Is Sandy Soil Good for Dahlias?

A healthy, bright red dahlia flower

A native of Mexico, dahlia flowers (Dahlia spp.) are cultivated for their brilliantly colored, complicated blooms. While dahlias grow well in sandy soils, a few alterations to the soil can help the plant thrive even more.

Drainage

Dahlias require a well-draining, aerated soil in order to truly thrive. Clay-based soils are often too dense, while sandy soils may allow nutrients to seep out too quickly. A mix of about 50 percent native soil (sandy or otherwise) with 50 percent organic matter is usually ideal.

Watering

Since sandy soils drain quickly, dahlias grown in sandy soils can tolerate more frequent watering than those in moisture-retentive clay soils. Regardless, dahlias may suffer from root rot if watered more than three times a week.

Fertilizer

Sandy soil can be enhanced with a slow-release fertilizer such as bone meal. Apply the fertilizer at planting time and again about a month after the initial planting. Always use a low-nitrogen fertilizer with dahlias, as too much nitrogen will promote foliage growth rather than flower growth.

References

• Dahlia Barn: Dahlia Care
• Dahlias: Soil and Bed Preparation for Dahlias