Homes do not always come with ideal landscape conditions that result in the easy planting and creation of a good lawn and garden setting. It is most likely that most level of construction will be needed to insure the quality and life of the gardens you wish to plant and the terraces you wish to build.
Grading of the soil is the most common problem in any landscape. Grading refers to the creation of a slope (or slopes) into your property. Slopes are important as they allow for the proper drainage of water, beautify the aspect of the house and make for easier maintenance. Grading is necessary whether you are trying to create a lawn or garden terrace. Any artificial features, like garden fountain, should be built around the grading, and not vice versa.
When you begin the construction of a home, this is the ideal time to consider proper grading for your landscape. It is a simple matter to ask for a few additional inches between the entrance level and the ground level. These few inches ensure the easy development of a grade away from the house wall improving the overall appearance and allowing for a dry basement.
Rough Grading and Drainage
The first step in construction for a garden or terrace is rough grading. The condition of the ground will determine the extent of the grading needed. The desired ground levels and the attention that must be given to extreme slopes is a factor as well. Grading should adhere closely to the natural contour of the setting, since this cuts expense considerably. The first step in grading is separating and stripping the topsoil from the areas in which the level is to be changed. Even if the grading is for construction of a stone or concrete terrace, you should still save the topsoil.
The top soil can be spread in areas which are thin, or used for a flower garden, saving you a good deal of money. Once the topsoil is stripped, the subsoil can be graded to the contours desired; leaving sufficient space for adding the topsoil you have already removed. For a lawn, a gentle slope is best, with a minimum of 6 inches in slope for every 100 feet in lawn. This same measurement can be effectively applied to stone terraces as well, to prevent the development of pools of water in rainy weather.
Subsoil Drainage for Lawns and Gardens
Where the subsoil is thick or clay-like, a drainage system needs to be added for a healthy lawn. Even in sandy soil, it is a good idea to use subsoil drainage, to allow for quick and even distribution of moisture throughout the lawn or garden area. The first problem in drainage is to find an area to receive the flow. If you are on low ground, on to which water from higher areas flows, this run-off area becomes more important.
On high ground, an underground pipe that goes out and over a slope will be enough. If you are building your own drainage run-off, a dry well may be the easiest solution. This is a pit, 4 to 6 feet in depth and diameter that is filled with rubble and rock. Be sure to make sure that area is well marked, so that you know where it is if water starts to back up on your lawn. Subsoil drainage is best accomplished by the use of tile lines.
Lay the semi-circular lines of tile into the topsoil, about 1½ to 2 feet deep, in lines from 2 to 4 feet apart. These lines should be covered with a foot of cinder or crushed stone, and then soil can be replaced. The minimum effective grade for tile lines is 3 inches for every 100 feet in length. When backfilling, be sure to put all the subsoil you have removed back in and tamp it down. Any mound left after replacing the topsoil will disappear after the first winter.
Measuring Your Grading
A grade level is a smart investment to use when grading a landscape, as it is hard enough for a professional to measure grades by eye. This grade level can be something as simple as a piece of twine that is pulled tight between two sticks imbedded in the ground. After the rough work is done, level the area with a long board, dragging the straight edge along the ground to ensure your accuracy.
Grading for Terraces
When leveling an area for a terrace you do not need to insert subsoil drainage. Remember to save the topsoil. When constructing a terrace, it is a good idea to tamp the soil, and even to pour a quantity of gravel cinder or crushed rock to make a base. Terraces require a level area as a rule, but the grade sloping away from the house should be maintained.