If you attended a county or state fair this summer, chances are the blue-ribbon winner in the horticulture competition was a dahlia. These flowers are so intricate and stunning, there must be infinite fields of them growing blissfully in heaven.
Dahlias are native to the mountainous regions of Mexico. They were first found and described among the Aztecs. In 1570, King Phillip II of Spain sent Francisco Hernandez to Mexico to study the natural resources of the country. The first drawings were made of the dahlias by an associate who was traveling with Hernandez and were published in 1651. The flowers are named for Swedish botanist Andreas Dahl, who in 1789 traveled to Mexico and studied its flora. Dahl was a pupil of Linnaeus and made some of the first, original hybrids from plants he brought to Sweden from Spain and Mexico. The results are extraordinary, and to think, we can grow them relatively easy right here in our diocese.
Dahlias perform best in full sun and well-drained soil. If the soil stays wet, they may rot and die away. Their tubers spread out in the shape of the spokes on a wagon wheel. When buying them, from our local garden shops, carefully inspect each tuber and make sure they are firm without any signs of damage and rot. If they have sprouted, snip back the new growth to a length of one inch. This will not hurt the dahlias and will actually encourage growth.
Before planting, drive a sturdy support into the ground such as a metal fence post, wooden stake or whatever will be used for staking. Doing this prior to planting ensures that the tubers will not be damaged by adding a support later. The time for planting outside, in Colorado, is in the spring after the temperatures consistently stay above 60°F. To plant tubers, dig a hole between 6 and 8 inches deep on both sides of the support. Place the tuber horizontally in the ground. Place the soil back in the hole. The dahlias should emerge in about 2 weeks. Note: astonishingly they don’t need water following planting — only after sprouts appear above the soil surface. When purchasing through gardening catalogs, they will generally be shipped once cold weather passes for the local climate and may have slightly different planting instructions depending on the variety. Follow their instructions.
Dahlias range in bloom size from 3 inches to 16 inches. They are available in almost every color except green, brown and true blue. They come in combination colors (pictured Bodacious Dinnerplate/Dahlia blooming now in Colorado Springs). Some grow to a height of, believe it or not, 6 feet! The leaves are medium green and can be whirled or opposite depending on the variety.
Growing tips: 1. Feeding dahlias should be done before planting and in July. Two weeks before planting, work in a 5-10-5 or 5-10-10 complete fertilizer to the planting area. Repeat in July. 2. After the dahlias reach a height of 10-12 inches they need an inch of water per week. Mulching with grass, pine needles or straw keeps the tubers cooler. 3. Deadheading improves blooms. 4. Disbudding (pinching off buds) improves flowering. Remove two sets of the auxiliary buds located beneath the main bud on either side of the stem where the leaves meet. 5. After a killing frost in the fall, remove the brown foliage and stems but leave the tuberous roots in the soil for an additional 1-2 weeks to “cure.” Carefully remove the tubers from the soil, remove the rest of the stalk, wash off as much soil as possible and let them sit until they are dry to the touch (about 1 day). Place clumps upside down in boxes and cover with vermiculite, sphagnum peat, or wood shavings and put them in the coolest part of the house, preferable between 40° and 55°F.
The dazzling days of the dahlias! Their beauty brings joy to both summer and fall. Before you know it we will be blessed with the first snowflakes of winter and our hearts will surely long for the wonderments of the garden filled with the tiny blessings that are in bloom.
(Kerry Peetz is a master gardener and a member of Sacred Heart Parish in Colorado Springs.)