Maple Tree Growing, Disease and Care

There exists a wide range of different maple trees, all belonging to the genus Acer. Examples of well knownspecies are Red maple tree (Acer rubrum), Rocky Mountain maple tree (Acer glabrum), Norway maple tree (Acer platanoides) and Bigleaf maple tree (Acer macrophyllum). The formal classification is currently being discussed. Some experts want to place them in a family own their own, the Aceraceae. Others prefer to place the genus Acer in the family Sapindaceae; the Soapberry family. (Wikipedia) The name “acer” is a very old name and its origin is unknown. It may have been derived from the Latin word for sharp, “acris”. Maple tree wood is very hard and might therefore have been a popular material for spears.

Human Utilization

Wild maple trees have played an important role for humans since ancient times, and wild as well as cultivated forms continues to be significant to use even in our modern society. Many species sport bright leaf coloring during fall and are therefore popular as ornamental plants.

The strong wood is suitable for timber production, and the Sugar Maple (Acer saccharum) is the three of choice for manufacturers of bowling alley lanes, bowling pins, butcher’s blocks etc. Maple wood is a so called “tone wood”, which means that it carries sound waves well. It is therefore commonly used in drums, guitars and similar musical instruments.

Since the Sugar Maple offers exceptionally hard wood, it is also referred to as Hard Maple. This species is however not only appreciated for its wood; it is also the species from which Canadians derive their famous maple syrup. The Sugar Maple is tapped for sap; the fluid used by the Sugar Maple to distribute water and nutrition in its tubules. Sap is then boiled until it turns into syrup. It can also be used to make maple sugar and maple candy. Quebec is the world’s most important maple syrup center and the Canadian flag depicts a stylized red maple leaf as a symbol of Canada.

Honey bee keepers also appreciate this trees, since its flowers forms an important early spring source of pollen and nectar for honeybees and other pollinators. Honeybees in many parts of the world rely on this tree for their spring buildup.

Description

A majority of the maple tree species has palmately lobed leaves, but you can also find other leaf shapes. A typical leaf will have 3-9 veins; each running towards a lobe. The maple tree flowers during late winter and early spring, and some species will even flower before any leaves have appeared. A singe flower is small and not very eye-catching, but together flowers can look really prominent; especially since they flower early in the year when few other flowers are around to compete for attention. The characteristic fruits are called “keys” and the distinctive shape will help the fruits to spin as the fall from the tree. A “key” be easily caught by the wind and transport the seeds to new areas far away from the tree.

Maple Tree Disease

Maple trees can become infected by several different diseases, such as Sapstreak disease, Verticillium wilt, Anthracnose and Tar Spot. Anthracnose is not a single disease; the name instead refers to a group of diseases caused by a collection of closely related fungi species. In a similar way, Tar Spot can be caused by several different fungi species from the genus Rhytisma.

Sapstreak

Sapstreak is caused by a species of fungus named Ceratocystis coerulescens. As far as we know, only Sugar Maple seems to be affected by this fungus. During the initial stage, you can notice how parts of the foliage, or the entire foliage, becomes dwarfed. The disease will then worsen over the course of several years, and a maple tree where only parts of the foliage was dwarfed at first will eventually have the foliage of its entire crown dwarfed. Parts of the crown will begin to die, and after 3-4 years the entire maple tree will be dead. The disease will not only affect the foliage, the lower stem and the root system will become stained. If you open up an infected tree you can see the characteristic radiating Sapstreak disease pattern in the wood.

Verticillium wilt

This disease is also known simply as Maple wilt, and is caused by the soil-borne Verticillium fungus. The resistance against Verticillium varies a lot between different species and the Norway maple tree seems to be especially prone to contract this disease. Silver maple, Red maple, Japanese maple and Sycamore maple are also known to be quite susceptible to this disease.

Verticillium fungus will typically gain access to the tree via the roots and then spread through the sapwood until it reaches the upper branches of the tree. When upper branches become infected, they begin to die. You can sometimes see sparsely located and weird looking leaves on these infected branches. Such leaves will usually wilt and die during the middle of the summer.

This disease can kill an entire maple tree within one single season, but this is uncommon. The normal case is instead one where the tree slowly succumbs over the course of several years. Several different factors will affect how long the tree manages to stay alive, including tree size and climate. Really healthy trees can even manage to counteract and limit the damage caused by Verticillium by growing new water conducting vessels that are not infected.

Anthracnose

Antracnose is caused by a group of closely related fungi species. These fungi species are not only dangerous to maples; they will cause serious problems for white oaks, sycamores, elms and dogwood as well. When birch, hickory, walnut, linden or tulip tree becomes infected, the result will usually be much less severe.

When a maple tree becomes infected with Antracnose fungi, the areas along the veins develop a mauve-brown color. You can also frequently see irregular spots of a brown shade along the veins, or between the veins. Antracnose can also cause buds to die, premature leaf drop and the development of characteristic “witches’ brooms”.