Strategies for Dry Lands

As we become more familiar with the characteristics of our bioregion – its climate, soil, flora and fauna, we will have experiences that are both exhilarating and frustrating. Just as there is nothing as gratifying as sowing the seeds for a crop in time for a five or six day spring drizzle, there is nothing as disappointing as losing half of your newly planted fruit trees to a summer dry spell. Every storm, drought and freeze serves as a reminder that a designer’s work is not finished until she or he has seen their system withstand the elemental forces of Nature. If we are cunning designers then we can anticipate these forces ahead of time, diffuse them and put them to good use.

Our permaculture institute is located amidst the Cross Timbers bioregion of north central Texas which is a scrub-oak woodland covering steep limestone ridges and hills, narrow ravines and sandy flats. First frost might hit on November 12th and last frost is usually no later than March 21st. Our growing season is over 210 days long with growing opportunity right through the winter. Annual rain fall is between 25 and 40 inches with possible 6 to 18 inch rain events over the course of two days in the fall or spring and with 6 to 8 week dry spells in the summer and winter. The dry spells are long enough and frequent enough that most of our design strategies need to be suited for dry lands even though the annual rainfall seems to indicate otherwise. The Cross Timbers is rated as having a high wind energy potential and parts of northern Texas are ranked second only to Arizona in days of full sunlight. So the strongest elemental forces we face are also potentially the highest yielding.

Texas is not a continuous desert as a lot of western stories and movies might lead you to believe, far from it actually, but our hot and dry summers are indeed infamous and present the greatest design challenges. Human settlements need to be well suited for the extreme heat. Proper orientation, good ventilation and shade are crucial in order to achieve a 60% to 80% rate of energy efficiency and conservation. The straw bale house we built in the fall of 2010 illustrates a few of the measures necessary to achieve such energy efficiency. The house faces almost due north and sits length-wise on an east to west axis. There are glass doors and windows on the south wall for letting in the winter sun and no windows on the west wall for keeping out the setting summer sun. The prevailing south south-westerly wind passes broadside through the entire house, keeping it at about 90 degrees on the hottest summer days and quite cool at night.

Since there were no trees on the site when we began construction creating a shaded micro-climate has been our top design priority. For quick shade we plant Caster beans each spring around the entire west end of the house. Caster beans can grow to be 12 feet tall in one growing season so by mid summer they are quite effective in shading the west end of the house. Another fast growing annual is the Scarlet runner bean which will cover a trellis system over the south-west and west walls very well by mid to late summer. Perennial vines such as the Champanel grape and Hardy kiwi have also been planted to permanently cover the trellis and part of the roof. Finally, we have planted Cottonwoods and Water oaks to shade the entire house and roof in 10 to 20 years. We hope that with sufficient tree cover and shade the air will be cool enough around our straw bale house to eliminate the need for fans all together even during the hottest summer days.

Unfortunately, in the Cross Timbers many land owners are at odds with the trees covering their property. Most of the trees are methodically cleared in order to create pasture for cattle and goat production leaving only a sprinkling of solitary oaks amidst a biological desert of introduced annual short grasses. A few shade trees are also left standing around the land owner’s residence. The result is a picturesque yet bleak pasture that no longer has the stability of a natural ecosystem. In the mid 1970’s the remaining Red oak and Live oak population became susceptible to a lethal fungal blight, Ceratocystis fagacearum, referred to as oak wilt. Consequently, many homes have lost and will continue to lose their only shade trees as well as the remaining oak trees in their pastures. For over 25 years oak wilt has wrought ecological and economical havoc on par with that of the Dutch elm disease and the pine bark beetle. The Texas Forest Service combats the blight as if it were an army at war. Newly infected Red oaks are cut down and destroyed, expensive fungicides are pumped into the ground and bull dozers have ripped millions of feet of trenches around the surviving Live oaks to prevent the fungus from spreading from root to root. The damage is estimated in millions of dollars and hundreds of thousands of dollars are being spent on a means of control that are not even proven to be effective, and yet the real problem, human management of woodlands, has not been addressed.

We strongly believe that the oak wilt is the result of over clearing woodlands and reducing the diversity and richness of the ecosystem. Left alone in a field of short grasses the oaks are more susceptible to drought and pestilence than they would be if they were surrounded by the flora and fauna they co-evolved with. Our recommendation is that if a land owner is compelled to clear their land for grazing that they leave all of the “trash” trees standing within the drip lines of the oaks rather than clearing right up to the trunk of the oak which is the common practice. These “trash” trees – the Juniper, Hackberry, Cottonwood, Mesquite, Elm, Ash and others will shade the ground under the oaks, add their leaf and branch litter to the soil, and offer some protection to the next generation of oak trees sprouting underneath the parent tree. Local extension agents refer to such clusters of trees as motts. Strategic lines of sight can be cleared between motts to give a land owner a sense of openness allowing them to see the road, a livestock watering tank or a favorite afternoon resting place of their herd. Unless we make an effort to not only protect but restore the biological richness of the Cross Timbers oak wilt is probably only the first of many severe blights yet to come.

Fortunately, for a permaculture designer there are some advantages to buying and restoring degraded pasture land. One is that many of the invasive “trash” trees on old pastures (which actually lower the real-estate value) are quite useful. Take the Juniper for instance, its rot resistant wood is excellent for posts and beams, its berries can be used as an anti-biotic or anti-viral in small doses and the oil from its berries was used by women for causing abortions, but this could be fatal to the mother. Then there is the Mesquite which fixes nitrogen, offers a dappled shade perfect for growing crops under and produces a hard wood excellent for grilling and smoking meats. Another common pasture invader is the Sumac tree (Rhus glabra, but not Poison Sumac, another Rhus species) whose bark is an astringent and used for treating sore throats, diarrhea, vaginal bleeding or prolapse. Sumac berries also make nice tea. The other advantage to restoring degraded pasture is that it is easier and less disruptive to install swales and ponds since the land has already largely been cleared. Putting in earthworks is the first step we should take anyway when building a settlement since it is easier to dig a swale and then plant in and around it, rather than vise-versa.

