Gardens on slopes often face drainage problems. Instead of draining off the garden into the grass and soil around it, water in gardens with drainage problems is trapped, and this usually results in puddles in the garden. Too much water around your crop can cause problems, such as root rot. To avoid this, you should build a drainage system into your garden. The system will draw the excess water away from the crop, which will hopefully result in a high and healthy yield.
Dig out the top 15 cm (6 inches) of your garden and replace it with garden soil. Drainage problems can occur because of poor soil. Soil that is laden with clay and sand will often trap the liquid, instead of allowing it to drain. Replacing the previous soil with loose garden soil may assist in drainage.
Dig trenches in your garden if the drainage problem isn't severe and only results in a few small puddles. Dig trenches that are about 30 cm (1 foot) wide and 7.5 to 10 cm (3 to 4 inches) deep in the soil with a shovel. Dig them in the direction of the slope, so the force of the water moving down the slope causes it to enter the trenches and drain from the garden.
Dig a large hole at the bottom of the slope if the drainage problem is more severe and results in a number of large puddles on your garden's surface. The hole size depends on the size of your garden. For expansive gardens, plan on digging a hole that is about 1.8 m (6 feet) wide and 60 to 90 cm (2 to 3 feet) deep. Fill the hole with gravel, stones or broken bricks and then cover it with about 30 cm (1 foot) of garden soil. The water will collect in this hole, called a soakaway, instead of bogging down your soil.
If trenches and the soakaway will not resolve your drainage problems, install pipes under the garden. This can be challenging, as you have to work around your water table and various other challenges, such as gas pipes and electrical cables. Hire a professional to install the pipes if you decide on this course.