Glittering Autumn Landscape

It is true that this year's autumn colors were affected by late summer drought and high heat. However, even as many leaves are crispy and brown, others now are brandishing their colors in final, glorious defiance of winter, which is coming rapidly. Rain and wind have been bringing these leaves down in great showers. When the weather cleared yesterday, I hurried ouside to take some photos of the display before it is gone. The landscape literally was glittering in the sunlight.

In general, the following trees and shrubs in my garden produce the following colors: 

Hickory trees (Carya), Redbud trees (Cercis), Forsythia, and Winterberry (Ilex verticillata): yellow and gold. 

Maple trees (Acer), Oak trees (Quercus), Dogwood trees (Cornus), Oakleaf hydrangeas, Blueberry, and Burning Bushes (Euonymus alatus): red, orange and purple.

Crepe myrtle trees: yellow, orange, and red.

Clockwise from top left: Oak; Winterberry; Oakleaf hydrangea; Japanese maple.

The Japanese maple 'Orido Nishiki' is green, with a touch of white variegation, through the summer, but the fall foliage is always spectacular:

More autumn scenes around the garden:

This tree with fantastic bark is a trident maple (Acer buergerianum).

I hope you enjoyed my glittering fall landscape a bit as much as I have! Best wishes to you all,  Deb

Disaster: Ambrosia Beetles in a Special Tree

There is a 26-year old Japanese maple near the house, visible from our dining and living room windows. It is one of several Japanese maple seedlings I planted in 1990 after a tornado devastated our property. It has matured into an astonishing specimen with multi-colored leaves that are breathtaking, especially in fall when they glow with fiery magnificence.

The Japanese maple in front of the house can be seen here, behind the arch in this fall view of the front garden.

It has always been a healthy tree, until last week when I noticed that some of its leaves were dying. At first I attributed this to heat stress, but then I noticed a pile of sawdust at its trunk. Closer inspection revealed unmistakable borer holes, and my heart sank:

I emailed photos to an entomologist at the Plant Diagnostics Lab at Auburn University, and I soon had a grim diagnosis: Granulate Ambrosia Beetle. Most ambrosia beetle species don't ingest wood tissue; instead, the sawdust resulting from their excavation is pushed out of the borer holes, forming little columns of sawdust. This is exactly what is seen on my tree. Females bore into twigs, branches, or small trunks of susceptible woody plants and excavate a system of tunnels. They feed on a symbiotic fungus that they introduce into their tunnels. High humidity promotes reproduction of ambrosia beetles, and we have had a very humid summer. Eggs, larvae, and pupae are found together in the tunnel system excavated by the female.

Photo of Granulate Ambrosia Beetle with pupae and black fungus. Photo from Wikipedia.This insect usually attacks apparently healthy hardwoods less than 3 inches in diameter, and their appearance in larger wood often is an indication that the tree is highly stressed or dying, although my tree did not appear stressed or dying until this beetle attack. Prognosis is poor. There are no chemicals that one can apply that will kill ambrosia beetles inside a trunk. Systemics will NOT work as the beetles are inside the vascular tissue of the tree.

Mine is an older tree with a number of trunks. Since some of the trunks are affected and others not, the entomologist recommends that we remove the infested trunks and dispose of the wood. So this is what we are going to do. It will greatly affect the shape of the tree, and the tree may yet die.More leaves have died in the past few days. One can clearly see which trunks are affected.

This Japanese maple provides filtered shade to nearby azaleas and ferns, and it also keeps hot sun from shining directly into the house. If it dies, I will greatly miss it. However, I have learned to adapt to what nature hands me in the garden. I am already thinking about how I will replace it, if that becomes necessary.