From the ArcaMax Publishing, Gardening Newsletter:
http://www.arcamax.com/news/gardening/s-156672-755524
Question: What is the best way to stake delphiniums? Would
grow-through rings around the entire plant work, or should I plan on a
bamboo or other tall stake for each flower stalk?
Answer: There are a number of different methods to support the tall
flower stalks, and it's really a matter of personal preference. If
your plants are growing in a windy location, I'd probably support each
flower stalk individually. You can use bamboo stakes or purchase
special plant supports. If they are in a sheltered location, you might
be fine with support hoops. Another method is to surround the plant
with 3 or 4 bamboo poles or stakes, and wind string around the
perimeter, creating your own "hoop."