I overheard a conversation in a local nursery last week between a woman who was trying to buy the ‘right color’ hydrangea, and the nursery attendant who was trying to explain that color (for the mopheads, anyway) is all about soil acidity. I watched them lob phrases back and forth for a couple of minutes, but when it became clear the customer just wasn’t getting it I put on my Master Gardener hat and stepped in.
In less than a minute I was ready to scream. She just buys things and sticks them in the ground, she said; if they grow, they grow. If they don’t, she rips them out and buys something else. Get a book, take a class, for the love of God, learn something! It was on the tip of my tongue, and I’m actually rather proud of myself — not to mention a bit surprised — that I managed not to say it. Part of my reaction stems from my very Yankee background — we hate wasting money — and part of it is that, to a gardener, wasting good plant material is just wrong, on any number of levels. If you can’t be bothered to learn anything at all about gardening, buy a plant for your neighbor and then go cut your share of the flowers.
In lieu of that, here’s the five-minute drill on soil. Soil is composed of sand, which is pulverized rock, and organic matter, which is all the stuff that was formerly living and all the biotic life that feeds on the stuff that was formerly living. It usually also contains some degree of clay, which is composed of fine particles of silicates and other minerals. Along the coast here in southern Maine, because the land was under water for millennia we have a great deal of clay. This is harder to correct than soil that’s too sandy because clay is so dense; getting into it, breaking it up and amending it with the organic matter that will support plant growth is a bear. It’s a task I happily consign to boys — preferably good-looking, shirtless ones — with toys, because brute force is required, and I don’t have the back for it. Even if I did, there’s still the good-looking, shirtless part, and why spoil the fun?
Structurally, good garden soil is friable, a word that should mean ‘capable of being fried,’ but actually means ‘easily crumbled.’ When you squeeze a handful, it should hold together for a few seconds before falling apart. If it doesn’t hold together at all, it probably has too much sand; if it holds together longer, it probably has too much clay. Usually, you can tell good soil with just your eyes and nose: if it’s blond or grey, it needs organic matter. If it’s a good color but lacks that great, earthy scent, it needs organic matter. That’s compost, peat, desiccated manure and, my favorite, earthworms. Liquid fertilizer is fine for spot shots, but you can’t beat amending the soil. It allows water to flow, it allows the roots to branch; that in turn allows the plant to be secure in the ground, and to take up water and nutrient. If you’ve got organic matter in the soil, the earthworms will happily create little tunnels that allow roots to flourish, and they will do something else. They’ll poop, which will fertilize the soil and help it recharge. There’s also, of course, my preferred technique of soil management, which is planting the things that like the soil that you have. That means lavender and other woody herbs in sandy soil, and things that like their feet wet in areas with a clay base. That’s either laziness or practicality, I’m not quite sure.
Soil acidity is a different thing altogether. There are plants that want to be in ‘sweet’ soil, soil that registers on the ‘alkaline’ side of the ph scale; and there are plants that want to be in ‘sour’ soil, which is precisely what it sounds like: soil that registers high in acid content. Though there are many plants that are content to be somewhere in the middle, the bulk of plants that are really happy here in Maine are acid-lovers, and that’s no surprise, because Nature is no dummy. This state rests on a ledge of granite, which is why the pine trees came, and flourished; between the granite and the pine, we have some of the most acidic soil going. There are ways to reduce that, to sweeten it somewhat and bring it closer to neutral, but trying to grow plants that only do well in sweet soil is an exercise, perhaps not in futility, but certainly in frustration. If you really want to grow something that is foreign to your area and has a very particular ph demand, try a large pot or a raised bed, someplace where you can control soil. Sticking it in the ground, a la the woman who incited this discussion, will result in an unhappy plant, and an unhappy you, and life is way too short for either.
So there you have it; if you need more than this, get a book, take a class, or stay tuned to this blog.