Q.Delphinium lost all its flowers.
Greetings I purchased a awesome purple flowering Delphinium and some of the leaves are brown and coming off and all the flowers are now gone. I did use some 10-10-10 but only about a tablespoon full can you advise?
The flowers will last a limited time period. If they were in flower when you purchased, it can be hard to say how long the flower period will be.
You can cut down the spent flower stems, and your plants may send up other shoots yet this year.
These articles will help refresh you on growing these perennials.