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Guide to growing dahlias

Beautiful bloom of the dahlia
Beautiful bloom of the dahliaJames Austin

Of all flowering specimens available for the garden, the dahlia is undoubtedly one of my favorites. They are planted throughout my garden and cultivars range from those with blooms the size of a plate to plants that reach no more than four inches in their entirety. Many are fragrant and the diverse dahlia selection available to gardeners is huge.

There are more than 20,000 cultivars of this fabulous specimen, which is continually growing as several new hybrids appear each spring. It seems that I am not the only one with an interest in the dahlia flower.

The diverse character of dahlia does not end there. Dahlias are perfect for companion planting in the vegetable garden, repelling bad nematodes which can damage growing vegetables.

Planting dahlias

For the best performance from this flowering beauty, take time to look over your planting area and make sure it meets a few qualifications.

Sunlight: Dahlia tubers grow best in full sunlight.

Room for Growth: Allow room for root growth below ground. Holes for planting dahlia tubers should be amended 12 inches down, 12 inches wide and the tuber planted six inches below the soil level on top of the amended soil. If you wish to plant shorter flowers surrounding the dahlia, do this in spring after the dahlia tuber is securely growing in its spot.

Quality of the Soil: Dahlia performs best when planted in rich, well composted, well draining soil; with a pH of 6.2 to 6.7.

When planting dahlia tubers, make sure the eye is facing up. Stake tall specimens when planting as doing this later may damage the growing tuber and injure future flowers.

Deadhead and disbud

Remove wilting buds promptly to encourage growth of more dahlia flowers. Disbudding, the process of removing buds from side branches, directs growth into top flowers, making them stronger, larger and more eye-catching

Dahlia is a heavy feeder and when properly fertilized will reward you with the most abundant of blooms. Top dress with organic compost or use a fertilizer designed for blooming flowers.

If you live in zones further north than 7, locate dahlia in a micro-climate to avoid digging them up for storage in the winter. A micro-climate suitable for this aspiration may be an area protected by your home or another building, in a low lying area not subject to wind gusts. Most often the micro-climate should be south facing and get early morning sun. Mulch heavily in winter, particularly in colder areas.

If you must dig dahlia tubers for overwintering, store them in moistened sawdust in an area where temperatures won't get below 40 degrees.

Dahlias are a showy addition to the flowerbed, long lasting as cut flowers and a beneficial specimen for the vegetable garden. Plant a few to show off your gardening expertise.