| Principle #2Condition Your Soil Through Soil ImprovementsGrow Good Soil
  Improving
                           your soil is one of the best investments you can make
                          
                          toward a successful landscape. One common ailment of
                           most western soils is that they are low in organic
                          materials 
                          and have a high pH, meaning that they are alkaline.
                           High alkalinity reduces essential soil elements needed
                          
                          for proper plant growth. Many soils around the built
                           environment also suffer from compaction created by
                          foot 
                          traffic, auto traffic, and machinery traffic during
                           construction. Compaction restricts the movement of
                          air 
                          and water which is essential for good root development.
                           Good root development is a key factor in the ability
                          
                          of a plant to withstand drought conditions. Adding
                          an  inch or two of compost, peat moss, or aged manure
                          rototilled 
                          thoroughly to a depth of six inches will help to improve
                           the soil structure and moisture-retaining capacity
                          while 
                          buffering the soil alkalinity. Another common problem
                           with soils in our area is that soils are too sandy
                          or 
                          too heavy with clay. To help alleviate this problem
                           use the same approach. Organic material in clay soils
                          
                          will improve the soil’s ability to release more
                           water to plants and will allow air movement. The same
                          
                          amendment in sandy soils will help it to hold water
                           for longer periods of time. Remember that organic material such as in any soil 
                          is the primary source of nutrients to plants. The addition 
                          of aged organic materials such as compost, aged sawdust 
                          or manure also “inoculates” the soil with 
                          colonies of beneficial bacteria. These bacteria help 
                          to speed the decomposition rates of organic materials 
                          in the soil. Over time this process actually “grows” 
                          good soil.  
                          
                            | Planting StrategyWhen planting large trees dig the tree hole 3 
                                times the diameter of the root ball and exactly 
                                as deep as the root ball. Set the root ball on 
                                undisturbed soil at the bottom of the hole. This 
                                will prevent settling of the root ball. Do not 
                                amend the backfill. Contrary to popular belief, 
                                amending the backfill will encourage roots to 
                                stay within the planting hole rather than expanding 
                                outward into native soils. The hole is dug 3 times 
                                the diameter of the root ball because the loosened 
                                soil around the root ball will allow better movement 
                                of air and water, which stimulates root growth 
                                to explore the native soil surrounding the tree 
                                hole.
 
 Soil Amendments TipMany native plants do better with no soil improvements. 
                                Use amendments only with appropriate non-native, 
                                adapted plants. Typically soil amendments should 
                                be focused in the High Water Use Zone and Moderate 
                                Water Use Zone. Soils in turf areas, especially 
                                bluegrass, should always be amended.
 
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