Good drainage is essential in a garden. Not only for practical reasons — no one wants permanent puddles outside the back door — but also for the benefit of plants, as they may suffer in poorly drained areas.

Poor drainage may be caused by soil compaction; a common problem around new homes. Impermeable clay subsoil or a naturally high water table may be another reason. Determine what type of soil you have, and also make a note of low spots and wet areas.

For more information about how to determine what type of soil you have, refer to Resources.


Grading is the movement of soil. When dealing with garden design, grading provides drainage for surface water, areas for play, and paths for movement within the garden. Always consider the effects on drainage when grading for any purpose. After drainage, terracing to increase the amount of flat land is the most common reason to undertake grading activities.

While it is important for the homeowner to plan and visualize the results of potential grading changes, it is best to consult with professionals for significant grading projects. Contact your local planning department to learn about the possible need for permits and, before any work is done, call Underground Service Alert.

Level or Sloped

Few properties are perfectly level. The slope (steepness) may be only a few inches from end to end or so severe that it’s difficult to walk up and down the property. To make the most of your property, ask yourself the following questions:

  • Does your property have a slope? The existing slope will determine what actions should be taken. Ground covers may be the answer for long, gentle slopes. Most ground covers (not grass) will probably stabilize a 1:2 ratio (1 foot of rise per 2 feet of run) to 1:3 slope. Lawn or bark mulch should not be placed on a slope with a ratio greater than 1:2 feet of run.

There are many green, water-efficient groundcover choices better suited for slopped areas than grass.
  • Do you need to create easier access to an elevated area? Steps, stairs, and ramps allow for change in elevation. Avoid the use of a one-riser step because they are often too shallow to be noticed and can cause a tripping hazard.

  • Would you like or need terracing? Railroad ties or blocks may solve the problem.

Natural stone steps blend the upper and lower gardens beautifully.
Stone steps