Given enough time, and inclination, one can amass a vast knowledge on the subject of soil. Perhaps too much, but then I’d have nothing to blog about, so join me now on a journey into the ground beneath our feet. Metaphorically speaking, of course, I won’t be covering carpet, laminate, or any other flooring you settled on in your home.
Soil is not dirt, lets start there. Soil is a combination of several ingredients which may, or may not, include dirt. For example, potting MIX contains no dirt, while potting SOIL does. And you thought you were already lost in the gardening department 🙂
Dirt is, in a basic way, crushed rocks. Finer the crush, finer the dirt. Fill dirt, like you see on Craigslist, contains more gravel and rock than a garden dirt. Most of us either have all the dirt we need, or need to grow plants in a virtually dirt-free environment, like patio and balcony gardens.
Soil generally comes in two forms – potting and garden. Plants in containers need a lighter, less “dirt” mix with heavy drainage. You’ll often find potting mix made from compost, vermiculite and manure – a light, well drained base. Garden soil, in contrasts, tends to have heavier ingredients like worm casings and dirt. These retain the moisture and help plants root into the soil.
On to mulch. Mulch retains water.. Sort of. Applied properly, mulch lets water flow easily past it, to the roots of plants below. It provides a cover, over the soil, that keeps the water from evaporating as quickly. With any mulch, lay a 2-2.5″ layer and plan to replenish annually.
There are three main types of mulch. Forest floor, shown below, is a coarser chop. It’s meant for pathways and around shrubs and trees. There is a more “chopped” or shredded mulch, used in garden beds and planters. Then there’s heavy mulch, using straw or shavings. Used mainly in colder regions, it keeps the soil warm into fall, allowing late season harvests of onions, carrots, potatoes and garlic. I use all three in my garden and I’ll go over their uses in more detail in a future blog post.
The main thing to remember is all types of soil, from potting mix to mulch, are decomposing as your plant grows. Manure and mulch give off perceptible heat from this process that can damage some plants. Most, though, love to be wrapped in a snug layer of ground up trees.