Regular soil testing forms the bedrock of an effective horticulture program. It allows us to diagnose real soil limitations related to nutrient levels, pH, soil texture, excess salts, and cation exchange capacity. From there, we can develop an accurate management program.
Test results can also indicate the presence of hazardous contaminants. Residential soils in Seattle are likely to be contaminated to some extent with arsenic and lead from historic use of leaded gasoline and arsenical pesticides, and especially due to emissions from the Tacoma and Harbor Island metal smelters. Determining the actual level of contamination in your soil can help you make the decision of whether or not to grow edible crops in your garden, or whether remediation is advised.
Using soil test results, we are able to develop a program of soil management to address specific limitations of garden soils. An effective management program can combine the use of compost additions, fertilization, pH adjustment, and inoculation.
Regular additions of compost can benefit soils by improving water retention and nutrient availability. Improved water retention leads to a reduction in environmentally problematic runoff and a real savings in costs of irrigation water. Greater nutrient availability = lush gardens using less fertilizer.
The general state of residential garden fertilization is at best haphazard. To set the record straight, in fertilization, more is not necessarily better. We simply need to make sure all nutrients are available in the proper ratios. Let's look at Bloom Boosters, the best selling fertilizers on the market. These are fertilizers with NPK ratios containing a high middle number, such as 0-50-0. That's a whole lot of excess phosphorous, which will not cause any increased blossom production in your plants, unless the soil was lacking phosphorous. Likely, it will runoff to local waterways and cause blooms of toxic cyanobacteria. Anybody like to swim in Green Lake?
The measure of where your soils rest on a continuum from acid-alkaline is called pH. Northwest soils tend toward the acidic. Knowing the pH allows us to correctly select plants for your soil type, or amend the soil pH to better suit existing plantings.
Soil inoculation is the introduction of desirable bacteria and/or fungi into garden soils. Plants form symbiotic relationships with a wide variety of microbial life. These plant-microbe associations can increase soil fertility, drought tolerance, and overall production rates. For example, certain bacteria can draw nitrogen straight out of the air and into the roots of plants. We're talking free fertilizer forever! Ask us about bringing your soil to life through better management today.