Bioregional Plant Allies   by Lee Barnes

The following article originally appeared in The Permaculture Activist June 1996, #34 which had the theme of Useful Plants. Copies of this and other issues are available from the Activist (20%discount on 5+). Save 20% on a complete set of back issues. Be sure to visit our Seed Resources and Plant Nurseries pages for access to great plants for your Permaculture landscape.

Lee Barnes (Ph.D. Environmental Horticulture) is an experienced naturalist and dedicated environmental activist, passionately advancing his & others awareness of the Southern Appalachian Mountains Bioregion (Katuah) through bioregional education teachings, book & magazine publications, & Land Stewardship Consulting business.

Dr. Barnes combines his knowledge of natural forest communities, sustainable agriculture & Permaculture training with a bioregional focus & additional “awareness of place” using dowsing/biolocation techniques.

Lee (1993 PDC graduate) has promoted permaculture through numerous presentations & workshops: was a founding member of the Eastern Permaculture Teachers Association; editor & publisher of the Permaculture Connection (1993-95); numerous contributions to the Permaculture Activist; & co-focalizer of the Permaculture Gatherings including webmaster of the Southeastern Permaculture listserv at SoutheasternPermaculture@yahoogroups.com.

He has written extensively about bioregional awareness; old growth forests; useful plants; regional weather & microclimate; & has produced numerous resource lists of edible plants, seasonal phenology, edible perennials, & medicinal plant propagation.

Dr. Barnes spends much of his time consulting with landowners & developers on how to manage their properties in a more “environmentally sensitive” manner. He has extensive knowledge of forest communities; promotes small scale sustainable forest planning; uses maps and aerial photography in “landscape level” design; performs solar analysis for road & house placement; and consults in general landscape design & horticulture problem solving.

Lee is a well-known heirloom & medicinal seed saving advocate & organized numerous seed saving workshops and presentations over the last 15 years. He founded & organized the popular Seed & Plant Exchanges with the Carolina Farm Stewardship Association’s Sustainable Agriculture Conferences & Organic Growers School.

      My understanding of plants has evolved over a lifetime in the horticultural world, but my prime tip for newly budding gardeners and plant explorers is to study carefully the region's natural and introduced plant species and communities. You can check with state natural heritage agencies for plant community descriptions for your area. The book Classification of the Natural Communities of North Carolina is an excellent guide I have used to understand the dynamics and interdependence of plant and animal communities in my part of the world. Learning the local framework of plant/animal/insect associates is very helpful in designing cultivated or wild gardens. When you start to recognize beneficial plant combinations ("guilds") in surrounding natural communities, you can garden using related species in similar combinations.

      Local wild and adapted species should be the first plants to introduce into permaculture gardens, especially since it is easy to collect seeds without disturbing the wild populations. As a general rule collect at most 10% of the seed crop from any single plant population, and spread a few seeds in similar habitats to expand the wild populations. Also model the vertical stacking (or structure) of plant communities in your home landscape to develop more efficient plant combinations.

      Succession is the term used to describe the gradual replacement of one set of plants in a community by another. For example, in this region, when pasture is abandoned from grazing or mowing it evolves into a woodland. The first larger plants to come in are usually blackberries, sumac, persimmon, and pine; and after them, tulip poplar and black locust trees. As these mature, more niches are created for other forest species and, depending on aspect, slope, and elevation of the land, maple/hemlock or oak/hickory forest may come to dominate. By learning to recognize regional plant successions, you can work with natural processes to speed up the evolution of your own systems.

Expanding choices

      How can we determine what non-native plants are appropriate for our gardens beyond those already growing and adapted to the area? Answering this question requires assessing the suitability of the plant to regional climate and ecology, balancing concerns about usefulness, genetic diversity, and risks to existing vegetation, and finally taking heed of regulations aimed at protecting the agricultural economy.

