Regional Gardening Reports :: National Gardening Association

In the Garden:
Pacific Northwest
May, 2001
Regional Report

Share |

This gnarled cluster of dahlia tubers is about to be divided. Each division will produce a bushy, multistemmed, 6-foot plant loaded with spectacular flowers.

Delightful Dahlias

Now that soil and air temperatures have warmed, it's time to plant dahlias. I never met a dahlia I didn't like. They come in all sizes, from dwarf plants that can be tucked away in a border to almost bush-like giants. They have a variety of bloom shapes and shades that range from white to multiple colors.

Dahlias grow from storage organs called tubers. A single tuber planted in spring will develop many new ones, radiating out like the spokes of a wheel or clustered densely around the base of the stem.

Plant for Production

Dahlias thrive in sunny beds amended with lots of organic matter. I grow the larger bush-type dahlias by digging a 12-inch-deep hole for each tuber and mixing a handful of bonemeal into the hole. Then I lay the tuber in the hole with the bud facing up, drive a 6-foot-tall stake into the hole for future support, backfill with soil, and water well. The bonemeal will provide initial nutrients for the young tubers and plants. Just before the first blossoms open, I side-dress plants with a granular 6-10-10 fertilizer to ensure continual flowering. Plants are spaced 3 feet apart to give each enough room and to encourage air circulation around the plants, which reduces disease problems.

Pinching Dahlias

Some gardeners pinch off side buds to direct growth to one flower bud per stem, which results in fewer but larger flowers. If I were growing for show, I might be tempted to pinch off buds, too, but I prefer to leave my plants alone and enjoy the multitude of slightly smaller flowers they produce all summer long.

Dahlia Care

Other than regular, deep watering and occasional deadheading, I've found dahlias to be relatively carefree plants. I like using the flowers for indoor arrangements and have discovered that earwigs like to hide between the flower petals. I once had several crawl out in the middle of a dinner party--a most inopportune moment! So now, when I cut dahlias to bring indoors, I immerse the entire flower in a bucket of water to dislodge any hitchhiking pests.

Storing Tubers in Winter

I dig tubers in October and November, even though they're hardy here, because they tend to rot if left over winter in our wet soil. I leave 6 inches of stem to serve as a handle, brush off excess soil, and store tubers in plastic mesh bags in my unheated garage. An alternative storage method I've had good luck with is simply burying the tubers in a bucket filled with vermiculite and storing in a room protected from freezing temperatures.

Making More Tubers

Tubers can be divided immediately after digging, but I prefer to store them in one big clump, dividing them in spring after the eyes (new growth points) begin to swell. By waiting until spring, I'm assured of cutting them apart in the right place, without injuring the dormant eyes. It's also easier to know which side faces up. Some of the stored tubers look plump and some look dehydrated. The plump ones will be planted first, in the choicest garden spots, followed by their wrinkled relatives, placed in an out-of-the-way garden plot, just in case they don't survive and need to be replaced midseason.

Care to share your gardening thoughts, insights, triumphs, or disappointments with your fellow gardening enthusiasts? Join the lively discussions on our FaceBook page and receive free daily tips!


Today's site banner is by nmumpton and is called "Gymnocalycium andreae"