Confused about gardening and want to learn more? This is a new weekly addition to the Behnke Blog that will try to simplify gardening terms and concepts in a user-friendly way, maybe toss in the occasional joke or a simple weekend project. Send questions and I’ll try to answer them.

Let’s assume you have a pretty good concept of what a plant is, because I don’t want to get into defining something you already pretty much take for granted. Plants mostly grow in the ground, although some grow in water or cling to trees or rocks. But for the most part, plants grow in the ground. Not in the dirt. We plant folks prefer the term “soil”, which sounds pleasant, as opposed to “dirt” which is what soil becomes when it’s under your fingernails or on the knees of your pants.

So, when a plant is in the ground, it’s in the soil. Folks who study soil chemistry and so on are “soil scientists.” Soil is made up of little bits of stone. Depending on how big the little bits are, and how they are mixed, it can be sand, silt or clay (from coarse bits to very fine bits). In addition to the stone, you usuall have some decaying or decayed plant or animal bits (called organic matter) and depending on the proportions of the stone bits and the organic bits, you get additional soil classes like a silt loam.

The type of soil you have has a big effect on how well things grow in your garden, and in the future, we’ll talk more about that. A sad little part of life is that, when your house was built, the builder probably scraped off the best soil, the topsoil (that is, the soil next to the air) and sold it, replacing it with the soil that came out of the hole for your basement. This soil is not particularly hospitable to plants. Even Zombies claw their way out of it to get to the surface. But, it’s what you’re stuck with. We’ll also talk more about how to improve your soil or bypass it by using containers or raised beds.

Finally, potting soil. Real soil from the ground is not good for use in pots, because a) it is heavy and hard to handle, and b) when you water, it doesn’t drain very well (so the soil stays too wet, there isn’t enough air in the soil, the plant’s roots rot, and your favorite philodendron goes belly up). So potting soil is an artificial soil, a mix of stuff that works well for plants in pots. It’s made of stuff including peat moss, coconut shell fiber, and so on. Ingredients not really important to you as a beginning gardener. (There is some controversy on the peat part, which is mined from peat bogs. This is an environmental issue beyond the scope of this article.)

When we want to show off, we plant guys toss around terms like “soil less mix” (no soil) or potting medium (plural media). So when you go to the garden center, pick out some flowers and a pot, and the hortie says, “You need to plant your marigolds in a well-draining soil less medium,” they mean, use a good commercial potting soil.

A hint: when shopping, lift the potting soil bag. In my experience, for equal sized bags, if it’s heavy, it’s better for use outdoors.  If it’s light, it’s better for use indoors. This is assuming you are starting with a dry bag of soil and not one that has been sitting out in the rain for three months, of course. The heavy mixes hold more water. Pots outdoors tend to dry out faster, and the light mixes may require more watering than you want to provide, especially as the plants get bigger and the days get hotter.

Hope this helps!!

Larry Hurley, Behnke Nurseries

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