Our dogwood friends have started blooming, and a few on the backyard tree still had their eyes closed this morning- a great opportunity to really savor each step of their development. Unfortunately, I am focusing on this tree today because she is suffering and needs a diagnosis.
You can see the leaves emerging like tiny fists of green from the branches below. The leaves look green and healthy, though this might have more to do with their novelty than their general well-being.
Dogwood berries turn red in September as a signal to the birds that the seeds are ripe and ready to be eaten by birds (squirrels eat them too, but they chew up the seeds in the berries). The birds swallow the berries, digest the “meat” off the seeds, and then the softened seeds pass through the bird’s digestive system. Many of the white woodland dogwoods seen blooming in the spring were planted by birds!
To diagnose our dogwood, Max and I are flipping through the field guides and looking online. For novices like us, dogwood diagnosing works by process of elimination. For example, we don’t suspect Dogwood Anthracnose because the leaves are not affected- only the flowers or bracts. Yet this anthracnose is caused by a fungus, which would make it a recurring problem, and Max says he remembers the flowers looked this way last year as well.
So we did some more research on the fungus which causes anthracnose, and we found something that didn’t suit our fancy. It looks like our friend is suffering from spot anthracnose. According to plant pathologists at North Carolina State University:
Spot anthracnose, caused by Elsinoe corni, affects the flower bracts (petals), leaves and young shoots. The most conspicuous symptoms are small (1/25 to 1/16 inch in diameter), circular to elongate reddish-purple spots on the bracts in early spring. The spots may become numerous and merge, losing the distinctive characteristics of individual spots. Severely infected bracts may be stunted and disfigured and fall prematurely.
Spots on leaves are very small and dark purple in color, but the centers may turn pale yellow-gray and drop out. Heavily infected leaves are smaller than normal, distorted and often killed. Infected young shoots and berries develop elongated, scabby lesions with a purplish margin. The causal fungus produces spores on the lesions, and overwinters on infected twigs and fruit.
And so we have our answer. Now time for the solution. This part led Max to a little despair, since now we must examine the extent to which our tree has been affected and determine whether it can be saved. Not exactly what I had hoped when I lured the munchkins to the dogwood blooms this morning…..
On the other hand, if worse comes to worse, we can harvest some seeds from the dogwoods in the front yard and try to plant some healthy dogwoods in the backyard. The cycle of life is not always easy to explore with kids when it involves the possible dying of a favorite climbing-hammocking-fort tree.
MORE DOGWOOD EXPLORATIONS:
Best Ever Flowering Dogwood Coloring Page (PDF from MEEEA)
Selection and Care of Dogwoods (PDF from ACES)
Cornus florida Fact Sheet (PDF from US Forest Service)
Flowering dogwood (University of Alabama Arboretum)
How to harvest dogwood tree seeds (Ehow)