Most often the flowerbeds are made using curbs, which are essential for delimiting the flowerbeds and defining even more precisely the separation with the lawn and the rest of the garden. The curbs can be made in many different types of material, such as natural materials (stones, wood, stones) and construction materials (bricks, tuff, self-locking). Depending on the style and geometries we want to give our garden there may be several possible solutions, which we will try to illustrate in the paragraphs of this article.
How to prepare a flowerbed bordered by a curb
We can make a flower bed even on our own, preparing it when the lawn has already grown. However, if we have not yet sown the grass, we delimit the area where we want to create the bed with some stones and wait for the lawn to have sprouted before proceeding, preferring the installation of a few larger flowerbeds rather than many smaller ones, which would only confuse our garden. If, on the other hand, we already have a preexisting lawn, carve a perimeter of the future flowerbed with a knife, roll the clod thus obtained and let it interlace in another part of the garden where the grass is looser. If the shape of our flowerbed should be square or rectangular (keep in mind that narrow and elongated shapes are preferable), to trace the perimeter we can help ourselves with a straight rope stretched between two fairly close poles. We break up the earth in the centre of the flowerbed eliminating any pebbles and add plenty of soil for flowering plants. The plants that we will install must all be of the same species in order to bloom simultaneously, but choose them so that they give rise to flowers of different colours; we have them zig zag and not all in line so as not to give an impression of monotony. We can also plant pot plants together with our terracotta pots. We ask the nurseryman for advice from which we buy the plants because some prefer the shady grounds, others the sunnier ones. Some bulb plants grow a lot in height.
With time, some seeds carried by the wind could cause weeds to sprout among the seedlings which must be promptly eliminated; to overcome this drawback we can cover the soil with a layer of balls of volcanic material that can be purchased in nurseries that will prevent the flying seeds from reaching the underlying soil.
To better delimit the flowering area and prevent the lawn from expanding towards it and suffocating the flowering plants, it is advisable to insert a curb along the entire perimeter of the flowerbed. For this purpose, we have to arrange a trench 20 centimetres wide and 15 centimetres deep all around, on the bottom of which a thin layer of coarse sand should be laid first. After placing the curb the ground on both sides must be pressed well, so in the following thirty-six hours you must avoid nearby irrigation and keep children and animals away. The curbs are commercially available in heights ranging from eight to twenty-five centimetres, are available in different shades of colour and must obviously withstand the erosive action of atmospheric agents.
With the curbs, we can create an even more complete garden by using them to also trim relaxation areas with benches or small ponds and streams.
Curbs in natural materials
The curb can be made of stone, but not simply by collecting stones in the river below the house and placing them side by side, because in the spaces between one and the other the soil would tend to leak out, especially if the garden is downhill , and the grass of the neighbouring meadow to penetrate the flowerbed. The stones that make up the curb must be made so that they fit perfectly together and create a continuous and homogeneous barrier.
The rocks normally used are marble, granite, porphyry, Trani stone and tuff. The latter is the most used, of volcanic origin, extremely light and porous; it can be found on the market in different colours, it is cheap and can be easily cut. However, it involves the defect that, even if it is covered with breathable plaster, water can penetrate its pores with consequent growth of grass on its surface and its duration is less than that of other rocks.
A curb can also be created with woven wood or wicker that can be purchased in nurseries, but termites and rotting will easily degrade it within two or three years.
Curbs in artificial materials
The metal curb is easily attacked by rust and requires maintenance that not all of us have time to perform.
If instead, you use terracotta bricks you will soon have the problem of the growth of unsightly grass and breakage due to the action of frost and thaw.
There is an artificial material called “reconstructed stone” consisting of ninety per cent of grit and marble dust, quartz and special binders which possesses exactly all the characteristics, exterior and strength, of natural stone with the advantage of costing a little less.
However, cement is the most widely used artificial material for making curbs. It is inexpensive, does not chip or rust and requires no maintenance. The colours with the use of this material have a very long life because they are added to the mixture, not subsequently painted, and additionally fixed with a sealant. For small round flowerbeds, there are also commercially available curbs in this material made up of two semicircles which can be joined together with few gestures. Where greater resistance to crushing is required, for example, if the curb also marks a driveway or a cycle path, it is possible to insert steel reinforcement in the mixture.
By adding to the crushed stone the concrete is obtained, a material that can be poured from a machine creating a continuous edge very similar to natural rock.
For the flowerbeds that border public places are also used cold-pressed recycled tires, with which an elastic, resistant and paintable bead are obtained.