This is the first year I’m really branching out into more than just edibles, and trying to grow flowers as well. I’m hampered by the fact that I’m a relative novice in this area, and that between me and my mother, we’re allergic to a lot.
Luckily, besides the salvia we both love and the nasturtiums which are flowering and will most likely continue to flower until kingdom come- neither of us are allergic to dahlias.
I love them, but have always been somewhat intimidated, and have always worried that San Francisco’s alarming and capricious climate would make growing a difficult flower even more of an ordeal.
Turns out most of what I thought I knew about Dahlias was dead wrong!

Turns out all the hoops you have to jump through to grow them well in other climates don’t really apply here- because the original dahlia that would be cultivated in Europe into the myriad of forms we have now- is native to Mexico.
Part of the reason you have to carefully dig up the tubers and make sure they don’t have diseases or galls, and carefully protect your baby plants from frost is because they prefer a warmer climate with no snow or frost.
San Francisco can provide that in spades. I ordered only a few tubers, three in total, and as seen above they were ugly little things. Luckily the company I ordered them from was reputable and sent good instructions, which I mostly followed.
I say mostly because it turns out the dahlia is San Francisco’s official flower- since 1926, and the Dahlia society of California here in the city has been going strong since 1917. Turns out they grow like weeds here- and I’m chuffed as chips at that fact.

Now, I didn’t at the time have a bed properly prepared for the dahlias, mostly because I’d heard a lot of dire things about the soil needing to not be too rich and the dangers of any sort of fertilizer or compost, but also if it’s too depleted it wont grow, but also if it drained too quickly they wouldn’t grow- BUT they can rot if they get water logged…
So I figured I needed to mix a soil myself for these little princesses, though frankly, from what I’ve been reading- I may have gone overboard, and I most likely could have just chucked them in any old bed.
I had some depleted top soil I used to use for carrots, and I added some fox farm ocean forest which is a richer soil, quite a bit of coconut coir for moisture retention, and a good dash of perlite for extra drainage.
And then- I watered it well (but not too well!) and waited. Dahlias sprout from tubers in approximately 3-5 weeks after planting, depending on local conditions. So I waited. and waited.
It was exactly 5 weeks after I planted them, to the day, on April 18th, 2022- my patience was rewarded.

When I first saw this little sprout I made an inarticulate noise that only dogs could hear, and then screeched so loud I’m sure some of the neighbors thought I was being murdered.
Er… sorry Mrs. Liu.

This is what my little pot of dahlias looks like today, on May 1st.
Now I am well aware of the rules that state that you can’t have more than one dahlia to a pot- but that’s a rule I’m willing to break considering the relative size of the tubers, and the specific varieties I bought. It’s most certainly not a rule to break if you’re planting older and bigger tubers, or the really large varieties, but in my case I should (fingers crossed) be fine this year. Next year most likely I’ll want to spread the love a bit.
These are the only dahlias I’m growing from tuber- but I’ve started several from seed and look forward to popping those in around the garden. From what I’ve read, while growing dahlias from seed means essentially a random chance of color, type, size and shape- they tend to be a ton less fussy about growing conditions.
And who knows, if a particularly nice dahlia grows from seed and I can save the tuber(s) after a few years, maybe one day I’ll get to have a named variety of my own in the San Francisco Dahlia gardens!
Hey, a hominid can dream!
WHAT?! I had NO idea that dahlia is the Official Flower of San Francisco. I was not aware that San Francisco had an Official Flower, particularly for so long. I have been trying to get an Official Flower for Los Gatos for a few years. I would expect dahlias to perform better here where the climate is warmer. However, they perform very well in cool places like Portland also. To me, they actually look happier in Portland than they do here.
I feel like there’s a middle ground between places like England and New England where it’s all wet and cold and snowy so you have to baby the F out of them and Mexico where they are at their peak- and Portland having warmer summers but shittier winters and SF having cooler summers but much milder winters are somewhere in the middle ground. Makes sense that they’d do well there too. As far as a Official flower for Los Gatos- what about the native https://en.wikipedia.org/wiki/Salvia_columbariae ?
The favored Official Town Flower for Los Gatos is Typha latifolia, cat tail.