Amending soil

The recipe for perfect soil is an easy one – one- third dirt, one -third sharp sand, one-third compost. Would that all recipes were this easy.

If you have decided that your dirt is so awful you can’t use it, you can probably find a local company that will deliver the above mix. You will need to know how many cubic yards you want, so measure your space, decide how deep you want your new bed to be and do your multiplication – length X width X depth ( make sure all measurements are converted to feet); then, since there are 27 cubic feet in a cubic yard, divide your result by 27 and presto! – the number of cubic yards you need. And, ps, the depth of your bed, if it will be planted with perennials (plants that come back every year or live for years) or vegetables, should be at least 12 inches. If it’s a bed for annuals, you can get by with 8 or 10 inches since the plants won’t last for more than a season.

Fixing It

If you decide to amend your next step will depend upon what type of soil you already have. If it’s acid, add lime (calcium carbonate ) –  following  the test lab’s recommendations; if it’s alkaline, add sulfur, again to the lab’s specifications or those of your county extension service.  If  it’s sandy you’ll need to add compost and dirt. If its clay you’ll need to lighten it up with sharp sand and lots and lots of compost. ie., organic material.  You can buy compost or make your own – but when you go to buy it you will often find it marked as mulch. Not all mulches are compost but all compost can be mulch. If you’re confused about the terminology its simple – if its going on top of the ground, its mulch; if its going into the ground, its compost. Unless you’re top dressing with compost.

Mulch is meant to go on top of the soil to conserve moisture, prevent weeds from sprouting and, in cold climates, to insulate the ground in winter.  It will also help to keep the roots cool in hot weather. Mulch can be plastic (yuck), straw, grass clippings, bark, chopped leaves, gravel, newspapers – any number of things. Please avoid the cocoa mulch sold at some garden centers, as it is extremely attractive to dogs and can kill them.  Mulch composed of organic matter is best. Compost is meant to be a soil additive that will improve the quality and texture of the soil.  The condition of your soil, especially if you plan to garden organically, is critical – it isn’t just a growing medium, it’s a living organism. It is full of microorganisms and nutrients that must be constantly replenished and nourished. Since you won’t be using chemical sprays or fertilizers (I hope), you must see to the health of your soil. Chemicals are a quick fix but not a good long term solution any more than you taking carb blockers so you can live on fries instead of eating a healthy diet is a good idea. Chemicals actually impact the soil in unfortunate ways – they kill microorganisms, discourage good things like earth worms, leave mineral salts behind and kill beneficial insects as well as bad bugs. Using them means your dirt won’t be alive. It will just – well, lie there. Think of your soil as a partner in your garden and you’ll both be better off.

Ok, assuming you’ve found your soil type and texture the last thing to check is drainage. Poor drainage can kill plants very quickly so it’s important to know if you have a problem. Dig a hole about two feet deep in your chosen plot and fill it with water; after it drains refill it. Check back in about an hour – if there’s still water in the hole, you have a drainage problem.  That means you will have to amend your soil to a deeper level or use raised beds, which we will cover later in the post. Poor drainage is usually caused by hardpan – a thin to thick layer under the top soil that is virtually impermeable. It can occur naturally, as it does in my area of the southwest, where it’s called caliche, or because builders have put down a layer of soil and driven heavy equipment over it while working on the site. If the hardpan is thin you might be able to have the area plowed or break through it with an augur in the spots you want to plant; you will need to work in lots of organic material to improve it but it can be done. If it’s thick, as it can be here – we sometimes have to use a tool called a sharpshooter – you would probably have to hire a contractor to install a subsurface drainage system. In that case, raised beds would be both easier and cheaper unless you’re planting acreage.

In my next post I will discuss the two ways to start off – the hard way and the easy way. The hard way entails a process called double digging or double trenching, and will probably drastically improve your relationship with your chiropractor and dramatically increase his profits; the easy way entails the use of raised beds or sunken beds, and while it can be more expensive, if you count what you’ll save on the back doctor, maybe not so much.

FINDING THE pH OF YOUR SOIL

Soil pH simply means the range of acidity to alkalinity of your dirt. If you don’t know your soil type, you can buy a test kit and find out. Or you can try calling your county extension service – they can be a wonderful resource for many things agricultural – and ask them for help. Most plants prefer a fairly neutral soil, so on a large scale you would want a pH of around 7.

SOIL AMENDMENT

Soils can be amended and most will need to be. But trying to change an alkaline soil into an acid one, for instance, would, on a large scale, be a major job and would require constant labor. If you have alkaline soil and want to grow acid loving plants, I suggest you confine them to one small bed or containers. And if your water is alkaline as well, you’ll be fighting a losing battle unless you’re willing to water your plants with  bottled water.

Soil amendment is usually confined to texture. Perfect garden loam rarely exists in home gardens. Most soil is too sandy, is clay, is too rocky or too compacted. With soil, after pH, texture and type are everything.

SOIL TEXTURE

The texture of a soil determines its viablility as a growing medium and there are three basic types – clay, sand and loam. Head out to an existing area where you want to plant and water it. Twenty-four hours later go back and pick up a handful of your dirt and squeeze it. If it clumps together in a sticky ball you have clay soil. If it crumbles you have sandy soil. If it is a bit crumbly but sticks together loosely – congratulations, you have loam, the perfect gardening soil.

In my next post I will discuss what to do to fix your soil, and most of you will need to fix it.  So sorry. Just remember, if you get it right the first time you’ll avoid spending hours and hours for years and years trying to compensate for bad dirt.