Growing and storing dahlias

Growing and storing dahlias is not that difficult when you know a few key secrets. Now, with the help of this blog, you can become a master dahlia gardener and enjoy the beautiful results.

For all of you who live in the Seattle area, what is the first thing that comes to mind when I say the word “Dahlia”? If you said, “It’s a restaurant,” you would be correct but I wonder if you may need more exposure to an especially beautiful flora that is grown in many yards and landscapes in the Pacific Northwest and is used to create the most elegant centerpiece.

Most people in Seattle are familiar with the dahlia plant; and those who are, often suffer with the addiction of growing and caring for them. The only 12-step program these people know in regards to their addiction is the number of feet from their door to their first dahlia! We know of people that have upwards of 30 unique specimens in their showy gardens. Should we tell them that there may be more than 50,000 varieties within 36 species?

In this blog, I want to help the beginner and dahlia addict alike. Here are my thoughts on growing and storing dahlias.

The dahlia is a superb flower to have in a garden. It is very colorful, has great presence, and the shapes may remind you of the boy next door’s haircut or a porcupine or a star. And because of its majestic presence, it becomes the star of your garden!

The dahlia does require some care when growing and storing. The biggest issue about dahlias is that they are not frost tolerant. They are tubers and the “roots” must be dug up at the end of their growing season (before the first frost.) They should be stored as you would potatoes, and then replanted after the danger of frost has past. Dahlias can also get some diseases like mildew, wilt, and mold. And sadly for those of us in the Seattle area, the dahlia is considered a delicious dessert by slugs and some insects, including aphids. It is reported that deer don’t munch on dahlias as often as they would roses, apples, etc., so that may give you some hope that growing dahlias in your garden is venture worth trying.

To plant dahlias, put in a stake that will support the variety you are planning on growing. The stake should be sturdy enough to support the plants in a strong breeze. Put the tuber in the ground a few inches deep with the eye (this looks similar to the eye of a potato) facing up. The hole should be about 6 to 8 inches deep depending on the tuber. Consider putting some bone-meal (3 Tbs. or so) deep in the hole, covered with a bit of dirt to make sure your dahlia has food. Keep tubers around 2 feet apart to give them growing room, and make sure you don’t plant shorter ones behind taller varieties.

Once the dahlia is planted, create a label with the name of the variety and display at the location. Of course, labeling each dahlia is optional (it won’t help them grow) but it will help you know how tall they will be, and gives you better ability to brag about your “Bristol Stripe” (rather than referring to it as “the pretty one over there next to the really unique one”.)

Now, dampen the soil. Then walk away. Do not water it again until you see the shoots appear; wet feet could cause root rot so don’t over water. Once the shoots appear, be vigilant for slugs. Get out the slug bait, beer traps, volcanic rock, etc. (see our article post on slug control).

As your dahlias grow taller, tie the stems to the stakes to give added supported. Tall tomato cages could be used instead of stakes. The idea is to prevent wind from knocking the plants over and bending them. Some movement is fine. As they grow, they will produce shoots with buds. If you see three buds on a branch, remove two of them so your flowers will be more magnificent. You might also want to completely remove the lower branches and keep the flowers at the top where they will be best seen.

Towards the end of the year (October or November), dig up the tubers and store them just as you would potatoes -- a cool, dark, dry place with air flow is best. Separate the tubers. Then wrap them in paper towel, place in sawdust or kitty litter, or hang in discarded stockings. The intent here is to keep them dry. If they get too wet, or can’t “breathe”, they may rot leaving you with compost material.

Finally, be sure to label you dahlia tubers (or use the marker formerly used in the garden.)

I hope you enjoy growing dahlias. I think you’ll agree…this is one addiction that has rewarding and beautiful results.

Category: Northwest Gardening