      Five main factors should be considered to determine a plant's adaptability to a particular growing region. Foremost is climate, especially temperature means and extremes, and rainfall quantity and seasonal distribution. Secondly, in most plants dormancy, growth, and flowering respond to the cycles of day-length change (photoperiod). Plant pollination needs will affect successful fruiting and seed production, so pollination insects may need to bee considered. Other important but more easily manipulated factors include soil pH, organic matter, nutrient needs, drainage, and beneficial or obligate soil microflora associations (such as mycorrhizae). Lastly, regional pest and disease pressures may limit plant adaptability and usefulness.

Select plants that will grow

      The ability to produce viable seed is a good indicator of a plant's adaptability to its environment. Plants which reseed themselves or from which we can gather viable seed or propagation material are more useful and more desirable in a permaculture system than those which will grow but not reproduce. The major factors affecting plant distribution, growth, and seed production are the seed dispersal vector(s), length of the frost-free growing season, average and extreme temperatures (both high and low), and seasonal moisture availability. Well known ethnobotanist Jim Duke (Economic Plants for Holdridge Life Zones: Climatic Requirements of 1000 species) lists simplified, quick reference climatic information (based primarily on annual precipitation and temperature ranges) which can be used to assess likely plant performance for any particular climate.

      It is obvious that plants need long enough growing seasons to produce viable seeds (yearly or at least, occasionally), but other factors may limit seed production or viability: non-native plants (or native plants in severely disturbed environments such as clearcuts) may lack natural pollinators and thus require hand pollination to set seed. Or they may lack soil organisms upon which they are dependent.

      Many plants can also be propagated asexually by means of tubers, bulbs, rooted cuttings, etc. so seed production is not always a requirement for choosing plants that will grow in your area. However, by saving seeds, one can both maintain genetic diversity (for stability against environmental changes or resistance to pests and diseases), and select for broad genetic combinations which are better adapted to a particular microclimate, soil conditions, and temperatures, or pest pressures. Suzanne Ashworth's Seed to Seed: Seed Saving Techniques for the Vegetable Gardener*, is highly recommended for many common and uncommon garden plants. My favorite books for woody plant seed and cutting propagation are Dirr and Heuser's The Reference Manual of Woody Plant Propagation, and the USDA's Seeds of Woody Plants in the United States.

      Temperate plants have evolved under environmental pressures to undergo dormant periods (such as winter and seasonal droughts). Probably the most common factor affecting perennial plant distribution in the U.S. and Canada is winter hardiness. Plants offered in the commercial trade are often rated by the minimum temperatures they can survive when dormant. Areas with the same average minimum temperatures have been organized and mapped into a series of "plant hardiness zones" by the Arnold Arboretum at Harvard University, based on temperature differences of 10°F., ranging from Zone 10 (southern Florida, minimums of 30° to 40°F.) to Zone 1 (northern Canada, lows below -50°F.). The hardiness zones have been further divided by the US Department of Agriculture (USDA) into 5°F. differences, resulting in new maps with split zones (eg. Zone 6a, -5° to 0°F.; Zone 6b, 0° to 5° F.)

      Elevation influences the average low temperatures and temperature extremes in an area. A useful rule for elevation influence on minimum temperature is that air temperatures average about 3.5°F. cooler for each 1,000-foot increase in elevation. Choose plants that are adapted to one zone colder for each 1000 feet increase in elevation.

Indicator Plants

      Many common landscape plants can help us determine local hardiness zones. For example, plants hardy to zone 7 include mimosa, Laurustinus viburnum, kurume azalea, English holly, and Atlas cedar: they are not commonly found in Zone 6, except in protected areas.

      Common indicator plants for different zones
      (number = frost free months / yr):

• Zone10 - bougainvillea, rubber plants
• Zone 9 - asparagus fern, fuchsia, Schinus pepper tree
• Zone 8 - Japanese pittosporum, cherry-laurel
• Zone 7 - bigleaf maple, atlas cedar
• Zone 6 - Japanese maple, English ivy, American holly
• Zone 5 - flowering dogwood, common privet
• Zone 4 - sugar maple, Virginia creeper
• Zone 3 - Japanese barberry, Russian olive
• Zone 2 - paper birch, eastern larch, silverberry
• Zone 1 - quaking aspen, dwarf birch.

