Dogwoods – Trees and Shrubs

  • Post published:06/03/2017
  • Post comments:2 Comments
Kousa dogwood
Kousa dogwood

With its long lasting flowers the dogwood is one of the iconic trees of early spring. On my street there are two beautiful dogwoods, Cornus florida, a native species. We are fortunate to have these trees because in the past this species has battled anthracnose, the most deadly fungus that can attack dogwoods.

The response to the dying off of many native dogwoods is the rise of Kousa dogwood, a Japanese species. The flower is very similar but the tree blooms a bit later in the spring. Both native and Kousa dogwoods are categorized as small trees, which means they will attain a height between 15 and 30 feet with an equal spread. Thirty feet does not seem very small to me.

These two dogwood species produce similar long blooming flowers, but the ‘flowers’ are actually white or pinkish bracts surrounding the very tiny true flowers in the center. There is an old legend that says Satan tried to climb over the wall that surrounded Eden to knock the flowers off Adam’s favorite tree, the dogwood. However, he fell and since the blossoms were in the shape of a cross, all he managed to do was take a tiny bite out of the petals. That bite is recognizable today.

Both species also have good fall color with shades of pink and red, and they produce berries that attract the birds.

Kousa dogwood flowers
Kousa dogwood flowers – closeup

I considered planting a native or Kousa dogwood in my new garden, but gave up the idea because I decided that it is too wet for dogwoods to thrive. These trees do enjoy some shade, and moist but well drained soil, but I feared that our floods would be fatal.

Although the dogwood trees don’t like water, dogwood shrubs don’t seem to mind at all. One of the first large shrubs I planted in the garden in the summer of 2015 was the yellow twig dogwood. This multi-stemmed shrub will reach a height and width of five or six feet and has grown energetically for us. I wanted this shrub because the yellow stems attract a lot of attention in the winter and spring. It’s a true glory when the sun is shining on it. I planted Cornus sericea  Flaviramea  right where I can see it from my kitchen window.

Yellow twig dogwoods are so water tolerant that they can be used as part of a rain garden planting which means they can stand periodic flooding and full time dampness.

I was so happy with the yellow twig that last year I bought two more dogwood shrubs. Many people are familiar with the red twig dogwood, Cornus sanguinea. It will attain the size and stature of the yellow twig but the stems are a very definite red. I saw a house with a red twig dogwood hedge once during the winter. It was nicely pruned and quite elegant.

The second new dogwood shrub is an osier Cornus sericea. The word osier threw me. It brought to mind certain willows with very flexible stems that could be cut while young to make baskets and furniture. I wondered whether the osier cornus could be used the same way. I have not yet made that determination

I was also confused because this was a C. sericea like the Flaviramea, but it was not a stunning yellow, nor was it red, but rather a mixture. The horticultural world is not always easy to understand. However this species is also extremely water tolerant and it has become the tallest and most upright of my dogwood shrubs. It must like its wet spot, next to a planting of primroses that are also happy in the wet. These three shrubs benefit from cutting back some of the stems every two or three years to keep the color vivid.

All three of these dogwoods have similar flowers. They lack the showy bracts of the trees. They have small flat-topped clusters of tiny true flowers that are not showy at all. However, in the fall small drupes replace the flowers. Drupes is a new word for me. – easily defined. Drupes are a stone fruit, with a fleshy outer part surrounding the pit. Peaches, plums cherries and other stone fruits are drupes.

Pagoda dogwood blossoms
Pagoda dogwood blossoms

The final cornus in my planting is a pagoda dogwood, Cornus alternifolia. This is another small dogwood tree, but it has flowers and drupes just like the shrubs. No show off bracts.  The alternifolia in its name refers to the leaves which appear alternately on the stems instead of opposite each other on other cornus species.

My desire for this tree is because of the fairly horizontal arrangement of its branches much like the levels in a pagoda. I love the sculptural arrangement, but I know it will take some regular pruning to urge it on to its best form. I am not a great pruner but I am ready to accept the challenge.

I want to make a final small mention of the low growing Cornus canadensis otherwise known as bunchberry, bearberry or any one of several names including plain dwarf dogwood. It is easily recognizable as a dogwood by its foliage and the white bracts surrounding its true flowers. The only difference is its petite size. It creeps along the ground, only eight inches high and spreading two or three feet. Birds eat the red berries in the fall and spread the seeds elsewhere.

The interesting thing about bunchberry is the force with which its flower buds bend back and the anthers spring forward in less than a millisecond and throw the pollen into the air and surrounding garden at more than two thousand times the force of gravity. I don’t know how anyone ever saw or measured this phenomenon but you can find videos on YouTube.###

Between the Rows   May 27, 2017


This Post Has 2 Comments

  1. Lisa Greenbow

    Since you have such a wet garden have you thought about growing button bush? I just love those blooms and the birds like the shrub too. I like your dogwood shrubs. They are such good garden plants. They take a lot of abuse and keep on growing and look nice during winter too.

  2. Pat

    Lisa – I do have a button bush and it is thriving. Not blooming yet but you can expect to see it celebrated in its season.

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