Swales and shade trees are essential in this region for establishing low maintenance food forests and perennial food plots. Without these components water demands would be unaffordably high. In the bottom of our swales we can grow Dew berry bushes (Rubus spp., its leaves and fruits are used to stop diarrhea), Black berry bushes and a guild of Asparagus and Comfrey. Soon we will be experimenting in one of our swales with a variety of Blue berry that is being cultivated for the climate in east Texas. We hope to slightly lower the pH of the soil with Juniper mulch and sulfur amendments and keep the swale moist enough to create a micro-climate that would allow us to grow Blue berries and other plants which otherwise could not be grown in this region. The quickest means of providing shade for our perennial food plants has been to allow native trees to voluntarily sprout up around our swales or assist them by tossing a handful of seeds into the swales each fall. Some of our healthiest fruit trees are growing right beside Toothache trees (or Prickly Ash, Zanthoxylum clava-herculis, its bark is used for toothaches and its berry tea is gargled for a sore throat or drunk to stimulate the kidneys), Cottonwoods and Hackberries. Initially, we considered digging up the native trees to give our fruit trees more light but after two years the fruit trees beside the native trees are doing the best and those in full sun are not doing nearly as well. Swales and shade alone, however, are not enough to meet the water needs of many plants while they are getting established. For the driest times of the year we still need ponds to collect and store reserves of surface water and a siphon hose to get the water from pond to swale.

A farm in Texas cannot have too many ponds. We have built eight over the course of two and a half years (five with a bull dozer, one with a back-hoe and one by hand) and we feel there is still plenty of pond work to be done. Even a small pond in a garden can add the calming presence of water and add tremendous diversity to your yard. A garden pond can easily sustain Cattails, Lilies, Bulrush, Wappato, Watercress, Duck weed, frogs, minnows, craw fish and much more. In front of our main building we have intertwined an herb spiral and a pond (both 5 feet in diameter) in the form of the yin yang pattern – the herb spiral is the yang (solid) and the pond is the yin (hollow). The whole design is under the shade of a Mesquite and is home to frogs, Cattail, Lilies, Purple coneflower, Yarrow, Thyme, Marigold, Oregano, Aloe vera and more. Together, the herb spiral and pond are analogous to mountain, hill, valley, lake and sea with many different aspects of sunlight, water depth and soil moisture. The source of water flow and aeration for the pond is our washing machine which our staff and interns use a couple of times a week. When the pond over flows which it regularly does the spill over irrigates an elderberry (Sambucus canadensis, used as a strong laxative), a fig tree and mesquite.

Between our ponds and swales there is too much surface area (2.5 acres) to irrigate or mulch so we rely on cover crops to shade and enrich the soil and conserve soil moisture. The hardiest cover crops for our region are Medicago (a native Burr clover), Vetch, Rye grass, Oats and Wheat sown early in September. In mid March we sow Cow peas, Millet and Sorghum. We mow once in the fall and once in the spring with a push mower right after sowing our seeds which is all we need to cut back the Johnson and Bermuda grasses. Any heavier machinery would do more harm than help by compressing the soil. After two years of cover cropping there are areas in our field where the ground now feels like a sponge and I even hesitate to tread there if I am wearing hard soled shoes or boots. We hope to soon produce significant yields of annual grains without weeding, tillage and the use of fertilizers and pesticides.

In our annual garden a surprisingly effective cover crop is Showy evening primrose which we initially planted for ornamentation but has since spread with a vengeance. Where our green manure plants do not cover the garden’s soil we use a light layer of grass clippings or horse manure. This light mulch will allow seeds to germinate through it and does not attract the armadillos looking for bugs as a heavier straw mulch will. When we water our garden we water all 750 square feet of it even where there are no vegetables growing. This is to further throw off the armadillos who will dig up the ground wherever we have spot watered in their search for bugs attracted to moist areas. Another voracious animal that frequents our garden is the raccoon who has eaten almost all of our corn three years in a row. This has been a fell blow for us who would like to cultivate the Three Sisters of North America – corn, beans and squash. We have yet to find a way to deal with this persistent critter and think perhaps an electric fence or guard dog might be the only solution. To protect the vegetables from high winds and the late afternoon sun we are establishing a border around the south and west side of the garden of Sage (Artemesia spp., used to induce sweating to break fevers and as a circulatory stimulant), Comfrey (used for skin treatments), Wormwood and Jerusalem artichoke. Not only will they buffer the winds, water run off and sun but they are quite useful in and of themselves.

There are countless ways to diffuse and harvest the natural flows of energy through the landscape. The best way to find out what works for you in your region is keen observation and lots of trial and error. When I make a mistake and am at my wit’s end because I will have to rebuild something or wait until next spring to try again, I try to remember what Mollison said to me after my first design course. “Now it’s time,” he said in his gruff, Aussie accent, “to go out and make as many mistakes as possible.” I think what he meant was, we should not be afraid to build or implement a design for fear of making a mistake, and that when we do make a mistake, which is inevitable, we should learn the lesson in that mistake, take heart and carry on. The most important thing is that we take the first step, then another and then another. Soon we are over half way to our goal, more experienced than we ever thought we would be, and having more fun than we ever dreamed we could have.

What you have in your mind?