      These plants indicate expected low temperature extremes. Of course, simple devices such as plastic tunnels or crop covers (Reemay, etc.) greatly extend the range of plants which can be grown, especially in areas where early frosts are followed by weeks of good growing conditions. Currently, a Plant Heat Tolerance Zone Map is being developed to allow more accurate estimates of plant performance in extreme heat.

Chilling Hours

      While plants from temperate climates are capable of surviving a wide range of extreme low temperatures, they also respond to the duration and extremes of cold. Temperate zone plants have evolved biological techniques to measure the average length of winter, actually requiring a critical amount of "chilling" (usually recorded as number of chilling hours below 40°F) to overcome internal time clocks of dormancy. For example, many woody plant species require a minimum number of chilling hours before they will begin to grow in spring. Plants native to New England will require more chilling hours (perhaps 3,000-4,000) to overcome dormancy than will individuals of the same species found at the southern end of their natural range (where they may, for example, require only 500 chilling hours). A similar timeclock is contained in seeds of most temperate perennials, which will need exposure to certain lengths of cold periods, depending on their genetic programing at their original sources. Thus it is best to obtain seeds from perennial plants grown at your general latitude and with similar climate and average number of chilling hours.

Other Factors

      Temperate zone plants also measure day length (termed "photoperiod"), and are affected by a phenomenon called "provenience" where seasonal changes in day length trigger the cycles of growth and dormancy. It is best to select seeds from plants found naturally within 1° of latitude, or about 60 miles north or south of where you plan to establish them. Differences of elevation can also affect plant growth, so plant seeds should be collected from similar elevations for best seasonal hardiness. Other environmental pressures such as high local or seasonal humidity can affect the success of a particular plant which may be affected by foliar fungal diseases, e.g., many rose family plants and tomatoes are difficult to grow organically in the humid mountains of Western NC.

Diversity and Balance

      There are many opinions about the introduction of non-native plants into a new region, the debate raging about the risks of potential rampancy and the possible introduction of pests (fungi, insects, viruses, etc.). I (and others) argue that plants have co-evolved with humans, have migrated with them for tens of thousands of years, and have been increasingly widely distributed in modern times from their original centers of diversity. I believe that any plant which can complete its life cycle (from seed-to-seed) during my area's average growing season (between last and first killing frosts) should be considered as part of a genetically diverse guild of useful plants. While remaining watchful for overly aggressive or invasive species, or plants with known internal pests, we should nevertheless choose food and useful plants from a wide diversity of habitats and gene pools, so that our food supply is not overly dependent on just a few species.

      Less than 20 food plants now provide the bulk of carbohydrates and proteins consumed by modern societies. The dangers of our narrow food base and diminishing genetic diversity are widely reported. Bioregional wisdom suggests that food, fiber, and fuel should become more regionally produced and marketed, based on the local growing season and the available solar, carbon, and nutrient budgets. Sustainable agriculture requires shifting from the high-input monoculture of annuals to low-input culture of mostly perennial species, including native foods, and edible and medicinal "weeds." Producing foods for consumption locally and "in season" (with some cost-efficient season extension techniques) results in the freshest food and the highest levels of nutrition from our gardens. In addition, appropriate low-tech food preservation and value-added processing can greatly increase the bounty and diversity of our diets, and sometimes the nutrition value as well (as with some fermented foods).

Prohibitions

      Be aware that inter-regional trade of some plant species may be restricted by government regulation. In general, seeds are more easily sent across national borders than are plants, which may be required to be grown in soil-less media to prevent the spread of of soil insects and pathogens or held in quarantine for evaluation and testing. Some seeds are known to contain pathogens (usually viruses and fungi) and their distribution may be restricted. Each country and state may have regulations for "noxious" weeds, usually based on potential economic threat. For example, in North Carolina officially noxious weeds include the potentially useful water plants elodea, salvinia, swamp stonecrop, water-chestnut, watermilfoil, and waterprimrose. One should check with local agriculture agencies (Cooperative Extension Service, state Agriculture Departments) for lists of restricted species.

