Soil & Soil Amendments

Every plant you plant is a living thing that requires nourishment. Plants get the nutrients they need from the soil in which they live. Well-nourished plants thrive, producing blooms, fruits and veggies. How, exactly, does soil do its job?

Soil holds various nutrients, the most important being nitrogen, phosphate and potassium. However, the texture of the soil determines how much of these nutrients are held for your plants. Likewise, soil drainage plays an important role in nutrient availability; some soil types drain very well, but that means they lose nutrients more quickly too.

Soil texture depends on composition or how much clay, silt and sand particles make up the soil. Sandy soil drains well, but loses nutrients and dries out quickly; clay, on the other hand, retains water and nutrients but plants have a harder time penetrating it with their roots.

The perfect soil type for your garden is loam. This wonder soil is composed of the right proportions of clay, silt and sand; you can easily identify it by the way it holds its shape when gently squeezed. You should give your soil a check-up every spring & fall before you plant; if it doesn’t pass, you can add organic matter or soil amendments to boost it back to perfect condition.

Check-up: pH

Just as your doctor examines you before treatment, you need to examine your soil before adding amendments. Poor drainage is easy to diagnose by looking at the soil; however, nutrient level is a different story. The key to determining your soil’s level is a pH test.

The pH level of your soil shows how well your plants are nourished by that soil. Neutral pH is between 6.2 and 7.2 on a scale of 1 to 14. A 7.0 is considered neutral, while results above 7.0 are alkaline or sweet and below 7.0 are acidic or sour. You can buy a soil testing kit or get one from your local co-op extension site. If your soil is acidic, you need to add lime; for alkaline soil, add sulphur. On the contrary, some plants prefer acidic soil. Azaleas and Camellias for example.  It’s a good idea to know what you are going to plant before adjusting your soils pH.

Treatment Plan

If you have existing beds with less-than-perfect soil, here’s how to fix it:

  • Using a steel rake or a garden fork, break up the soil around existing plants, going 2 to 3 inches deep. If there are larger chunks, break them up, too and then turn the soil.
  • You know what, if any, amendments your soil needs from the pH test. Sprinkle them over the soil and use your rake or fork to blend them in evenly.
  • Level the area by raking the soil in one direction. When done, rake it again in the opposite direction.
  • Once you’ve worked in the amendments, water your bed thoroughly.

If you’re creating new beds with less-than-perfect soil, follow these steps:

  • Start a few days before you plant by watering the area thoroughly. Wait until it’s dry again as wet soil is difficult to work and doesn’t always blend well with the amendments; you want to make sure the blending is even and dry soil is best.
  • Work the soil with a rotary hoe in parallel lines. Go over especially hard areas twice.
  • Apply the soil amendments you chose. Make sure they’re evenly spread.
  • Level the surface with a rake and follow up with a watering session.

 Prescription for Health

There are many choices available to make your soil healthier. This is a good thing because truly perfect soil isn’t always easy to find. Improving drainage and moisture retention, along with aeration and nutrient level is easy when you know how. Here are some amendments to bring your soil to optimum health:

  • Compost: Organic household scraps, fruit and veggies break down to make a great amendment. If you don’t compost, don’t worry; there are others.
  • Builder’s sand: Great for improving drainage; the grains, larger than beach sand, loosen the soil.
  • Compost manure: Odorless, this organic farm by-product is great for plant food and as enrichment for potting mix and seedbeds. Dehydrated manure is the same, only with less moisture.
  • Humus: This is a type of green manure created by growing soybeans or ryegrass during the winter. Plow them under in the spring and allow the natural decomposition to provide fertility, aeration and improved moisture retention. Dumping lawn clippings and raked leaves into a compost pile is another means of creating humus.
  • Limestone: If your soil is too acidic, adding this mining byproduct in the form of a natural white powder will fix it.
  • Sphagnum peat moss: This odorless, organic material is perfect for increasing water retention; it absorbs up to twenty times its dry weight, then “time releases” it into the soil. It also lightens heavy and aerates soils like clay and adds bulk to sandy soil which reduces nutrient loss. Sphagnum is an ingredient in mixes for container plants. Be careful to not confuse sphagnum peat moss with regular sphagnum moss; the latter is the type used by floral designers, not gardeners.
  • Topsoil: This is a commercially-produced compost that’s only partially decomposed. Its texture is rough, making it perfect for yards or as part of a mix; don’t use it as potting soil.
  • Potting soils: Perfect for gardening and seedbeds, these soils balance water retention and drainage quite well and produce great results.
  • Pre-packaged mixes:
    • All-inclusives are a blend of potting mix, fertilizer, pest control and moisture retainers. They’re great for container gardens and planting beds.
    • Potting mixes: These have organic matter in addition to aerators and moisture retainers such as perlite & vermiculite; they may even contain charcoal. They’re ideal for potting or repotting.
    • Professional grower’s or greenhouse mixes have a very fine texture perfect for starting seeds. Pay careful attention to watering though, as this fine texture causes it to dry out quickly.
    • Planting mixes are a mixture of compost, sand & sometimes other nutrients. They’re for outdoor use only, not for houseplants.

Some excellent choices for your garden are Family Tree Potting Soil or Topsoil, Organic Kellogg Topper or Gromulch and going beyond organic we have Malibu Compost – Bu’s Blend Biodynamic Compost , one of our top choices.