A common problem in desert areas (such as parts of the southwestern United States) is caliche soil, which is a non-fertile substrate. People who have this problem and who wish to grow a lawn try all kinds of ways to improve caliche soil, but challenges abound. They may have dirt trucked in, but these are often sandy loams that end up getting hard and dry. They may also bring in compost, but that gets costly for large lawns.
How to Improve Caliche Soil
Caliche soil forms when the calcium carbonate in the ground fuses soil particles together. Instead of a nice, friable ground, you end up trying to plant in dirt that is impenetrable in places.
Caliche soils present a difficult set of circumstances in trying to grow a lawn. Common problems with caliche soils include the facts that they can create an impermeable layer that prevents water from draining properly through the profile, that they can foster the accumulation of salts in the profile, that they can limit root depth, and that they can contain an overly alkaline soil pH that prevents nutrient uptake. All of these issues may not be easily solved and can cause significant issues when trying to grow healthy lawn grass.
Lawn grasses typically will grow well in a soil pH range of from 6 to 7.5. Caliche soil can create unfavorable pH for lawn grass growth. The quality of caliche soils can vary widely, so you may want to send samples into your local county extension and have complete soil tests done to determine your specific soil conditions and determine the best plan forward. Most likely, though, you will have to do the following:
- Assuming that such tests reveal a pH level that is too high, you will have to fix that particular problem by adding sulfur to the ground.
- And amending the soil with compost provides a fix for the other problems posed by this type of soil.
The challenge, however, is that it is often impractical to amend the soil with compost across the entire extent of a huge lawn area. But there are some alternatives to look into here to reduce costs. Check with your town and surrounding towns; some public works departments offer free compost. You could also consider bringing in the materials needed to make your own compost, rather than buying costly, pre-made compost. For example, you can make an arrangement with certain restaurants to haul away a portion of their garbage; what is useless to them would be a blessing for your compost bin.
While no lawn grass will grow well in caliche conditions without proper soil amendment, buffalograss (Bouteloua dactyloides) may have a higher tolerance for these conditions and may be a good alternative, depending on your location. If your preference is for Kentucky bluegrass (Poa pratensis), tall fescue (Festuca arundinacea), or Bermudagrass (Cynodon dactylon), then 12 to 18 inches of soil amendment may be required. The soil test will provide you with good information to aid your decisions. No matter what species you select, proper maintenance will be important since growing conditions will not be ideal. First and foremost, your situation will probably require an automatic irrigation system.
Alternatives to Growing Lawn Grass
There is also a partial solution to the problem that involves making the following compromise:
- You will still be able to grow something in the space in question.
- It just will not be lawn grass.
The solution, in this case, is to grow xeriscaping plants. True, this solution does not furnish you with the lawn that you would prefer (under different circumstances). But there are two advantages in installing individual plants in this case, as opposed to a lawn:
- You can "pocket plant," meaning that you will require less compost. Instead of improving the soil across the entire space, you need to upgrade it only in the individual planting holes for the plants that you are using.
- If you live in a desert area, you are fighting nature in your attempts at growing a lawn, due to the lack of water available. By growing, instead, plants that do not require much water, such as many cacti and succulents, you are making your life easier.
Source: the lawn care experts at John Deere.
Managing Caliche in the Home Yard. The University of Arizona College of Agriculture and Life Sciences.
Growing Plants in Caliche Soils. New Mexico State University Cooperative Extension Service.