Growing Delphinium from Seed in the Home Garden
When sowing delphinium seed you should start by using a disease free seed sowing mix if possible (to avoid "damping off" to which delphiniums are particularly susceptible).
Cover the seed lightly. In the past we have recommended to commercial seed growers, the use of a trichoderma fungus as in our experience it has totally eliminated damping off problems, both above and below the surface. As a consequence our germination percentages are as high as possible. All viable seed grow. You may also wish to take advantage of this product.
One of our customers, Greg Kosmala from Oregon writes about using Rootshield:
The Trade name for the biological fungicide that I used is called "Rootshield" and I got it from Territorial Seed Co. in Cottage Grove Oregon. Manufactued by Bio Works, Inc. in Geneva NY. I found out about it through a greenhouse class I was taking. It seemed to work very well and I did not seem to have any damping off issues after I started using it. I used it as a drench to wet the soil mix before planting the seeds in the cells firstly, then in the water to irrigate the seedlings as they appeared. The label does say " best used in the season purchased" so looks like you have to purchase it yearly as you mentioned.
Keep in an airy (not draughty), light* place. Water only enough to keep the surface from drying out. It is very important not to overwater or the seed, or seedlings will quickly rot.
It is best to chill seed for a week before sowing (stick them in the fridge).Germina tion for most species is best between 18 and 24ºC (65-75ºF) Do not allow temperatures to exceed 80ºF (26ºC). Once germinated the seedlings will grow on perfectly happily in much cooler temperatures.
If you are not using trichoderma fungus then watering the seed in with "terrazole"(etrid iazole) or similar fungicide can be beneficial in helping to prevent disease problems (pithium and phytophthera sp). Give a further treatment when most of the seedlings have emerged after about 10 days to help to reduce damping off when conditions favour the disease.
For germinating small quantities of delphinium seed, try the following:
Find a small, flat plastic container (such as the plastic tray that cheese wedges come in) and make three or four small holes in the base. Half fill with damp, sterile seed sowing mix. Sprinkle the delph seed on the surface and cover lightly with more potting mix. Put the lid on. Put this in a plastic bag and place in the fridge for 14 days. Remove from the fridge, take off the plastic bag and the lid and place on a shallow saucer in a warm, sunny or very light place. Make sure there is just a little water in the saucer each morning. Your delphinium seedlings will respond very well. Pot them each individually into a small pot when the first true leaves appear.
Or you can try this method from Pamela of Backwoods Cottage, California. She uses coffee filters and a ziplock bag.
Always buy your seed from a trusted source and always, but always, store it in the fridge. Delphinium seed goes off very quickly at room temperature.
Need to know more about growing from seed? Check out this excellent tutorial Gardening 101 at the Garden Helper site.
Want help on seed raising in Russian? download this file (PDF - 266kb).