Summary: Discover how to plant delphinium including sun and soil needs as well as spacing, planting, and care.
Delphinium blooms in late spring and early summer and prefers moist cool summers. Delphiniums struggle in hot dry climates. Delphinium are available in different sizes including dwarf (less than 2 feet tall) and tall (6 feet tall), and come in a variety of colors including yellow, white, red, and blue.
Sun and Soil
Delphiniums are sun worshippers and should be planted in the part of the garden that has full sun and where the plant can be shielded from wind. Delphiniums grown into tall, top-heavy plants and strong wind can cause damage. The perfect soil for planting Delphiniums is well nourished and has proper drainage.
Delphiniums should be planted in the spring. Each Delphinium plant should be spaced a minimum of one foot to three feet apart. Begin the planting by tilling the first twelve inches of the top soil with a garden fork to loosen it. Prepare the soil by spreading a layer three to four inches deep of compost or fertilized planting soil and mix it into the soil.
Use a gardening spade to dig a hole that is twice the diameter of the pot your new Delphinium plant came in. Carefully remove the plant from the pot. There are a couple of ways to get the plant out of the pot without causing damage. First, assuming the pot is plastic; gently squeeze the pot together between your palms to loosen the soil. Rotate the pot a half turn and squeeze again. Note: squeezing too hard can crack the plastic pot. The second method to remove the plant from the pot is to gently insert kitchen knife or small spade into the inside of the pot and run the tool around the inside of the pot until the soil is loosened.
Gently pull the plant out without tearing or damaging the root ball. This will help avoid damage and shock. Never remove the plant from the pot until you are ready to plant. Exposing roots to the air will damage or possibly kill the plant. Place the Delphinium plant in the hole so the top of the root ball is level with the top soil. Fill in around the plant with soil and gently pat with your hands. Water the Delphinium thoroughly. Throughout the life of the Delphinium plant keep it fertilized and never let it get dry.