Healthy soil makes for healthy plants; and fruit and vegetable crops depend on rich soil with good drainage. Making sure you start with good soil is one of the most important first steps when starting a foodscape. A garden’s soil provides so much to plants: water, oxygen, macro and micro nutrients, not to mention anchorage to hold plants upright. If you are in Utah or another arid climate of the western US, our soils have some advantages and disadvantages. Chances are your soil has a decent amount of mineral nutrients, unless it is particularly sandy. Utah soils usually have sufficient phosphorus and potassium, as well as most trace elements. On the other hand, Utah soils are usually lacking in organic matter. According to Utah State University (USU) Extension (see references below), an average soil contains 5% organic matter, whereas Utah soils typically contain less than 1%. Some areas of Utah also have particularly heavy clay soils with a high pH. Food crops struggle when soils are too heavy or too alkaline. One way to make sure you start with good soil is a soil sample analysis. We used USU’s Analytical Laboratories and it was very easy. Utah residents can check out a soil sample probe from a local county extension office and then mail soil samples to their lab in Logan. When we tested our soil, we spent about $25 and an hour collecting samples and had our soil analysis in a week or so. If you indicate what crops you plan on growing, USU labs will also make specific recommendations for soil amendments.
Additions of organic matter (usually through compost or manure) make an enormous difference, particularly in Utah and other arid climates. Compost drastically improves drainage in heavy clay soils and increases water and nutrient retention in sandy soils. Compost feeds micro-organisms as it breaks down which releases plant nutrients. It adds structure to the soil for roots to grow and develop. It also helps prevent soil compaction. Soils that have a high percentage of composted organic matter are healthy and rich…no wonder compost is called black gold! In addition to making our own compost, we get compost by the pickup full from our city’s green waste facility. It has worked wonderfully.
There are many ways garden beds can be prepared. We have had success both with and without raised beds. If you are starting with decent soil, you do not necessarily need to build a raised bed (although it still has many advantages, -less weed pressure, less bending over, faster warming in the spring, etc). We created our first beds at soil level simply by establishing walking paths around them and incorporating large amounts of organic matter (compost, grass clippings, leaves, etc) into our native soil. If you have a good source, it is hard to add too much compost. When we started, we added four inches of compost and mixed it in to a depth of 8 to 10 inches using a garden fork. An initial large addition of compost will help get your garden off to a great start. Additions in subsequent years do not need to be so large. Fantastic soil is built over the years by adding composted organic matter. Fall is the best time to add compost because earth worms will help incorporate it in the soil and any excess salts will have time to drain. Fall is also a great time to add brown leaves and coffee grounds, because they can be sourced for free and have time to break down. For our established beds we add mulched leaves and coffee grounds and then simply top with an inch or two of compost every fall without tilling or mixing it in. While fall might be the best time to add compost, assuming you have a source of good compost (finished decomposing-smells like soil, not high in salt), there is never really a bad time!
-To see how we filled several raised beds in the fall by adding tons of brown leaves and free coffee grounds, see our Video: Foodscaping Our Frontyard