Soil Analysis & Improvement
Soil analysis includes both a
physical examination of the soil as well as a chemical analysis.
The physical examination will determine what type of soil you are dealing with. There is a wide range of soil from sandy to silt to clay. The texture and composition of the soil impacts drainage. Soil texture is typically plotted across a triangle that measues the proportions of sand, silt, and clay. This determines the soil texture.
The type of soil may vary within a single landscape so your analysis should consider any different areas you are working in. Poor soil structures may need to be improved. Clay soils that do not drain well may be cultivated or may be amended by adding good soil to it. Soils that are dry may benefit from adding organic matter. This should be mixed into the soil as a whole and not on a spot basis.
Having a chemical analysis of the soils in your landscape will tell you if you need to amend the soil with lime or fertilizer and how much is needed. You can usually get a free soil analysis from your local county extension services. You can also purchase soil test kits.
Adding organic matter to individual planting holes for trees and shrubs is not recommended. The use of organic matter may make drainage worse and may actually encourage root systems to stay in the original planting hole rather than expand outward. Making a larger planting hole that is at least two times bigger than the root ball will provide a better alternative in allowing root systems to expand. Larger root systems allow the plants to absorb water more readily.
The purpose of soil analysis is to create soil that is ideal for plants to expand their root systems. Ideal soil has good aeration and drainage but still holds adequate moisture and nutrients needed for root growth. Your moisture requirements will be determined from the water use zones you determined during the Planning & Design principle. The principles are all interrelated. You created water use zones during the Planning & Design principle and now you have determined through Soil Analysis & Improvement what you need to do to create ideal soil conditions. You are now ready to consider Plant Selection.
As you explore other parts of the seven Xeriscape principles you will see how that are interrelated and how you need to consider them.
Continue exploring the seven principles: