Trees: Cherished addition or costly mistake
BYMAUREEN GILMER DIY Network

SHNS photo courtesy Maureen Gilmer Know the height and diameter of the tree at maturity to determine if it is suited to your home site.

Real estate appraisers all agree that a beautiful tree can improve the beauty and value of your home. But trees behaving badly can become a huge liability, causing a nightmare of clogged plumbing, broken concrete and persistent litter.

So how does a homeowner choose the right tree for his or her yard? It's easy if you systematically eliminate all trees that don't fit your criteria. The result will be a short list of perfectly matched candidates.

Here's how to create your list:

Avoid problem rooters

Unless you live in an expansive rural home, begin by eliminating trees that are notorious problems because of aggressive rooting. Roots seeking water will damage water lines, septic systems, sewer pipes and underground cisterns.

Cross off all water-seeking species like poplars, alder and willows, plus drought resistant fruitless mulberry and locust. Surface rooted trees will crack paving, foundations and curbs as roots grow large with time. Do away with eucalyptus, sycamores, maples and Indian figs.

Beware trees too large for the space

Trees that mature at 50 or 60 feet are far too large for the average yard and can easily overwhelm a smaller lot. There's no clue to its ultimate size when you see a tree in a nursery pot. Read the label carefully to know the eventual height and canopy diameter of a tree at maturity. That's the only way to know if it will fit your site. Hard pruning to force a tree to fit is not an option; this disfigures a tree and is expensive.

First determine the size of the area in the yard you'd like to shade, then look for a tree with a canopy to match. If you want to shade a 20-footwide patio, exclude all trees that are more than 20 feet in diameter.

Avoid litter bugs Nobody wants a tree that sheds excessive leaves or litter. This is especially vital near sidewalks, parking areas, outdoor living spaces and swimming pools. Know what kind of flowers or fruit the tree produces. Any with fruit can stain paving irreparably, and birds can compound this effect. Avoid those with small marble-like seeds, a serious hazard to foot traffic. Pay special attention to evergreens to determine if that species is a year-around needle shedder.

There are other factors to consider as well. Although they're tempting, avoid fast growing species because they often share weak branching and an unusually short life span.

And research the species and named variety, if applicable, to determine if it's vulnerable to any specific life threatening diseases such as Dutch Elm Disease. Remember, too, that some diseases such as sycamore mildew may not kill the tree, but will disfigure it enough to spoil the beauty.

Know as well your local USDA cold hardiness climate zone number. Match this to the designation of any potential tree. The tree must be cold hardy to at least that zone if it is to thrive in your landscape.

Tip: For a short cut, obtain a copy of your city's official street tree list, usually available through the local building or planning department. Local experts have gone through this same process to compile lists of trees that root properly, fit the street, lack litter, are resistant to pests and disease and that live a very long time.

While most homeowners begin with flowers or fall color to pick out their trees, these are among the very last criteria you should consider. The finalists that have survived your elimination process can now be compared for their aesthetic qualities to find the one you like the best.

Planting a tree is a longterm investment of time, money and care. It can grow to become the most beautiful part of your home site or into an enormous liability. Take time to do your homework. A good choice will give your decades of enjoyment beneath its sheltering branches and then will add thousands to the value of your home when it eventually comes time to sell.

(Maureen Gilmer is a horticulturist and host of "Weekend Gardening" on DIY Network. Contact her at her Web site www.moplants.com or visit www.diynetwork.com.)