We Bay Area folks are blessed by the Dahlia Deities, for we not only get to grow these magnificent towers of flower, they grow here LIKE WEEDS (Have no fear, they are not invasive and do not self-sow). Those of us who grow these in our own gardens, and especially those who have plants that are visible from the street, know it is the kind of plant to draw a crowd. Passersby get a bad case of rubberneck, drivers park suddenly and hop out of their cars with cameras. It is not unheard of for total strangers to knock on your door to enquire with awe, What IS that thing?
It is Dahlia imperialis, people, and it is a whole lotta Dahlia! To at least 8 ft. tall, it can reach 20 ft. when happy. In areas with cold Winters, some gardeners include this monstrous beauty just for its foliage! The tall canes are bamboo like, with lush leaves. The flowers, though, the flowers!! Each lavender pink bloom can span up to 6” and the massive flowering panicles can be 3 ft. across – and mind you that is per stalk! Large plants can produce an abundance of flowers both alarming and astounding when you stand underneath them in full bloom and see them allll looking down at you. Wonder!
We grow TWO forms of Dahlia imperialis – the single pink form, and a fantastical double white flowering form that has all the same requirements, but with stupendous double white flowers that look like shooting stars. Not only that, but occasionally – sorry guys, not right now! – we have another very special tree Dahlia species – Dahlia tenuicaulis, which blooms early and often with dark purple-magenta flowers. And we have a FOURTH top secret tree Dahlia in the works that I cannot talk about. Actually, forget I ever said anything. OOPS.