Gardening in Hotter, Drier Environments

This post is going to serve as a reference post, for us and hopefully you the reader. Climate change has shown that many areas are going to experience changes in their regional weather pattern. Large parts of the US at the time of this writing are in drought, especially the Western US where it may even be entering a megadrought. For parts of central and west Texas this means that drought may be more common, longer, and punctuated with huge bouts of rainfall that dump inches of rain and then nothing for potentially weeks on end. We’ve been gardening for four years, with both successes and failures. In this post we’ll cover crops that have worked for us, how we keep up soil fertility and other soil health, and garden techniques.

This post is best suited for those in regions of west-central Texas, where the summers can reach 100F for days on end, where spring and fall are the wettest months, and the winters are relatively mild. No set of practices will work for everyone, and so it should be used to get idesa, trial out techniques, and add what works for your area. In the future, this will be updated from time to time as we learn more and adapt to our growing environment.

Choosing crops that fit your zone

Though it hasn’t been updated since 2012, even though it probably should in our opinion, the first step is finding the garden zone from the USDA. The region we’re in is 8a; historically it was 7b. In the next century, it may shift further down the numbers. When buying fruit trees and shrubs, many companies will reference the garden zone number. If you want to plan ahead by decades, consider choosing things that can tolerate a potentially warmer climate (such as if a blueberry plant is rated zones 5-8, consider the one that’s okay for zones 6-9 instead).

For the Abilene region, this zone is 8a. The rainfall historically is about 24-25 inches, with year-to-year variation. Snowfall is typically under 5 inches for the whole winter. Summer months are typically very dry, very windy. What has grown for us in this zone and when did we grow it?

Greens:

  • Spinach (Fall/Spring)
  • Carrots (Spring)
  • Cabbage and Greens both Western and Eastern (Spring/Fall)
  • Rutabaga (Spring)
  • Daikon radishes (Spring/Fall)
  • Potatoes (Spring)
  • Mustard Leaves (Fall)
  • Okra (Late Spring/Summer)
  • Tomatoes (Late Spring/Summer)
  • Japanese Eggplants (Summer)
  • Bell Peppers (Summer)
  • Winter Squash (Summer/Fall)
  • Spring Onions (Spring)

Grains:

  • Corn (Spring/Summer/Fall)
  • Sorghum (Late Spring/Summer)
  • Barley (Winter-sown to be harvested in late spring)
  • Wheat (Winter-sown to be harvested in late spring)
  • Sesame (Summer)
  • Millet (Spring/Fall)
  • Sunflowers (Work in progress this year)

Legumes:

  • Soybeans (Summer)
  • Peanuts (Summer)
  • Peas (Spring/Fall)
  • Yard-Long Beans (Work in progress this year)

Specific varieties will vary, but as a broad-level category, each of these has worked from moderately-well to really well. In the Greens section, okra, eggplant, radishes, carrots, spinach, and cabbages have all performed really well for us. In the grains, sorghum, wheat, and sesame have been outstanding. Sesame especially does well in the dry, hot summer. In legumes, they have all done satisfactorily, with peanuts being the our personal best.

An important factor to consider is choosing varieties that have as many of these characteristics as possible:

  • Early maturity
  • Drought tolerant
  • Heat tolerant
  • Disease resistance
  • Suitable for poorer soils

No one variety will be a super-star, but choosing varieties that have at least 2-3 of those characteristics is important. Okra for instance is good at drought tolerance, heat tolerance, and depending on the variety may have different disease resistance or suitability to poor soils. For cool-season plants, we tend to value early maturity and/or heat tolerance, as we like to try and beat the coming summer heat, but if spikes of high temperatures happen, it also doesn’t just out-right kill the plants. For warm-season plants, drought tolerance and heat tolerance is a key trait to look for, being able to withstand the hot, dry summer with less watering is always a bonus.

Soil: Type, Nutrients, Moisture Capabilities

Soils are very complex to say the least. Each garden’s soils will be very different in its ability to hold water, the amount of organic matter it can store, the nutrients that are within it, and the modifications made to it. The more clay your soil is, the more water it can store, but the less nutrients that are overall available. Similarly, the more sand, the less water it can store. Our garden sits on clay that’s really heavy. After a rain, it’s hard to go digging in the dirt if need be because the clay just sticks to everything. If you’re unsure what your soil is broadly, you can use the “Soil survey“.

To use the website, click the green “Start WSS” button. On the left side, go to Soil Survey Area. Select the state, then county. Click view and it should zoom in to your county. Then click on “Set AOI”. From here, at the top, go to Soil Map. Using the mouse, draw a square around the area you live in, zooming in until you get to your neighborhood. The labels are explained on the left side. Our property is two soil types: Rc and SaB, which according to the soil survey are clay loams. There’s other tabs and data you can look at as well. With this knowledge you can then look up information about your soil type.

Clay loams are good at nutrients and water retention and can support most garden crops. However, during periods of long times without water and/or high winds, the top layer will crust very readily, and on top of that, it will develop deep cracks into the soil itself. This has results in issues getting crops to emerge as the soil crust can rapidly thicken and prevent crop seedlings from coming out. An adaptation we have to do at times is to keep the top moist and wet during germination at all times. It can be balancing act as if there’s too much water applied, seeds can rot in cooler temperatures from this too.

