7 Steps to Planting Delphinium Seeds

What You'll Need
Cold Frame Greenhouse

Delphinium seeds, when fully grown, provide a beautifully colorful accent to a garden. Being a perennial, they will return year after year if planted correctly. It is possible to sow from either seed or cuttings to add a touch of blue to your garden or window box. Delphiniums can also be grown in some other striking colors including deep purple and green. 


Step 1- Preparing the Ground

If seeding directly, you will need to have nutritionally rich soil. If the soil quality in your area is poor or heavy, it can be improved by adding rotted manure or compost. This should be thoroughly dug into existing soil. If the soil is strongly acidic, adding lime should help. Delphiniums like soil to be well drained but once they are established, they tend to do quite well in various soil types. 

Step 2- Watch the Calendar

If sowing seeds, the process needs to be started in the early spring, March or April are recommended. If cuttings are being used, they can be put out in June or July. Delphiniums are relatively easy to grow, so seedlings or cuttings will most likely produce some beautiful results. 

Step 3- Location

The choice of location for delphiniums needs some careful thought. These perennials love plenty of sunlight, so open areas are highly recommended. However, delphiniums do not like strong winds. If this is a problem in your particular location, delphiniums will need protection of some kind. A fence or small wall should be sufficient. Delphiniums may also need to be staked if the area is largely open. 

Step 4- Pots

If planting the Delphiniums seeds in pots, try using some fine gravel or grit in the soil. This helps with the even watering of the seeds and also helps to keep the surface moist while preventing the necks of the seedlings from rotting. If growing more than one type of flower, be sure to label the pots carefully. 

Step 5- Pot Placement

Once planted, the pots can be placed outside. To speed the growth process, try placing them in a greenhouse for a week or two. This also reduces the need for pesticides and will help protect them from insects. 

Step 6- Growing Pains

The seedlings should soon start to show themselves. When they are large enough to handle, they should be transferred to individual pots. To remove them, gently work the seedling from the soil by hand working beneath the plant. Do not pull by the stem as it could easily be damaged. 

Step 7– Light Exposure to the Elements

If started indoors, it is best to expose the seedlings to the outside elements on a gradual basis. Placing them in a cold frame greenhouse is the most recommended method but keeping them indoors with short periods spent in the garden is fine as well. Simply increase the number of days that the seedlings are exposed to the outside air until they are ready for planting. 


Delphiniums enjoy space, so avoid overcrowding them. It might be best to keep children away from the delphiniums once they bloom. They are toxic if eaten and are especially dangerous to cattle.