Swap seeds

      Perhaps the easiest way to discover and obtain new plants is through local and international seed exchanges, and especially from regional plant enthusiasts. The Permaculture Seed and Plant Exchange lists nearly 500 different species of useful plants, along with cultural information, and seed or plant sources. Joe Hollis, editor of the PcSPE, also lists over 700 species of useful plants which he grows or collects from his surrounding mountain county (he lives in the Southern Appalachian "breadbasket" of plant diversity). Hollis has another "wants" list of over 1,000 species of interest.

      The Southern Grasslands Seed and Plant Exchange in Southeastern Texas (cited in PCA 31:44) is a good example of a regional exchange. Other useful plant and seed exchanges include Seed Saver's Exchange, Flower and Herb Exchange, and other exchanges sponsored through leading plant societies such as North American Fruit Explorers, Northern Nut Growers Assn., and California Rare Fruit Growers).

Plant Talk

      To share knowledge of plants, it is most helpful to learn botanical vocabulary and Latin plant names. Most botany texts and plant identification keys contain glossaries which define important botanical words. About 100 different terms are commonly used in plant keys. The use of Latin plant names (binomial nomenclature) is critical to positive plant identification, since most cultivated and many wild plants have several common or regional names. Learning botanical Latin is easier than you might think. About 10% of commonly used English words already come from Latin, so you will recognize many plant names from related words you already know.

      Latin binomials (especially species names) often give clues to plant characteristics or adaptability. For instance, the Latin name may indicate blooming time or season of the year (vernalis = spring); emphasis, degree, or kind (semper = ever, always, escans = resembling); size and shape (gracilis = slender, grandi = large, giganteus = huge); regions or habitats (agrarius = of fields, australis = southern, occidentalis = western, sylvestris = of woods); plant character, form, and habit (alatus = winged, floridus = flowering, muralis = of or for walls, radicans = rooting); or plant parts, color, or flower numbers and quantity. Bailey's How Plants Get Their Names is a useful and inexpensive guide to Latin terms and pronunciation.

      Much information about suggested plant species is available from local offices of the Soil Conservation Service, Cooperative Extension Service, public agricultural universities, and state forestry departments. Check your local phone book or write to state offices for publication lists.

Other Good Books on Plants

      My favorite widely available book references to useful plants include Mike Dirr's Manual of Woody Landscape Plants, Sunset's Western Garden Book, and Reader's Digest Illustrated Guide to Gardening. For more details on potentially useful plants I always check Stephen Facciola's Cornucopia, Sturtevant's Edible Plants of the World (edited by Hendrick), Fernald and others', Edible Wild Plants of Eastern North America, and the excellent database, Useful Temperate Plants * (Crawford). My favorite is Cornucopia, which lists over 3000 species of edible plants, with extensive cross-referencing by common and botanical names, and also has an extensive Index of Usage and Edible Parts from "adjuvants to yeast hosts."

Several magazines provide information on useful plants - one of my favorites is HortIdeas, an easy-to-read digest of dozens of magazines and botanical journals, giving overviews of current plant information and new findings.

Some Useful Plants
(see our list of Plant Nurseries at this site)

      What follows here is a short sample of plants for permaculture gardens arranged by some general uses. Most of these plants are easily grown from seed. The ultimate way to determine useful plants for a particular area is by growing several new species and different varieties each year. Remember that success is affected by seed source (so try several sources), environmental pressures (don't give up if the plant does not do well one year, a different source or different season may result in success), and by the growers' willingness to observe and learn from each experience. Remember to multiply useful plants and to distribute superior varieties widely. Play nice, share, and we will all eat better.

