combinations won’t work well together. After all, most landscape designs
pay little regard to whether plants are compatible beyond whether the assemblage looks good, and the plants usually survive. As long as the basics such
as soil, light, and water are suitable, the guild members ought to flourish. Only rarely do plants have negative interactions that could cause discord in the
guild. So the downside of guild innovations is slight, while the upside—brilliant synergies, serendipitous benefits, superb habitat—is enormous.
Documents you may be interested
Documents you may be interested
