Do you ever get slightly dismayed by the copious amounts of compost stacked high in garden centres? Do you look at the soil in your garden and wonder why it never does anything you want it to?
Well today I though I’d share a few points around this rather mysterious organic growing matter.
Question – What’s the difference between soil, compost and mud?
Answer – nothing it’s just a name by which we call the very ground we walk on. It is a descriptive set of words to also determine the structure of the soil (we’ll get onto that a bit later).
Not all soil is created equal.
It comes in very different states, made up by thousands of years of lying about (so to speak) and it’s very make up (or particle size) determine what you can grow, when, and how you can grow anything you put into it.
So by and large I thought it time we got down to the ground and made mud easy to understand.
If like me you’ve ever decided to start digging over a patch of ground in your garden you’ve probably wondered why the hell it’s either so easy to dig that nothing sticks to the fork, or impossible to dig and your left caked in wet mud. And why the hell does it never look like the soil they turn over in all those gardening programs?
Well it all comes down to the structure of the soil. There are basically three types of soil in the world:
- Sandy – While extremely easy to fork over you tend to find plants not doing so well in these structures because there is nothing for the roots to hold on to to be able to draw much needed nutrients from, which is just as well because there aren’t that many to take anyway. It very often sinks and doesn’t hold any structure. Even when water is added it soon dries out and moves – just like a sandcastle.
- Clay – By comparison clay soil is heavy and sticks to everything. A plant has no problem getting what it needs. In fact very often it has too much of a good thing and ends up being over watered to the point of drowning because the soil takes so long to drain.
- Loam – This is the ultimate, optimum soil structure. It’s crumble without being too free draining and holds the required amount of nutrients longer than the other two types of soil because it’s a mixture of both structures above. It is easy to dig and easy to plant with. This is the soil you’re going to always aim for when growing anything, and it’s completely possible to do but you’ve got to spend some time getting there because it’s hard to find, even when bought in bags from the garden centre.
If you’re growing anything from scratch in your garden chances are you’ll pop to your local garden centre and pick up a bag of compost.
Compost is called compost, rather than soil (even though it is soil) because it’s designed specifically for a purpose other than walking on. Compost is like buying a bag of ready made growing medium. It basically has everything you ever need for the plant (or seeds) to start growing and the contents, made up of minerals and fertilizers, will last for anywhere between 4-8 weeks until the all the good nutrients are washed out by the rain and regular watering.
That’s why I said above it’s hard to keep the soil in loam condition!
Back to Soil
When we talk about soil we mean anything outside found in flower beds, lawns, raised beds, allotments and by it’s very nature anywhere that is’t covered with concrete. Any soil can be cultivated but first you have to know why you need to cultivate it. Soil is a basic material that binds roots of a plant together. As the roots bind with the soil the plant is then able to draw essential water and nutrients through the cells of the roots and spread it up the stem and along all branches and leaves. If the plant is unable to find the necessary nutrients, or indeed water, then it simply dies – death by starvation, and no one wants to see that happen.
The magical nutrients are a combination of three different things – moisture, minerals and the PH of the soil.
Soil PH is a chemistry measure to determine how acidic or alkaline the make up of the soil is. The scale ranges from less than 3.5 which is acid to greater than 9 which is all alkaline. Only very few plants can survive in either extremes of the scale. The length to which a soil becomes alkaline or acid is determined by either it’s location, the weather, near by industry, how old the soil is and of course – whether anything is added to it (compost). For instance if the soil is naturally located near to high coal industrial areas the water that the soil takes up will be very alkaline based. On the other hand if the soil is located close to areas of heavy rainfall it will be on the acidic side.
Did you know pure water is on the scale at 7.0?
The ideal soil PH would be anywhere between 6.1 and 7.0. At this level plants are perfectly suited, ready to be able to take up nutrients given in the structure and will happily grow.
Anything below and above this level needs some work doing to it to bring it up to the ideal levels.
Don’t worry if you don’t know the levels exactly – any major imbalance would soon show up on your plants growth (or lack of). Signs of yellowing leaves, lack of flowers, stunted growth and blooms with odd colours will all be a cause of the PH and the lack of nutrients.
So as we now know what structure we need and what level of PH is best for growing conditions, now we need to attain it!
Soil nutrients can sometimes be rather confusing – especially when you’re confronted with a zillion and one packs, liquids and powders at the garden centre all offering different enhancements to your plants.
However it all boils down to four major organic/non-organic nutrients:
- Calcium and magnesium
All fertilizers found as liquids and powders will be made up of varying proportions of the four main nutrients and displayed by numbers on the packaging. For instance tomato feed usually has the numbers N:P:K 6:3:10 on it. This means it’s made up of 6 parts nitrogen, 3 parts phosphorus and 10 parts potassium (aka potash) and is the perfect balance for ensuring plants grow healthy and strong. However this kind of feed will not keep the soil stucture maintained nor will it help keep the nutrients locked in for long so you have to start adding to the soil before you add in any plants.
Bonemeal, manure, lime and fish and blood are other big sources of organic materials that can be added before any planting takes place and will not only add the much needed nutrients to your soil, but can change the PH levels and more importantly change the structure of the soil. Manure is a very good example of this.
Manure helps to breakdown the structure of very heavy clay soil, and it can also help to bind very loose sandy soil. It’s well worth investing in this for any vegetable planting as it will help to get the texture of the soil much more workable and get those plants growing and feeding from the soil to produce abundant fruits.
So next time you look at turning over some soil in your cultivation patch remember three things:
- If it feels too heavy or to light to dig, add in some organic fertilizer
- Test the soil before planting anything that requires a more acidic PH levels (Many shrubs and tree’s prefer soil on the acidic side)
- Remember to keep topping up the soil with organic nutrients once the plants are established
And I haven’t even mentioned the worms! I’ll save that for another day…
Cover photo courtesy of Michael Randall