When experienced gardeners talk about making a new garden, one of the first things that they often talk about is improving the soil. But for those to whom gardening is entirely new, this phrase can be a little bewildering. If you are new to gardening, have just ordered your polytunnel or are about to do so, and are wondering how you can improve the soil in your polytunnel, here are some basics to help you to get started on the right foot.
The first thing to do is to determine what your soil is like. You can work out what it is – clay, silt, sand etc... and its pH. Looking at the things already growing in your garden can give you some clues about what good and bad qualities your soil may have. No one expects you to learn it all overnight, but you are looking to establish the basics – how fertile is your soil and how many nutrients does it contain? How well does your soil store water or allow water to drain?
There are several reasons why we want to improve the soil. The first reason is to improve the nutrient profile and make sure it has enough 'food' to feed growing plants. The second reason is to improve the soils ability to retain water, or allow it to drain. The third reason is to make sure that the soil ecosystem functions as it should. The soil and its creatures make up a living ecosystem just like any other and when things are wrong or out of balance, everything – including your plants – will suffer.
Once you have spent some time examining the soil in your garden, you will be able to answer questions about it and determine which problems you will need to address. For example, if you have a heavy clay soil, you will likely have a good nutrient profile but will need to address issues of waterlogging and compression (when the soil packs down hard and plant roots can lose the oxygen they need). Another example is a sandy soil, which is low in nutrients and extremely free draining. For both problems, however, the answer is the same – add organic matter.
When starting a new garden, one of the first things you should do, before you even think about getting any seeds, is starting a compost system to create your own compost. In the future you will be able to use that compost to improve your soil. Simply layer compost on top of your soil and over time, the soil will improve. You can and should also layer on mulches, such as grass clippings, or leaves. As these break down they will add both nutrients and humus to your soil and improve it.
Improving soil in basic ways does not take a genius, but it does take time. Start with the correct practices right away and you will be headed in the right direction from day one. Improving the soil is not a one-off event but a continual gardening practice. Remember this and you cannot go too far wrong.