Along Three-Mile Drive across from the Chinese Garden
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Established in 1971, the North Central Dahlia Trial Garden is one of eight official dahlia trial gardens in North America. Located along Three-Mile Drive, it is planted and maintained by the Minnesota Dahlia Society and Arboretum staff. Each year the Dahlia Society plants a new selection of hybrid dahlias which are then evaluated for growth, habit, disease, flower quality and other characteristics. Successful flowers are then recommended to the American Dahlia Society. Because it is a trial garden, visitors will only find numbers and letters on the labels — not names. Since dahlias will not survive Minnesota winters, the tubers of these beauties are dug up, cleaned and stored in a cool, dry location over the winter.
Garden Plants
The new dahlias are marked by numbers to assure the anonymity of the originator and allow for unbiased evaluation. They are judged and scored by accredited Dahlia judges, using the American Dahlia Society judging manual as a reference. Dahlias must receive a minimum score of 85 points based on form, color, stem and foliage to be released for introduction to the public.
A few named varieties of dahlias are located around the outer edges of the garden to serve as buffers and act as control plants. Additional named varieties are in the Dahlia Collection, located on the hill behind the Snyder Building.
About the Minnesota Dahlia Society
The Minnesota Dahlia Society (MDS), based in the Twin Cities area, is one of the largest dahlia societies in the United States. The MDS hosts several meetings each year, an annual Tuber Sale, an annual members’ garden tour in late August, a two-day show at the Minnesota State Fair, a show at Bachman’s Garden Center in mid-September and other events throughout the year.
Saturday mornings during the growing season, a work team from MDS tends the trial garden. New members are encouraged to join a work team to learn how to grow from experienced growers and develop friendships as well. Learn more on their website!
At-Home Gardening & Care
Moist, well-drained soils, full sun and regular fertilization are the keys to growing spectacular dahlias. Plants are usually purchased as dormant tuberous roots, although seeds and rooted cuttings are also available.
Dahlias are frost-sensitive, so wait until mid-to-late May before planting in the garden. Plant the tuberous root 3-5 inches deep in loose soil. Cultivars taller than 3 feet will need to be staked; use a strong stake since big dahlias can be heavy! Keep the soil moist, but not excessively wet.
Avoid deep cultivation, as dahlias are shallow-rooted. When the plants have 3-4 pairs of leaves, remove the center stem above the top set of leaves. This process called "pinching" diverts growth into side branches. To increase the size of the flowers, remove the two buds on either side of the central bud. The dahlia root will not survive Minnesota winters and must be stored throughout the winter. After a killing frost, cut off the plant at ground level, dig up the roots and allow them to dry before storing at 40-50 degrees with moderate humidity. Learn more about planting dahlias
Additional Photos