Under-used, Perennial, and Self-seeding Plants

      Edible Ornamentals- bamboo, quince (Cydonia oblonga), globe artichoke (Cynara scolymus), dandelion (Taraxacum officinale). Ornamental Leaf Vegetables - Egyptian onions (Allium proliferum), amaranth (Chenopodium spp.), ruby/rainbow chard (Beta vulgaris), nasturtiums (Tropaeolum majus), ornamental cabbage/kale (Brassica spp.)

      Edible Flowers- chives (Allium schoenoprasum), hollyhocks (Alcea rosea), ox-eye daisy (Leucanthemum vulgare), borage (Borago officinalis), edible chrysanthemum (C. morifolium), passionflower (Passiflora spp), pansies, violets (both Viola spp.)

      Perennial Salad Greens - salad burnet (Sanguisorba minor), sorrel (Rumex acetosa), dandelion, viola spp., chickweed (Stellaria media) [self-seeding]

      Beneficial Insects Plants - borage, butterfly bush (Buddleia), buckwheat (Fagopyrum esculentum), lemon balm (Melissa officinalis), yarrow(Achillea millefolium), fennel (Foeniculum vulgare), and other umbels.

      Living Mulches- yarrow, thrift (Phlox subulata), Ajuga reptans, wild strawberry (Fragaria spp.), stonecrop (Sedum spp.), periwinkle(Vinca minor), white clover (Trifolium repens).

      Useful Climbers - kiwi (Actinidia spp.), hops (Humulus lupulus), passionfruit (Passiflora spp.), grapes (Vitis spp.) Nitrogen-fixers/Legumes - crownvetch (Coronilla sp.), scotch broom (Cytisis scoparius), honey locust (Gleditsia triacanthos), black locust (Robinia pseudoacacia), vetches (Vicia spp.,), peanut (Arachis hypogaea), Dolichos lab lab, beans.

      Water Plants - sweet flag (Acorus calamus), marsh marigolds (Caltha palustris), water chestnuts (Trapa natans), water cress (Nasturtium officinale), duckweed (Lemna sp.), watermint (Mentha aquatica), wild rice (Zizania aquatica).

      Unusual Roots - garlic mustard (Alliaria petiolata), burdock (Arctium minus), horseradish (Armoracia rusticana), Jerusalem artichoke (Helianthus tuberosus), oxalis, Chinese artichoke (Stachys sieboldii), dandelion, tuberous nasturtium (Tropaeolum tuberosum).

      Chicken Fodder - bamboo spp., shepherd's purse (Capsella bursa-pastoris), mulberry (Morus spp.), comfrey (Symphytum officinale), Good King Henry (Chenopodium bonus-henricus), elderberry (Sambucus nigra).

      Fruiting Shrubs/Trees - serviceberry (Amelanchier canadensis), quince, Russian olive (Elaeagnus angustifolia), medlar (Mespilus germanica), plum (Prunus spp.), raspberry, blackberry,wineberry, loganberry (all Rubus spp.), elderberry.

      Bee Foods/Honey Plants - alder (Alnus spp.), black locust, sourwood (Oxydendron arboreum), buckwheat, clovers, basswood (Tilia americana).

      Wild Foods - ramps (Allium tricoccum), pawpaw (Asimina triloba), maypop (Passiflora incarnata), prickly-pear (Opuntia spp.), husk tomatoes (Physallis ixocarpa), huckleberry (Vaccinium arboreum), persimmon (Diospyros virginiana).

Recommended Books

Crawford, Martin. Useful Plants for Temperate Climates. 1992ff. Agroforestry Research Trust: Vols. 1 & 1a, Trees; Vols. 2 & 2a, Shrubs; Vol. 3, Perennials; Vol. 4, Annuals & Biennials; Vol. 5, Algae, Fungi, and Lichens. Additional unnumbered volumes on bamboo, ground cover plants, climbers, and timber trees for temperate climates. -- most extensive info source on temperate plants.

