Provo City

Soil Considerations

Tree Care
Soil Type
Although it may appear that the soil around your home is just a heap of dirt, it is actually a very organized and structured medium, ideally suited for root growth. Soil is composed of three different sized particles: sand, silt, and clay. These particles cause different soil textures. Soil texture is responsible for the soil’s ability to hold water and provide oxygen to the roots. Certain soil textures are preferred by some trees. Before selecting a tree for your yard, make sure it is suited to type of soil found there.  

  
Compaction
Soil has structure. It is made up of clumps or particles and air pockets, or pores. Ideally, soil should be about 50% pore space. Roots need this pore space to access air and water, which are essential for root development. When a soil is compacted, the soil aggregates are squished together and the pore space significantly shrinks. Compaction can be the product of heavy construction equipment or just regular pedestrian traffic. Regardless of the cause, when compaction occurs the roots suffer from a lack of oxygen and poor water infiltration. As a result, tree growth is greatly reduced. Serious drainage problems can also be a byproduct of compaction.

Solutions
  • Vertical Mulching: Holes drilled throughout the root system to improve aeration. Holes are made at least 3 feet from the trunk of the tree and are usually 1 foot deep. They are 3-5 inches wide. 
  • Aeration: Aerate the soil. When aerating around trees be careful not in injure tree roots. Always keep the aerator at least 3 feet away from the trunk of the tree.
  • Prevention: Often compaction can be prevented, especially during construction. Rope off areas around trees. Redirect traffic. Place mulch or mulch like mats to minimize the effects.
 
pH
The pH of a soil refers to its acidity or alkalinity. Some plants require or favor a specific soil pH, but many plants grow in a broad pH range. Most soils in Utah are alkaline with an average pH of 8. Although slightly acidic soils are typically ideal for most plants, a pH of 7-8 is okay for many. Plants suited to arid regions seem to be especially tolerant of a higher pH. It is much easier and less expensive to live with a slightly alkaline soil than it is to change it. Often attempts to alter soil pH are ineffective. This is especially true in Utah were most of the irrigation water available is already alkaline. 

  
Salty Soils
Soils contain a mixture of salts. Those that contain high concentrations of soluble salts are called saline. Salts can build up in a soil from irrigation water, deicing salts, and other sources. Plants vary widely in their saline tolerance. If saline soil is a problem in your yard, you can plant more salt tolerant plants. Proper drainage in your yard may also leach out some of the excess salts. For more information, please contact us.