Using newspapers as weed supressant
As any gardener will know, keeping weeds at bay is perhaps one of the most challenging tasks we face in keeping decorative flower borders (unless you are lucky enough to have an army of garden helpers at your beck and call). For me being surrounded by nature is wonderful but slightly mixed blessing; I enjoy it enormously but the endless proximity to so much wild vegetation means that I am forever having weeds creeping into my borders. Simply put, weeds are any plant that is not welcome and inevitably I'm inundated with these. They come creeping in from the sides of the borders, spread by seed they invade any free surface of open soil, and as if that weren't enough they sometimes pop up from underneath having spread by far reaching rhizomes. I do use mulch to help me keep these invaders at bay, but often it is not enough. This is especially the case with invasive weeds such as couch grass, dandelion and horsetail that pop up again if even the smallest bit of root is left in the ground. To help me in my work, a few years ago I started using old newspapers as a weed suppressing layer while mulching in the garden and I have found that it is actually a very simple and effective tool for me. I use it both in existing beds where I am putting a new layer of mulch (A) as well as when making completely new borders or flower beds (B). The difference is that in existing beds I put the layer of newspapers on top of the soil underneath the mulch, while when making a new bed I make the layer beneath the new beds layer of topsoil.
A) Weed suppressant in an existing bed:
As you can see from the pictures above, all I do is spread out my collection of last years newspapers around the plants that I want to grow in the border. As newspaper decomposes quite slowly over the season, it is best to use only in such beds where you are not expecting existing plants to spread very much. If the bed is one in which much is happening, it is probably better to weed b y hand and only use a layer of compost as mulch. Otherwise the layer of newspapers will hinder the wanted plant growth of existing perennials unnecessary.
To get the newspaper sheets to stick to the ground instead of flying off if a breeze decides to pass by, I wet them in a bucket of water first. Once they are thoroughly wet they gain the heaviness to stay in place while I get a layer of mulch to top the bed off with. Depending on the location I will use different top mulches; if it is in a side border with lots of shrubs I often use wood chips and if it is in a flower border with more perennials than woody shrubs I use compost. The reason for this difference is that I tend to let my shrub borders be for the foreseeable future, whereas I tend to tweak the perennial borders at least a few times in the season. For example, in autumn I often fill up the perennial borders with bulbs due to flower next spring. Perhaps because the compost mulch tends to be wetter and more moisture retentive the newspapers decays faster and therefore it is easy to dig through the layer in the autumn and make room for the bulbs.
B) Starting a new bed or border:
As shown in these pictures above, when I begin a new border I layer materials upwards instead of digging down. For years I used to follow conventional garden practices and double dig two spade depths down, but then my back gave in and I realised that I had to accommodate my gardening desire to my handicap. What I have subsequently found is that by layering different materials upwards, eventually the grass (and weeds) underneath is killed by the lack of light and air. Although the plants underneath are killed, it doesn't seem to harm the soil underneath in the least. This is probably because the soil has micro life that spreads far and wide, and in fact it seems that the moisture and the decaying material beneath the layers are great for the worms as the really love it there. If there is a lot of stubborn couch grass I will make the bottom layer with both papers and organic weed suppressing fabric, but when it is on a simple lawn I just use a few layers of newspaper as a core. Then I add soil and compost before planting the area with perennials. As you can see from the pictures below, the flowers are thriving after just one season!
The use of newspapers as a weed suppressant is sometimes called sheet mulching or lasagna gardening because of the many layers it provides, and it is predominantly used in permaculture. There is some debate as to wether it harms the soil biology as it does reduce the exchange of oxygen and carbon dioxide between the soil and air. However, too few studies have been made to show if it is better or worse for the soil biology than digging down which also to a large extent disturbs the soil biology and existing micro life. As I find the soil underneath is filled with vitality, I am not so worried about these concerns but more concentrated on different experiments to see how I can improve this practice in my garden. This year I am also experimenting with a new area covered in layers of decaying leaves and next summer I hope to compare the two ways of starting new borders with each other. Until then, I shall keep you up to date of how my existing projects are going.
Happy gardening to you!