Dirr, Michael and Heuser, Chas. Jr. The Reference Manual of Woody Plant Propagation: From seed to tissue culture. 1987. Varsity Press, Univ. of GA. 239 pp. -- lists propagation details for over 1100 species.

Litwin, Anya. Plant Species Index for the Pacific Northwest and General Reference. 1990. Ecology Action. -- inexpensive, easy to use guide.

Schopmeyer, C. S. Seeds of Woody Plants in the United States. 1974. Forest Service, USDA Agriculture Handbook No. 450. USDA. 883 pp.-- The reference for seed handling and germination of 188 genera of woody plants native or naturalized in the U.S. (mostly temperate spp.) Very detailed with additional references.

Seed Saving Organizations/
Seed and Plant Exchanges
(see our list of seed resources at this site)

Seed Saver's Exchange, P.O. Box 70, Decorah, IA 52101 -- nonprofit, grassroots organization dedicated to preserving genetic diversity in fruits and vegetables.

Flower and Herb Exchange, 3076 North Winn Rd., Decorah, IA 52101. -- "sister" organization to SSE focusing on ornamentals and herbs. 1994 listing included nearly 2,100 listings.

Permaculture Seed and Plant Exchange, 3020 Whiteoak Creek Rd., Burnsville, NC 28714 USA - newly developed seed and plant exchange by Joe Hollis and friends. Unique collection of sources and cultural information on over 470 species of mostly temperate perennials and self-seeding annuals, medicinals, etc. Single best collection of sources for useful permaculture plants in temperate America. ($7/year).

Southern Grasslands Seed & Plant Exchange, P.O. Box 603, Navasota, TX 77868. ($5/year membership). - Organizer Hans Hansen defines this as serving that portion of the Great Prairie lying south of the Red River, but welcomes exchanges with other regions. SGSPE issues a directory twice a year plus one newsletter. Members list offerings at no charge. Trades are arranged between individuals.

Seed Saving References

Ashworth, Suzanne. Seed to Seed: Seed Saving Techniques for the Vegetable Gardener. 1991.Seed Savers Publ. 222 pp. - excellent, easy-to-use guide to saving heirloom & open-pollinated varieties with techniques to maintain genetic purity, seed storage, etc.

Miller, Douglas. Vegetable and Herb Seed Growing for the Gardener and Small Farmer. 1977. Seeds Blüm. Reprint 1984. 46 pp. $4.75 ppd. -- easy to follow guide to seed saving.

Deppe, Carol. Breed Your Own Vegetable Varieties: Popbeans, purple peas, and other innovations from the backyard garden. 1993. Little, Brown & Co. Publishers. 303 pgs. -- layman's guide to breeding techniques and strategies. More technical than other books listed above.

Bubel, Nancy. The New Seed-Starters Handbook. 1988. Rodale Press, 385 pp. -- general text describing seed-starting techniques for a variety of vegetables, fruits, trees, grains, herbs, etc. Includes 65-page section on seed-saving.

M.T. Mirov and Charles Kraebel. "Collecting". USDA CCC Forestry Publication No. 5. 1939. (available through Inter Library loan) -- excellent introduction to seed-saving of native plant spp.

*Facciola, Stephen. 1990. Cornucopia: A Source Book of Edible Plants. Kampong Publ. 677 pp. -- incredible botanically arranged guide to edible plants, the best of its kind! Describes over 3000 edible plants and their commercial sources. Extensive review of cultivars of over 100 major food plants. Lists 52 pages of domestic, foreign and commercial sources for these plants. Extensive bibliography and appendices.

Whealy, Kent. Garden Seed Inventory: An Inventory of Seed Catalogs Listing All Non-Hybrid Vegetable Seeds Still Available in the United States and Canada. 2nd Ed. 1988. Seed Savers Publ. 422 pp. -- describes over 5000 non-hybrid varieties, including info on maturity dates, disease resistance, etc., as well as commercial resources

Useful Plant Magazines

HortIdeas. 460 Black Lick Rd., Gravel Switch, KY 40328. Subscriptions $15/yr.