Our woods are full of native dogwoods (Cornus florida). In the spring, their white “flowers” provide a colorful and very beautiful effect in the awakening forest. We’re just beginning to see that this week. In a few days, the woods will come alive with soft clouds of white as the dogwood bracts expand to their full size.
Dogwoods of various sizes and stages of maturity are the dominant understory trees in our woods. At the time they come into bloom, the woodland is still colored in the browns and grays of the bare oaks and hickories and the tan shades of the leaf covered forest floor. This dark backdrop really allows the white dogwood blooms to stand out.
One of my strongest memories of these beautiful trees comes from when I was doing research in the Sandhills region of North Carolina. The flowering dogwood is the dominant understory tree in the longleaf pine forest where we were studying the southeastern fox squirrel. In the spring, the dogwoods would burst into bloom before anything else and the beautiful layers of white blooms stood out brilliantly against the dark trunks of the tall pines and the carpet of pine needles on the ground – absolutely stunning! I really wish I had a picture.
There is a really interesting story about the growth form of these trees and how it varies depending on the amount of sun they receive. Dogwoods that grow under the shady conditions of mixed hardwood or pine forests develop a unique growth pattern which truly adds to the beauty of the tree and its overall attractiveness in the woodland setting.
In the shade, these trees (as well as many other understory trees) tend to have a sparser crown with branches that spread out horizontally resulting in a rather flat-topped, layered appearance. When these dogwoods come into bloom, this horizontal branching pattern is especially obvious and it creates a really beautiful effect – like low clouds floating through the forest.
The branches of woodland dogwoods are arranged in alternating layers so that one branch never shades the branch growing below it. This allows all leaves to have maximum exposure to the available sunlight. This form develops as the tree grows because branches that are heavily shaded by another branch eventually die off due to lack of sun. The branching pattern, called monolayering, allows the tree to maximize photosynthesis under the lower light conditions that occur in the interior of mature forests.
In contrast, dogwoods that grow in more open habitats where competition for sunlight is not a factor usually have a much denser crown with overlapping layers of branches (multilayered).
In the forest, the majority of the sunlight reaching a tree comes from above, while in an open field, light reaches the tree from the sides as well. This allows more branches to harvest sunlight and the airy layers seen when the trees are growing in shade are much less pronounced or even lost all together.
We have a beautiful dogwood that is growing out in the open on the way up to our orchard. This tree, which is exposed to much more sunlight, shows the very striking difference between the two growth forms.
Trees grown in the landscape in full sun or high shade often have more lower branches than forest trees of the same species. When you walk through the woods and see an old tree with massive lower branches you know that this tree once held vigil over a field or clearing. If you find a tree that has large branches on one side only, then it is probably growing or once grew at the edge of a field with the lower branches pointing towards the field.
Here’s one more bit of interesting tree growth trivia:
When trees are planted for timber harvest, the seedlings are planted close together to discourage the development of lower branches which would form knots in the wood and reduce the value of the timber.
Such cool stuff! Next time you are walking in the woods or around your yard take a look to see how the dogwoods grow!
Until next time – Happy Gardening!
Your article on Dogwood was lovely. I have 2 ‘domesticated’ trees in my gardens. One is white and other pink. The pink one looks so ‘thin’ compared with white one. It has nice rounded shape but far less branches. Both get about same sunlight. Is this a good time to prune the dogwoods or wait til after it finishes blooming? I did cut off the lower ‘odd’ branches’ and both now have nicer shapes. Also, the pink tree’s trunk near the ground looks very deformed. Could it have been grafted? Does that make it weaker? My sis in law in Durham NC told me recently that we will be losing lots of dogwoods due to some spreading fungus. True? Anything I should be doing? Will the jillion ‘inch worms’ we are covered in right now hurt the dogwoods? ( those darn things would be welcomed topic for article!) I did spray everything I could reach with Sevin last week at the worst of invasion. Have lots of jap maples they were/are munching on. Finally, could I send you photo of my problem pink dogwood? Thanks again for your delightful articles. I always wait to read them with a fresh cup of coffee in the morning while I enjoy the view of my Japanese Garden. Like sitting & chatting with a good friend!