Picking the Site

• Delphiniums grow tall on delicate fleshy stems. choose a spot out of the wind for your delphiniums. You can also grow delphiniums in patio pots and planters in protected areas. The plants grow best in full sun but tolerate some shade. Loamy or sandy soil creates an ideal growing environment as long as the area drains well. Plan to space the plants one to three feet apart at planting time. Space shorter varieties one to two feet apart and taller varieties two to three feet apart.
  
  

Planting Delphiniums

• Plant delphiniums in spring. The plants are perennials, so they come back each year. Spread 2 to 4 inches of compost over the area to prepare the soil before planting. Dig the compost into the top 12 inches of soil. The compost adds nutrients to the area to get your delphiniums off to a vigorous start. Dig the holes slightly larger and as deep as the nursery pots. Plant the delphiniums the same depth in the soil as they were in their original pots.
  
  

Mulching and Watering

• Keep the soil moist around your delphiniums during hot dry weather. Soak the soil when the top inch starts to dry out. Around the plants, spread a layer of compost 2 inches deep and cover it with a 2-inch layer of wood chips, sawdust, leaf mold or other organic mulch material. The mulch layer keeps moisture from evaporating, keeps the soil cool in hot weather and leaches additional nutrients into the soil. Spread the mulch layer in spring and replenish it each year as the material breaks down.
  
  

Seasonal Care

• Cut the flower stalks at the soil line after they die back naturally. Remove the foliage in late fall or early winter after the first frosts kill the leaves. Spread the mulch layer over the roots to insulate them during cold winter months. Pull the mulch back in spring to allow new shoots to emerge. Divide delphiniums every three years to keep the plants from getting overcrowded. Wait until new shoots begin to emerge in spring before dividing delphiniums.