Dahlia Culture

Dahlias require special soil, staking and water.

A sunny location with good surface and internal drainage of the soil is a must. A clay soil will grow good dahlias provided it is amended.

Dahlias are favored plants among many gardeners. However, they are limited many times by restricted garden space. Dahlias require special soil preparation, staking, watering during dry periods, disbudding and strict insect control. Gardeners who grow them successfully find them quite rewarding even though they are demanding.

Dahlias are purchased as tubers and there are many types, heights and colors. The dwarf dahlias are usually purchased as started plants in peat pots or trays.

Start preparing the soil before the April planting time arrives by spreading 3-4 inches of manure, 2-3 inches of rotted leaves and 1 inch or more of coarse sand. These materials should be spaded or plowed in as deep as possible. Dig large holes about 18 inches deep and 18-24 inches wide. Use the loose, pulverized, amended soil to fill the hole 2/3 full. Mix 1 cup of lime per hole, if your beginning soil is a red clay. The tubers should be planted four to six inches deep. Some gardeners prefer to lay them on their side.

Dahlias must be staked.

Because dahlia stems are very soft, tender and subject to breaking in strong winds or heavy rains, they must be staked. Use a 6-foot strong wooden or metal stake, sinking it 1 foot deep immediately after planting. As the new stems develop they should be loosely tied with wide cloth strips. Some gardeners prefer two stakes spaced 18 inches apart. Remember dahlias require space so allow 3 - 4 feet between plantings.

Fertilize each month…

Plan to fertilize each month after planting using 1 cup of a balanced fertilizer such as 8-8-8 or 10-10-10.

And water…

Dahlias need plenty of water. Meet their needs by thoroughly soaking the soil once each week throughout the growing season. A 3-inch mulch of leaves or other materials will reduce the need for watering plus helps with the weed problem. Inspect your dahlias regularly for insects. A weekly spraying or dusting with sevin and malathion will help avoid serious insect problems .

For more information on dahlia culture, contact your local county Extension office.