Dahlias

Dahlia blooms are one of my favorite flowers.  They are so exquisite and beautiful.  They brighten up the garden throughout the season and come in so many diverse colors and petal varieties.  There are single petaled types and those with dense mounds of petals.Colors are vary from stunning to subtle and soft.
  

Taken from Rodale's Organic Gardening Encyclopedia p. 172

Dahlia sizes are as variable as petal variety.  There are dinner plate size flowers or small one to two inch diameter flowers. They can be used in containers, borders, or as a focus in a cottage garden flower beds.  They are also beautiful inter-planted in the vegetable garden among broccoli, cauliflower, and celery. They are my favorite cut flower to bring indoors singly or in a bouquet.

Grown from seed.

Dahlia's inter-planted among broccoli and cauliflower.

  Dahlia sizes are as variable as petal variety.  There are dinner plate size flowers or small one to two inch diameter flowers. They can be use in containers, borders, or as a focus in a cottage garden flower bed.  They are also beautiful inter-planted in the vegetable garden among broccoli, cauliflower, and celery.

Grown from a tuberous root Thomas Edison cultivar.

Growing Description:

Dahlias can grow from 1-6' tall depending on the variety.  They spread 1-3' wide and have thick stems with lush green foliage.  They are hardy in zones 8-10 but where the soil freezes the tubers must be lifted before the ground freezes or else the tubers will freeze.

Dahlias are grown from tuberous roots.  Tuberous roots are swollen fleshy roots.  They have a pointed bud on top and roots that sprout from the bottom.  

 

Optical Illusion a tu-toned dahlia

Lifting Dahlia Tubers:

They are hardy in zones 8-10 but where the soil freezes the tubers must be lifted before the ground freezes.  After frost blackens the plants, cut them back to a few inches above the ground and lift the clumps with the soil intact out of the ground.  Lay them on their side until the soil dries.  At this point they can be stored at 45-50 degrees with the soil still intact or remove the soil and place them in peat moss.  Be sure to label the cultivars.  Occasionally sprinkle with water so tuberous roots do not dry out.   You can divide the clumps in spring just be sure that each planting includes a pinkish "eye."  (Rodale's Organic Gardening Encyclopedia)

How To Grow:

You can purchase dahlia roots from various seed catalogs.  They come in plastic bags surrounded by peat moss.  They must be planted after all danger of frost is gone.

Prepare the soil first.  They need full sun and soil with abundant organic matter.  Put a handful of bone meal into the planting hole and along with compost.  Mix with existing soil.  Set the tuberous roots 3"-6" below the surface.  Do not cover completely with soil.  Gradually fill in the hole as they grow, similar to potatoes.  Drive a sturdy stake 6" from the tubers if you have tall cultivars before they begin to grow.  If you wait to put your stakes in after they have grown you may injury the tuberous roots.  

Mulch around plants.  Dahlias need frequent watering and enjoy frequent applications of fish emulsion fertilizer.

Encouraging Flowering & Large Flowers:

If you want to encourage branching and more flower production, then when the plants are 6-8" tall pinch out the center.  You can repeat this after another 6" of growth appears.  

To encourage large flowers you can pinch off the side buds so the energy is directed to the center bud.  Do this when the buds are small around the size of a pea.  Or leave all buds on and you will have smaller but more flowers.  

Vancouver a cactus cultivar.

Growing From Seed:

This year I grew some dahlias from seed and they are gorgeous.  I inter-planted them among broccoli and celery in the vegetable garden. 

Certain cultivars of dahlias flower and bloom well if grown from seed.  You can purchase seed for double dahlias which have 2-3" flowers.  Single dahlias are a smaller plant and look beautiful as borders and in containers.  The larger dahlias need to be grown from tuberous roots. Below are all dahlias grown from seed.

You can store the roots from those you grow from seed as well.  Start them indoors in late winter and then transplant out after a frost.  They will give you late summer and early fall blooms.

Dahlias in a old wash tub.