Starting the Landscape Design in Your New Garden
Give plenty of time and thought to these early deliberations because they can save much regret and work later. However, the time has come to put theory into practice and make first contact with the. If the garden is on level land there should be no need to move soil in any quantity unless it is to relieve uniform flatness by creating undulations. An artificial mound must often be raised for a and it can be an economy to plan this in combination with a pool: the excavation for one making the elevation for the other.
On a site where the main garden falls away from the house a primary task could be to make a terrace against the house for which purpose the ground requires building up. The fall of a site can be broken at any point by raising a low wall of stone or brick, moving some soil to the higher level at the same time, and interrupting the wall with a couple of steps. Gardens which slope towards the house clearly present drainage problems and for that reason do not often occur. But if the nature of the site demands such an arrangement, strong banking will be needed with seep-holes through which surplus water can flow to drains linked with the domestic system.
For the lawn a level site is generally preferred, though a slight slope will assist drainage and lawn management. Some soil movement is generally necessary, and a cardinal rule is to preserve the valuable top soil which during excavation may get buried and replaced by less fertile, less friable subsoil. So shovel away as much top soil as is practicable from the area of soil movement, and keep it heaped nearby.
A slope can be levelled in three ways: 1, by adopting the lowest level and removing all soil above this; 2, by adopting the highest level and importing soil; 3, by choosing the intermediate level and removing high ground to fill low ground. Unless dramatic changes in level are required, the third alternative is the one requiring least effort and soil upset.
Now here is one way to level a site. Cultivate the ground roughly and move soil (with the precaution of reserving top soil that might get buried) until the site is roughly level by eye. Final adjustments are made with the aid of pegs, a mallet, a plank about 6 feet long and a spirit level. At a central spot in the area being levelled knock in a peg until it is flush with the ground. Knock in another peg the same distance from the first one as the length of the plank, and adjust it until the plank spanning the two pegs is level according to the spirit level placed on top. The second peg may then be proud of the ground or slightly sunk, so soil must be added or removed accordingly. Proceed in this way across the site moving soil with a rake. Finally replace any reserved top soil and distribute evenly.
While still at the early design and soil moving stage, the gardener is strongly advised to investigate whether artificial drainage is required. Free percolation of excess rainwater from the region of plant roots is a prerequisite of healthy growth. A light sandy soil will have no problems in this respect: indeed it may require the addition of water-holding. But even a light surface soil can have its drainage impeded by an impervious lower layer. A heavy clay soil will inevitably be slow to drain, and the gardener must judge by studying his soil after rain If puddles remain on the surface and constitute a drainage problem.
Be resolute and put in drainage channels at an early stage. No one will deny that it is hard work, but it may make the difference between pleasure and dismay in future gardening activities. To conduct water there must be a gradient. If the garden slopes, then take advantage of this to run channels to a ditch or ‘soakaway’ at the lowest point. On a level site, the channels themselves must cut more deeply into the ground as they cross the site to the chosen outflow point. Remember that standing water can be useful in the right place: a low-lying area can make an excellent bog garden.
Otherwise drainage water should be discharged into an existing ditch or into a rubble-filled soak-away which is dug as deeply as possible at the lowest point. Agricultural land drains are the most permanent, laid end to end in a narrow trench about 2 feet deep and surrounded with 3 inches of clinker or rubble. The alternative is to dig a similar trench and pack it with 9 inch depth of graded rubble in place of pipe drains. A single drain across the site is rarely sufficient, and a herring-bone pattern of branches, say 15 feet apart, falling to meet the main drain should ensure adequate drainage on the most difficult land.