It's Time to Plant Dahlias
Updated: Mar 19, 2021
March is a busy month for Northern California gardeners. The weather is getting warmer and the nurseries are full of tempting little annuals to brighten up your yard. I think February is the best time for planting those spring annuals, but March is the right time to plant tomatoes, dahlia tubers and rooted chrysanthemum cuttings. I’ll dedicate the next three posts to those topics, starting with dahlias.
Dahlias have become more and more popular every year for a while now. Flowers go in and out of fashion—maybe not as quickly as trends in clothes, but there’s a cycle just the same. Dahlias have been on an upswing, and it’s easy to see why. They’re beautiful and extremely varied in color and form, making it easy to find one you like. Don’t like red? Try a pink one. Don’t like pink? No problem, you can have white, purple, peach, bright orange, yellow, cream or salmon. Want huge flowers? You can have those, in fact you can any size bloom you want, in different forms. You can have fluffy “decorative” forms or refined looking “waterlily” forms. You can have “collarette” or “orchette” forms. You can have bicolors and blends, balls and pompoms. The variety is astonishing.
A few of the many dahlias I've grown, clockwise from top left: 'Marcia Dawn,' 'Pooh,' 'Hy Mom' and 'I'm a Hottie.'
Most gardeners start with tubers when they grow dahlias, but you can also buy plants. I’d recommend that if you’re a complete novice. But be sure to check the height information for the plant you’re considering. Dahlias vary in size almost as much as in color and form. If you’re planting at the front of a flower bed you should stick to the smaller types, but if you have a sunny spot where you can accommodate a 5’ plant, then go for a tall variety. If you’re starting with tubers, the same advice applies, because you’ll see a range of heights and you don’t want a tiny two-foot plant stuck at the back of a flower bed and overshadowed by taller plants.
If you decide to buy tubers, see what’s available at your local nursery or try an online catalog. One of the most popular dahlias you can buy is ‘Café Au Lait,’ but I don’t recommend it for beginners. It’s more finicky and like many of the largest flowered dahlias, it won’t bloom until late in the season. Try ‘Vera Cruz’ or ‘Karma Corona’ if available. If you’re buying tubers from an online source you’ll be overwhelmed with choices. ‘Pooh’ is a reliable choice, so is ‘Bahama Mama’ or ‘Mikayla Miranda.’
When you get your tuber, plant it as soon as possible, but don’t water it. That seems strange, doesn’t it? Choose a site with good sun exposure, then dig a hole 4-6” deep and lay the tuber at the bottom, horizontally. If you see any sprouts, try to have them on the top side of the tuber in the hole. Cover the tuber with dirt but don’t water it until you see sprouts coming up. If it rains a little, that’s OK, but the point is to avoid too much water if possible, so the tuber doesn’t rot. Once the sprouts are out you can start watering. I’ll post again later about fertilizing, staking and deadheading as your plants grow. There’s so much to say about dahlias that I can only cover the basics of planting in this post.
For more info, I recommend the Floret website, or the new dahlia book by Floret’s owner, Erin Benzakein. The book is called “Discovering Dahlias.” I also recommend videos by Swan Island, the website or Instagram feed of Kristen Albrecht at Santa Cruz Dahlias, and the website of Goldenrod Gardens. Those are only a few – a quick look around the internet will convince you that there’s much to learn about dahlias. But don’t get overwhelmed – just go buy one or two tubers and get started!