Soil: A Dirty Four Letter Word

Kim Halberg, Extension Master Gardener, Anoka County

So what’s the big deal about soil anyway? Everything. Whether you aspire to a robust vegetable garden, or a thriving landscape of trees, shrubs and ornamental plants set off by emerald turf, understanding the basics of soil is a must for success.  An open discussion about dirty four letter words such as loam and humus is important.

Soil is made up of texture, moisture, nutrients and pH value that work together to promote healthy plant growth. Soil texture consists of three main types: clay, silt and sand.

The predominate texture of soil in Anoka County is fine sand; fast draining with an acidic pH range of 6.1 to 7.3. Exceptions to this would be the areas around Burns Township and along the Mississippi River. What does this mean for you as a homeowner? Sandy soil has good irrigation, is easy to work with, and allows for plenty of air for warming up and the extension of plant roots. However, this also means the soil dries out faster, eliminating essential nutrients needed for optimum plant growth.

The goal is to achieve the sweet spot of soil texture known as loam. In the words of Goldilocks, it’s neither too hard (clay) nor too soft (sand), but just right. By regular addition of organic matter to our Anoka County sand, we can help our soil retain moisture and nutrients. Just as dead leaves become part of the forest floor, organic matter of decayed plant and animal remains slowly become part of soil.

Have you ever thought of saying “thank you” to an earthworm? Living organisms such as insects, earthworms, fungi, and bacteria are considered part of organic matter. They are working hard on your behalf to churn and digest organic matter into nutrient rich humus that will not break down any further. Another organic matter is mulch, which will break down in time: straw, grass clippings, shredded leaves, sawdust, newspaper, pine needles, wood chips and bark.

Work organic matter or compost into the sandy soil annually until it feels loamy, a texture that will allow air (a bit of fluff) and retain moisture without clogging up root systems, preventing roots from reaching toward needed minerals. Using less water is also good for our utility bill and the environment. Lawns can be top dressed and grass clippings left to add nitrogen.

Organic matter can be purchased at a local store, a local compost place, or dug from your own compost pile. For more information about compost visit the U of M Extension Garden Website:  http://www1.extension.ums.edu/garden. Soil testing is also recommended for accurate application of organic matter and fertilizers, which can be found at http://soiltest.cfans.umn.edu/ .

Search out a list of recommended plants for Anoka County. Even after careful addition of soil amendments, the cardinal rule of “the right plant in the right place” should be observed. One last look at SOIL: Sandy texture in Anoka County, Organic matter does matter, Irrigation water not wasted, Let in air and Let roots find nutrients. Time to get dirty!