An idea of luxury is to always
have plenty of delphiniums. They’re not reliable in hot climate, so you must
replace several of them each year. But it is gladly, not only for their
magnificent flower spikes in the garden, but also for summer bouquets. They
need extra attention, but they earn it. The most stunning ones are hybrids of
Delphinium elatum, which are tall grand often upwards of five feet. Among these
are the “Giant Pacific” series, which come in many shades and are often
bicolored each flower along the spike having the center, or bee in a
contrasting color. The vivid blue verities such as Blue skies are favorites,
but always grow a purple, too such as King Arthur, and mauve, such as Astolat.
The dwarf Blue Fountains hybrids are similar but only two feet tall.
Many delphiniums are a bit more
reliable and very beautiful in their own way. Belladonna (light blue) and
Bellamosum (dark blue) are three to five feet with an open from spike.
Connecticut Yankee is a bushy 2 ½ feet in a number of shades. Chinese delphiniums
(D. Chinese) are less than two feet and a very intense blue. Well to grow
delphinium, prefer climate with cool summers, where their stems grow tall and
strong, and where they are free from diseases that attack them diseases
aggravated by hot muggy weather. Select a sunny location if possible one
protected from the wind. Even there they will perhaps need to be staked. The
stake should reach to the point where the flower spikes starts. Give them a
very rich, alkaline soil. I dig a cupful of lime into the hole before planting,
and top areas established clumps with a cup of lime each spring. I also top
dress with a balanced granular or liquid fertilizer in spring and after the
plants bloom. You must avoid mulching around the crowns (the place where the stems
join the roots), moreover this can cause rot. Further remove all but five of
the strongest stems in each clump in the spring and cut off spent flowers after
they bloom in early summer. Then cut back the stems when you see new growth
start to appear. Most will bloom a second time in later summer, but will tall verities
the blooms from the second flowering will be shorter. Delphiniums will bloom
the first year from seed. Source: Charismatic Planet