I grew some delphiniums this year. Some I got seeds from New Zealand. Others were Blue Mirror and Connecticut Yankees. I started them in January. I just had to stake a couple of them today. This has been the coolest spring on record. I imagine the summer heat will be coming soon. Usually we are hot and dry by now, but it has actually rained lately. Maybe we will get a cooler summer this year, but probably not. If they bloom next year, I will be happy.
You are right! They are expensive to buy as plants. I hope I will see some flowers on them next year. Then I will try to take some cuttings as well as sow more seeds.