The World of Trees
by Michelle Le Strange, Master Gardener Advisor

The National Arbor Day Foundation offers the following facts and tips about trees.

A Tree-Planting Record
If your muscles ache after planting a few trees, consider this report from Florida. In June 1974 an arborist and his husky crew of 8 seasonal workers planted a total of 27,000 trees in a single day! The tiny spruces and Douglas firs were planted by hand with hoe-like mattocks on steep terrain near the Okanagan Valley in British Columbia. It took almost 14 hours and the work was monitored for correct planting procedures. In fact, survivability was reported to be a respectable 90% after 5 years. The arborist says it all began with a $300 bar bet, when someone said his crew couldn't plant 25,000 seedlings in a day!

Replanting New Trees into Old Tree Sites
When a large dead tree is removed from your property, usually a stump grinder is brought in to gobble up as many roots as possible. The question that often arises is: "Can I replant directly into that area?

First, it is better if the old stump is entirely removed, not just ground down six inches or so as is sometimes the case. Root decay is a slow process and wood rotting fungi and mushrooms will be popping up all over your landscape for many years. Also it is best to remove most of the soil/sawdust mixture and replace it with new topsoil appropriate for the tree you intend to plant. Cellulose in sawdust and wood chips will rob your soil of nitrogen as it is broken down by naturally occurring soil bacteria. Add the sawdust mixture to the compost pile or mix it with a larger mix of other organic materials to lessen its concentration.

Help Stop Lawnmower Blight
Want to know what you can do to help promote better tree health? One of the most overlooked causes of tree problems is lawnmower or weed whacker blight. It is not actually a disease, but rather the damage to bark near ground level caused by scraping or banging equipment into it. Any time outer bark is cut or broken off, the thin layer of living tissue called inner bark or phloem, and an even thinner layer of cambium cells, may be killed. These cell layers respectively, transport nutrients through the tree and produce new wood for growth. Death of these important cells results in loss of vigor and an entrance point for fungi that eventually cause decay. The solution? Use mulch around trees or otherwise simply keep lawnmowers and weed cutters away from tree trunks, they are more sensitive to damage than most people realize.

World's Largest Tree
When it comes to pure bulk and weight Mexico's Tree of Santa Maria Del Tule may hold the honor of being the world's largest tree. A team of tree experts measured the tree and found it to be 38 feet in diameter, 141 feet tall, and 150 feet across its crown. The 3,500 year old tree is a Montezuma cypress (Taxodium mucronatum) located in the village of Tule just north of Oaxaca. The tree is reported to be in good health.

Trees Pay Off
As you rake leaves this fall, you will join others in asking - are trees worth it? Nationwide, municipal officials ask the same question as they face tightening budgets. According to a USDA Forest Service study the answer is a resounding "yes!" Researchers found that practical benefits alone far exceed the costs of planting and maintaining trees. Using an example of the costs and benefits of planting 95,000 trees in the Chicago area, it was estimated that a net benefit of $38 million would be realized over 30 years. Trees also provide the service of reducing air pollution and increasing energy savings to business and homeowners.

Ornamental Plantings Deter Graffiti
No one knows for sure what it is about vegetation, but for some reason it has been found to offer effective prevention of graffiti. Retired UC Horticulturist, Ted Stamen, from Southern California surveyed more than 30 local sites that would be expected to attract the attention of taggers. Ninety percent of the sites with no vegetation had graffiti. Conversely, at sites with trees, shrubs, vines or even weeds, ninety percent were free of graffiti. Perhaps the taggers don't want their work obscured, or maybe the perpetrators are just afraid that something living in the vegetation will crawl up their legs!

November 20, 2003