3 Dahlia Tips From My First 2 Seasons

Dahlias are incredible flowers. Intricately symmetrical, succulent petals. Gorgeous colors. So many shapes and sizes. And because it’s pretty easy to dig up and preserve the roots even in cold climates, they can be grown almost anywhere. I’m getting ready to wrap up my second season growing dahlias, and have been thinking about what I’ve learned, other than how much I love them. :) They do take more effort than some other plants, but in my experience they’re definitely worth it! Here are three of my takeaways so far.

A bucket of freshly picked dahlias.

1. There’s a wide range of productivity in the number of blooms you get per plant over the course of the season. In a small space, it’s important to prioritize varieties that are prolific and reliable bloomers. I’m keeping this in mind now when I research any new ones to try, vs. mostly just choosing based on how gorgeous it is (because aren't they all?)

A few varieties that are keepers for me so far are Rose Toscano, Ivanetti, and Blizzard. One pretty pink one called Rock Run Ashley is on my nix-it list… she doesn’t bloom as much, sometimes faces downward, and sometimes blooms a pale yellow or half yellow/half pink. Coincidentally, some of the most floriferous ones also seem to last longest in the vase too. There are several other varieties that I just had one or two of this year, so I’m going to give them another year before I make the final call.

A Cafe au Lait dahlia that looks almost hand-painted.

2. Fertilizing the plants with diluted fish emulsion and blackstrap molasses was super helpful. This past summer, my plants looked great for the first several weeks, until they started getting weird and a little stunted, with yellowing leaves. So I started spraying them once a week with diluted liquid fish/kelp emulsion (it smells bad, but it's easy to find at garden centers) and blackstrap molasses (it's supposed to help fend off pests and encourage beneficial bacteria).

I mixed 2 tablespoons of fish and 1 of molasses per gallon of water, in a handheld pump sprayer. Within a couple of treatments they started putting on vigorous, healthy green growth and recovered beautifully. Next year I want to start the fertilizing as soon as the first sets of leaves are out, and see what the results are.

An armful of Rose Toscano and Rock Run Ashley dahlias.

3. Digging up the roots - “tubers” as they’re called - and dividing isn’t as scary as it seems. At least it was scary to me! I did wreck some viable tubers, but I definitely ended up with more than I started with. Unless you were to take a sledgehammer to the clump, it’s easy to at least triple your original stock, if not quintuple.

I actually really enjoyed the process once I got going….it’s kind of like a reverse puzzle to take apart the clump and see how many new plants you scored. And the number grows exponentially with each year! I can see how someone might find themselves eventually growing hundreds. Or thousands. I’m only at 65 this year, but I’m so excited to see the underground harvest in a few weeks! It's like Christmas morning for gardeners, as Erin Benzakein at Floret says.

Do you have any dahlia tips? If you don’t grow them now, are you thinking of giving them a try next year?