Seeing the Forest for the Trees

It’s tree-planting time, perfect for gardeners who yearn for the rural, peaceful feeling a tree gives a yard. The trouble is, many trees planted each spring are not good choices.

“If you own an estate with lots of space, there are thousands of trees to choose from, but most people in Orange County have postage-stamp sites, which narrows down the list of acceptable trees,” says Fullerton arborist Alden Kelley.

The list may be shorter, but there are still plenty of smaller trees to select from, adds Fullerton horticultural consultant Beverly Schmidt. “Many trees do well in small spaces, including large shrubs that can be trained as trees.”

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The secret to success with landscape trees is simple: Plant the right tree in the right place.

“Ideal trees are those that won’t naturally outgrow their space and don’t require a lot of maintenance once they begin to mature,” Kelley says. “Determine what kind of home you can offer a tree above and below ground, and find a tree that can comfortably live there indefinitely.”

Many larger tree species will work for a few years in most yards, but people need to think 10 to 15 years ahead, or more. If you don’t, you and your tree will suffer the consequences later.

Trees that are too large for a yard can wreak havoc: tearing up sidewalks and driveways, threatening the foundations of houses and pools and running into utility lines.

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Perhaps most tragically, many trees grown in inadequate space die young (at 5 or 10 years of age), or must be continually subject to disfiguring and damaging pruning.

Utility companies such as Southern California Edison routinely cut back trees that are near power lines to ensure continuous, safe electrical service. Edison prefers trees to be at least 15 feet away from electrical poles and, generally, less than 25 feet high at maturity.

“To prevent disruptions in power service, Edison maintains 1.2 million trees belonging to cities and private people throughout Southern California and spends in excess of $28 million a year on tree trimming,” says arborist Randall Williams, manager of line clearance for the company.

“At Edison, we don’t want to mutilate trees, but our company is required by law to keep power lines clear of trees. A number of things--besides power outages--occur when electrical lines get too close to trees. The possibility increases for fire, personal injury and electrical surges that cause problems for computers and appliances like refrigerators.”

Even if your tree doesn’t threaten a structure or power line, not having enough room for it will cause a lot of extra work.

“Trees will often grow in a tight root volume, but as they get older and bigger, they’ll require more specialized care,” Kelley says. “The watering program will have to be precise, the draining impeccable, and you may also have to add liquid organic fertilizer, because the tree’s limited root room will prevent it from mining new soil for minerals. You may even need to bonsai some trees.”

Commonly grown trees that continually cause problems include many palm trees, many ficus, coral trees, evergreen ash (Fraxinus uhdei), Eucalyptus globulus and Eucalyptus camaldulensis.

Southern California Edison’s biggest problem is the palm tree, which Williams says causes 25% of vegetation-related outages.

“The trouble with palm trees is that you cannot prune off their tips without killing them,” Williams says. “Palm fronds can sometimes be trimmed while the palm grows past the wires, but the dead fronds often fall onto the lines and start fires or power outages.”

Underground lines being put in new developments might seem like a logical solution, but they have their limitations.

“Underground lines take much longer to fix when there is a storm, because it is harder to pinpoint the location of the problem,” Williams says. “Tree roots can also be damaged if our workers have to dig up the lines for repairs.”

Although you may not be able to plant a large tree in your backyard, there are many trees that will grow in smaller spaces. To make the best tree selection for your yard, keep in mind the following tips:

* Look up and look down to determine where the tree will be in relation to overhead and underground utility lines and other structures. Overhead lines can be for electric, telephone or cable television. Underground lines include the above three, plus those for water, sewer and natural gas.

Before planting, verify that you won’t be digging anywhere near underground utility lines, which can be dangerous.

Finding out if you’ll be digging near underground lines is easy, says Ron Olitsky, president of Underground Service Alert, a company that sponsors Dig Alert ([800] 227-2600). The free service will tell you if the area you want to dig in has any underground lines.

* Measure everything, including how much growing room there is for the tree above and below ground. Check the ground’s surface area and the distance to which the tree branches will grow, including their length, width and height.

Consider soil volume requirements. Usable root space refers to soil that is deep enough (2 to 2 1/2 feet) for roots to grow, drains well and is not compacted; oxygen and moisture must be able to get to the roots. Also consider the tree’s expected trunk diameter (caliper) at maturity, which will help determine how much root room it will eventually require.

Generally, a small tree will thrive as long as it has 35 to 50 cubic feet of good soil for every inch of trunk diameter, Kelley says. (Measure diameter 4 1/2 feet from the ground.) If the trunk diameter is 8 inches, a tree up to that size can manage in 300 to 400 cubic feet of soil.

* Visit the Fullerton arboretum or local parks and ask to see trees that you’re considering in their mature state.

* If you want trees for screening purposes, consider vines, which do an excellent job of blocking views without growing unusually large.

* Plant trees away from your property line, Schmidt advises. “This prevents squabbles with your neighbors,” she says. “Although the concept of shared trees is a good one, in reality it causes too many problems.”

For more information on proper tree selection and on keeping them away from power lines, check Southern California Edison’s Web site on this topic: https://www.ag .uiuc.edu/~isa/consumer/avoid.html.

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Trees for Small Areas

A List: Readily available; easy management

* Bronze loquat (Eriobotrya deflexa)

* Coral gum (Eucalyptus torquata)

* Emerald cascade acacia (Acacia cognata ‘Emerald cascade’)

* Gold medallion tree (Cassia leptophylla)

* Redleaf photinia (Photinia fraseri)

* Saucer magnolia (Magnolia soulangiana)

* Sweetshade (Hymenosporum flavum)

* Strawberry tree (Arbutus unedo)

* Western redbud (Cercis occidentalis)

* Willow pittosporum (Pittosporum phillyraeoides)

* Wilson holly (Ilex altaclarensis ‘Wilsonii’)

B List: More maintenance and training

* African sumac (Rhus lancea)

* Bailey acacia (Acacia baileyana)

* Brazilian butterfly tree (Bauhinia forficata)

* Citrus knife acacia (Acacia cultriformis)

* Crepe myrtle (Cherokee pecos, seminole, zuni only)

* English holly (Ilex aquifolium)

* Eucalyptus (E. ficifolia only)

* Evergreen pear (Pyrus kawakamii)

* Firewheel tree (Stenocarpus sinuatus)

* Flaxleaf paperbark (Melaleuca linariifolia)

* Freeman magnolia (Magnolia ‘Freeman’)

* French pussy willow (Salix caprea)

* Golden trumpet tree (Tabebuia chrysotricha)

* Lemon bottlebrush (Callistemon citrinus)

* Lily-of-the-valley tree (Crinodendron patagua)

* Loquat

* New Zealand Christmas tree (Metrosideros excelsus)

* Pacific wax myrtle (Myrica californica)

* Pineapple guava (Feijoa sellowiana)

* Pink trumpet tree (Tabebuia impetiginosa)

* Pussy willow (Salix discolor)

* San Marino magnolia (M. grandiflora ‘San Marino’)

* Strawberry guava (Psidium cattleianum)

* Tristania laurina

* Toyon (Heteromeles arbutifolia)

* Victoria magnolia (Magnolia grandiflora ‘Victoria’)

* Weeping acacia (Acacia pendula)

* Weeping bottlebrush (Callistemon viminalis)

* Xylosma (Xylosma congestum)