One technique that has been beneficial at helping to lower the cracking of the soil and soil crusting is the use of compost. We covered composting in another post on the basics. Compost will help soil retain moisture, break up clay over time, and provide nutrients when applied to the beds. We put compost into the cracks that develop during the summer and water them in. During the winter, we apply a thin layer of compost on top of the garden beds and leave them to decompose in for planting later on. We also apply a small handful of compost into holes dug for transplants to help give a boost of nutrients. Over the past few years, the oldest garden beds have a better layer of dirt on top that is more easily dug to plant seeds.

Garden Techniques

Techniques used in the garden have to advance goals and objectives. In order to grow healthy plants, they require nutrients (compost), water, and disease prevention measures. Nutrients can be modified with compost as described above. Water can be conserved in the soil through soil type (clay) but it can be extended through a few techniques:

  • Mulching and Weeding
  • Lowering the Ground Level
  • Deep watering
  • Wide spacing
  • Minimizing wind erosion

Mulching is used in our garden to preserve the soil moisture underneath it. The sun will eventually dry out the ground, but mulch slows that process as well as keep the soil cooler. Mulching in the summer works well to help keep that soil a few degrees cooler, but in winter going into spring should be minimized to help warm the soil faster. The typical mulch we use is old hay or rained-on hay or even weeds. During the spring common ragweed is our most frequent weed, so we weed it from the bed and then leave it on top of the soil. It’ll decompose there over time and provide a mulch over the soil. Using weeds as mulch works best before the weed is seeding out. If the weed has seeds, don’t use as mulch or you’ll just reseed your garden bed with weeds. We also use mulch to line the garden bed exterior, this helps serves as a barrier between the “bed” and the “lawn”. During winter, this exterior hay will be pushed all into the center after compost is applied and allowed to sit til spring.

Lowering the ground level is inspired by “waffle beds” and other pit-like techniques, such as Zai used in Africa. We will space out the holes for seeds at the final seed length, dig a hole for the seeds and slightly deeper to make a pit, put in the seeds, cover, and water. Compost can be added into these holes to serve as a nutrition boost. Whenever it rains, the water will collect in the depressions, giving the area more moisture. The raised ledges also serve to help lower wind erosion, extending the moisture time-frame.

By going for the final spacing between plants at seed-planting, it also minimizes the disturbance of the soil. Tilling the soil will lower the moisture of the dirt, which in more wet-areas may be desirable if it’s interfering with planting in general. But for the arid areas, the tilling should be minimized for soil moisture conservation. We utilize tilling only on the first garden bed dig, where we incorporate compost into the dirt underneath. Beyond that, it’s only used to help get rid of the weedy Bermuda grass, quite persistent and tenacious. The final spacing also allows us to incorporate the wide-spacing technique.

Typical seed packages note spacing, but this may not be suffice in an area with limited rainfall and irrigation. In order to help conserve and extend the use of soil moisture then, wider-spacing must be used. The book “Gardening When it Counts” by S. Solomon details a few charts on their suggested spacing for a variety of plants in arid areas. Absent that book’s recommendations, we typically add 6 to 12 inches extra distance between plants and rows when planting big things such as large cabbages, corn, sorghum. As an example, if corn is recommended at a final spacing of 12 inches, we add 6 inches to make for 18 inches. For smaller plants like carrots and soybeans, we add 4 to 6 inches to the spacing.

The other advantage of wider spacing is the ease of weeding without damaging plants. The weeds do need more attention in wide-space systems as they are less likely to be covered by a canopy of leaves from the crops. However, a sharpened hoe can be easily navigated between plants to remove weeds. In areas with mulch, the mulch will also help smother the weeds too. All these techniques aid in retaining soil moisture. Which in turn means deep watering, either through rainfall or irrigation via hose, can be used once or twice a week to deliver a good, long water that lasts in the dirt for a long time. More frequent, lighter waterings may be used in between, especially on really hot days. If you have water and the plants are heat-stressed, it may be beneficial to water them some to get them through the afternoon.

When used in conjunction, the garden works better with the water it has. It may still need fertilizing and watering here and there, especially if it hasn’t rained for a few weeks. But by extending the soil moisture, it also encourages the plants to effectively utilize the moisture environment we have created to ensure it grows healthy. These techniques don’t aim for maximization of yields, it would be hard to with water as the limiting factor. These techniques are for persistence and survival of the garden. The goal for us should be that if we needed to go somewhere for a couple weeks, the garden should be able to be just fine without us watering it and continue growing.

Resources:
Dryland Farming: Crops & Techniques for Arid Regions (PDF)

Waffles in the Garden

Book: Gardening When it Counts – Growing Food in Hard Times

Where we buy most of our seeds:

Kitazawa Seed Company

  • Soybeans, yard-long beans, Chinese cabbages, sesame, winter squash, various greens,

Southern Exposure Seed Exchange

  • Okra, corn, tomatoes, sunflowers, books, tools

Johnny Seeds

  • Carrots, tomatoes, spinach

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