How to Fix Overwatered Clay Soil

Clay is a soil rich in the nutrients that plants need to thrive and it holds water. On the other hand, clay soil is easily overwatered, which causes compaction and eventually plant death. It is much easier to prevent overwatering of clay soils by adding lots of organic matter in the form of compost, well-rotted manure, leaf mold or peat moss. The organic matter prevents clay particles from clumping together. This clumping is what makes overwatered, soggy clay soil so hard to work with. You can fix overwatered clay soil by adding lots of organic matter and gently working it into the soil. Fixing overwatered clay soil may take weeks to complete and during that time you will need to remove and store the plants that were growing in the soil.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Shovel
• Compost or well-rotted manure
• Garden fork

1. Stay off of over-watered clay soil as much as possible to prevent further compaction of the soil. Try to stand outside the area that was overwatered as much as possible as you work with the soil.

2. Dig up and remove as many plants as possible. If left in the over-watered clay soil, the plants will suffocate. Leave large shrubs or trees in place. You will have to work carefully around the roots to prevent permanent damage.

3. Cover the clay soil with 6 to 8 inches of compost or well-rotted manure.

4. Wait 2 to 3 days to allow the clay soil to dry out slightly. The compost or well-rotted manure will soak up some of the excess moisture which will dry out the clay faster.

5. Use a garden fork to work the compost or well-rotted manure into the top 4 to 5 inches of soil.

6. Step on the tines of the garden fork (just like you would a shovel) to embed the tines as deeply into the soil as you can. Keep your foot on the garden fork and pull the handle gently (too much pressure may break the handle) back towards your body. This lifts the soil and allows the compost or well-rotted manure to penetrate into the soil.

7. Go over the soil with the garden fork 3 to 4 times to aerate the clay soil and work the compost or well-rotted manure further into the soil.

8. Wait 4 to 5 days, then repeat Steps 6 and 7.

9. Check the clay soil for dryness when you have finished working the compost or well-rotted manure into the soil. Dig a small hole, about 6 inches deep. Wait for an hour and then check the hole. If it has filled with water the clay soil is still overwatered and has become waterlogged. Repeat Steps 3 through 9 until a hole dug in the clay does not fill with water.

10. Replant removed plants when the clay soil has dried out.

Tips & Warnings

• If your amended clay soil still becomes overwatered you may either build a raised bed (at least 12 inches tall) on top of the waterlogged soil or have a drainage system (which is very expensive) installed to aid drainage.
• Do not add sand to overwatered clay soils. While it sounds like sand would improve clay soil drainage you will end up with a very large brick when the clay drys out.
• Do not use a garden tiller on overwatered clay soils. The motion of the rotors on the tiller will compact the soil making it much harder to work with.

References

• "Taylor's Master Guide to Gardening," Houghton Mifflin Company; 1994
• "The Garden Primer," Barbara Damrosch; 1988

Resources

• Wildflower Farm; Understanding your Soil
• Organic Gardening; Double Digging How-to