Published on 05/13/99

Drainage Problems in the Landscape

Many times we get excited about planting new shrubs and flowers in the landscape. We buyÿ the plants, dig the hole, drop them in and sit back and admire their beauty. But six months later they sometimes turn a disappointing shade of yellow.

Problem may not be what you think

Many folks then throw out some fertilizer, thinking the plants need nitrogen. In reality, these plants may very well be suffering from a problem common in Georgia soils, called "wet feet."

ÿWet feet is the name given to a list of diseases and problems associated with poor drainage.

Our heavy clay soils tend to hold moisture well, and this often causes the roots of a plant to rot. ÿ

If the crown or major roots are affected by root rots, the entire plant can wilt and die rapidly. If only the small "feeder" roots are affected, the plant may decline slowly and just look sickly and unproductive.

Sick or damaged roots may be present only on part of a plant's root system, resulting in a one-sided appearance of yellow, stunted leaves.


PREVENTING "WET FEET" IS EASIER THAN TREATING IT Yellowing plants may not need nitrogen, but less water. Provide good drainage for your plants by building raised beds that allow water to drain quickly.

An ounce of prevention

Most root disorders can be prevented by providing good soil drainage. Follow these simple tips to keep your plants healthy and beautiful well beyond those first six months.

ÿGood planning in the design of beds and lawn areas can prevent surface drainage problems.

Slope beds and lawns so water runs away from the house.

ÿLow areas sometimes cause problems because they can't easily be graded to provide for adequate surface drainage. In such cases, you may need to construct drainage channels or French drains.

ÿRemember to take into account water coming off of roofs as well. Take care that gutter downspouts drain away from plants and don't pool water.

ÿProvide internal drainage by using raised beds (particularly for annuals and tender perennials).

ÿAmending planting beds with 3 to 5 inches of a good topsoil or compost will help improve drainage. Using less organic matter than this won't provide enough soil structure change to make a difference.

ÿDon't place soil amendments directly in the planting hole. When you use potted plants, till or spade the amendments into the entire bed. Dig single planting holes at least twice the width of the root ball. Make the sides of the hole rough and jagged.

Check drainage conditions first by filling the hole with water. If water drains in 24 hours, you can assume there is enough drainage. If water stands in the hole, take corrective measures or use only plants tolerant of poorly drained sites.

ÿWhen planting, never place a plant deeper than the top of the root ball. Remember that the soilÿ may settle some if you dig too deep and have to backfill.

ÿFinally, avoid overwatering. Most plants need about 1 inch of water per week. Any more than this may cause root problems. Water plants near the drip line of their foliage.

Bob Westerfield is a University of Georgia Cooperative Extension consumer horticulturist with the College of Agricultural and Environmental Sciences.