Shopping for dahlias

Although I ordered a dozen dahlia tubers in January — the earlier you order, the better the selection — I’m thinking of choosing a few more. Unfortunately, we weren’t able to save many tubers from last year’s plants, but this failing has an upside: A fresh start for this year and the chance to grow new-to-me varieties.

My colour choices are eclectic, but I do focus on varieties that grow about 48 inches (1.2 m) tall. These have long, sturdy stems for cutting, which is my main reason for growing dahlias. The small, symmetrical pompom and ball forms are cute, but the waterlily and decorative forms often have the most interesting shades and bicolours, making them difficult for me to resist. They’re the focal point in mixed bouquets or striking enough to go solo in a small vase. I also love the drama of the big dinner plate forms with blooms that can reach eight inches (20 cm) across, but I find these are usually less productive and easily damaged by rain and wind.

Dahlias can be grown anywhere there is good soil and plenty of sunshine. Short varieties work well in containers; tall ones can anchor the back of perennial border. I grow mine in raised beds dedicated to other flowers for the house (tall annuals), along with tomatoes, peppers and herbs.

Where to buy dahlias

Like other bulbs, tubers, corms and rhizomes, dahlias ship well, and several companies in Canada offer many delectable choices. Dahlias are usually shipped in April, so my second order will need to be sent in soon. In fact, several varieties are already sold out on the sites listed below. If you want to expand your dahlia collection, make a note in your gardening journal (you have one, right?) to order early next year. Browsing photos of gorgeous dahlias online is a terrific way to spend a snowy day, and helps to make spring seem that much closer.

• Botanus (botanus.com)
• Creekside Growers (creeksidegrowers.ca)
• Ferncliff Gardens (ferncliffgardens.com)
• FGL Dahlias (fgldahlias.com)
• Flower Bulbs R Us (flowerbulbsrus.com)
• Oakridge Dahlias (oakridgedahlias.ca)
• Phoenix Perennials (phoenixperennials.com)
• Production St-Anicet (productionstanicet.com)
• Stone Meadow Gardens (stonemeadowgardens.ca)
• Veseys Seeds (veseys.com)

Some garden centres, grocery stores and hardware stores also sell dahlia tubers, packaged in net bags with a bit of dry peat moss or wood shavings.Try to push aside some of the packing material so you can assess the condition of the tuber. Look for plump tubers with some weight; skip those that are shrivelled and dried out. At this time of year, you may see a short shoot or two emerging, and that’s fine.

Planting dahlia tubers

Whether you receive your tubers in the mail or from a store, store them in a dark, cool (not freezing) spot until ready to plant. Open sealed packing boxes or plastic bags to let air circulate.

Where I garden (Zone 6 in Canada), there are two ways start tubers:

1. When soil temperature is about 15° C (59°F) and the threat of frost has passed, dig a hole 12 inches (30 cm) deep and wide. Fill the bottom six inches (15 cm) with soil amended with compost or other organic matter and nestle the tuber on its side on top of the amended soil with the eye or growing tip pointing upward. Add the stake now to save yourself the grief of stabbing the tuber when you try to stake it later in the season. Cover the tuber with two inches (5 cm) of soil and water it in. When shoots emerge, add another shallow layer of soil and repeat until the hole is filled. Avoid overwatering at this stage—tubers rot easily. I usually don’t water again until shoots are four to six inches (10 to15 cm) tall and the hole is filled in. Plants usually begin to bloom in August.
2. For earlier flowers, start tubers indoors in mid-April in plastic grow pots with moist potting soil. Have just the tip with the eye (a white or pinkish bump) peek above soil level. Set the pots under grow lights or in a greenhouse and don’t water again until shoots are visible. Plant outside once conditions are right.

PDF download of dahlia article

To learn more about dahlias, including growing, storing and maintenance tips, consult issue No. 3 (Fall 2010) of Garden Making, pages 22 to 28. A PDF download of the entire issue is available for $5, or you can buy a digital version of the 7-page article, “Dazzled by Dahlias”, for only $0.99.

More on Garden Making about dahlias

• What to do when stored dahlia tubers sprout early
• How to divide and store dahlia tubers
• When and how to store dahlias and cannas