Lesson 6: Trees And Shrubs
Pest Trees
There are certain trees that are totally inappropriate for residential gardens. Anyone who has ever experienced dealing with a “pest” tree knows what a nightmare they can be. What qualifies a tree for this title?
A perfect example of a pest tree is the ornamental pear. In the Spring, it produces millions of sticky white blossoms that adhere to shoes, walkways, patios and stairs. The blossoms smell like codfish and bleach. In addition, it produces millions of tiny round pearlets that rot, fall on the ground and stain everything. Unless you have acreage, and this tree is planted well away from any dwellings, don’t plant it.
The Chinese tallow is officially listed as a pest tree. There is an alert on the highly popular and ornamental Chinese tallow tree. Recently the California Exotic Pest Plant Council placed it on their "red alert" list of species with the potential to spread explosively. The Nature Conservancy´s "Dirty Dozen", lists the tallow as a pest. A mature tree can produce 100,000 seeds annually. If you garden near wetlands or native plant habitats, it´s best not to plant this tree.
Eucalyptus have been found to be extremely flammable trees due to the volatile oils they contain. In high heat they can implode. They also topple in high wind, and their branches easily snap off, creating hazards.
Sweet gum and willow are invasive trees that have root systems which can destroy plumbing and buckle foundations.
This is why it is so very important to understand the trees you are thinking of planting in your garden.
Assignment: Before selecting any trees, find out which trees are considered pests in your community.
