The best chance of having delphiniums that don’t blow over is to plant them on the east side of the house or garage where they get good early day sun and where they are protected from the west wind. Next is to put in varieties that are not so tall and top-heavy. Here are a few varieties that fit that bill.
Delphinium grandiflorum is a short variety with bigger than larkspur flowers. There are several varieties which do well here, and though they may be short-lived, are great as bedding plants, and since they self-sow are also good for naturalizing. ‘Blue Elf’ is my favorite with gentian blue flowers on stems only 12”-18” high; also good is ‘Blue Mirror’ which grows to 20” with marine blue flowers; ‘Blue Butterfly’ grows to 18”-24”. They can be grown up to 8500’-10,000’.
Another sturdy stander is Delphinium belladonna. I know the variety ‘Bellamosum’ which is 3’-4’ tall with dark gentian blue flowers on a more open inflorescence, the flowers being less crowded and less heavy than the tall hybrids. It thrives in my xeriscape in a little shade.
Also good is Delphinium sp. ‘Blue Springs’ which only grows to 2’-3’ high and 1 ½’-2’ wide. It has maple-like leaves and thick stalks with marine blue flowers and requires less water than most varieties.
‘Magic Fountains’ sounds good at 24”-30” with blue and purple flowers. The grandmother of many modern hybrids, D. elatum grows to 4’-6’ with blue flowers and may stand up better than the hybrids. I will find out this year since I grew it from seed, which was not difficult. Other good bets would be D. tatsienense with deep blue flowers to only 12”-18”, D. brunonianum-10”-24”, and D. oxysepalum.
Also worth growing are the annual delphiniums or larkspurs, Consolida ambigua and Consolida regalis. The latter has two very nice varieties ‘Blue Cloud’ and ‘White Cloud’ growing to 2’-2 ½’ with densely branched forms and very long and showy blooming.
All delphiniums make good cut flowers, are poisonous to humans and animals and are one of the few truly deer-proof plants.