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.
blog.anniesannuals.com 
The Double White is a great for cut flowers November through January. Cut flowers, plural. It makes so many!
Btw, Don Mahoney, curator of the San Francisco Botanical Garden, grows his tree dahlias under deciduous fruit trees. He said he cuts them back during the summer and lets them go when the fruit tree leaves start to drop. When the fruit trees are dormant, the dahlias are flowering, and the woody structure of the tree contains the tall dahlia shoots so they don't blow over.
Great idea doing a blog. I look forward to the interaction!
My introduction to Annie's was about a year and a half ago. I saw this interesting plant, Solanum Pyrachanthum, the porcupine tomato plant. I bought two of them at Harmony in Sebastopol. The next year, I bought two more and my son, one. I am a teacher and rotate two of them in my classroom: generally, one week in class and one outside. Of course, you gotta take them indoors when the temperature drops to 34 or below. I found that just above freezing makes them wilt and freezing kill them off. None have fruited so far. Now, I am determined to take a pilgrimage to Annie's the first chance I get, as your website came up on a random search to study the plant a bit. Although it is called a perennial, it doesn't die back if kept from getting too cold. It makes an interesting house plant if its needs for sun and warmth are attended to. With care, it is a super hardy plant. You just have to listen and watch.Cheers, Ray Teurfs
I am a bit confused – I though Dahlias died off in the winter months but someone mentioned they cut the flowers from November to January – do these plants die off? I want to plant some to cover an unsightly fence!
Lisa,
A quick and simple reply, you can find more detail on the web if you’re interested further;
The discussion above is about tree dahlias, which grow vigorously in the winter here in California, and flower in late winter and early spring. You may be thinking of the smaller dahlias which flower in late summer, and do die fully to the ground in winter. All dahlias come from Central America I believe,, and are frost tender.
Stephen