Poor drainage can ruin a new garden bed even before you have a chance to plant. Heavily compacted soil or soil that consists mainly of clay are the two main causes of drainage issues. If you're unsure whether poor drainage is a concern in yard, you will first need to diagnose the problem. Then, you can take the necessary steps to rectify ti issue.
Diagnose the Problem
Before you break ground for the new garden, check out the drainage. Severe drainage problems are easy to diagnose because the ground resembles a soggy swamp for several hours, or even days, after a rain storm.
For less obvious problems, start by digging an exploratory hole in the proposed garden site. You want to dig about 1 foot deep, since that is how far most plant roots tend to penetrate. Fill the hole with water and time it to see how long it takes to drain. If it takes more than a couple of hours for the water to drain completely, you have a drainage problem at the site that may affect plant growth.
Check Your Soil Type
Clay soil is usually the culprit. You can check your basic soil make-up with a quick test. Scoop up a handful of soil and squeeze it tightly into a ball. Then, drop it from a few inches above the ground. If it completely shatters, you are probably okay, but your soil has too much clay in it if it retains much of it's ball form.
The best solution for poor drainage is a combination of added drainage and soil management. French drains work well for garden areas, since they are buried beside the garden beds. To create a French drain, a trench is dug around the garden site and it is filled with gravel. The trench slopes away from the site, so water will flow into the gravel bed and away from the soil.
Buried drain tiles are another option. These perforated pipes are buried around or beneath the garden site. Water trickles into the pipes and is routed away.
Change Your Soil
The next step for a successful garden without drainage issues is to remedy the clay soil. You can do this by incorporating organic matter into the existing soil. Simply spread 4 to 6-inches of compost over the ground, and then till it into the top 10 to 12-inches of soil.
For areas with extremely bad drainage or poor soil quality, you may want to build a raised garden bed instead. Building a frame and filling it with 6- to 12-inches of good, well draining soil can provide a quick remedy to a drainage problem.