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Plant with care

Courtesy of Springfield State Journal-Register

By SJ-R Outdoors Editor Chris Young

The tornadoes were on the ground for 11 short minutes March 12 in Springfield, but there will be no quick fixes for replacing the thousands of trees damaged or uprooted.

And because trees live for decades - and some for hundreds of years - Springfield residents will have to live a long time with the tree-planting decisions they will make in the coming weeks.

Poor decisions may produce trees that don't weather future storms any better than those that were toppled. And the wrong trees planted in the wrong places could have future generations cursing us for years to come - think of the sweet-gum balls littering your yard and driveway.

In the wake of the storm, Petersburg arborist Guy Sternberg, who with Jim Wilson authored "Native Trees for North American Landscapes," offers several observations and suggestions about what trees to replant and how to keep them healthy.

First, Sternberg cautions that no tree is immune to storm damage.

"If you're at ground zero during an F2 to F5 storm, it doesn't matter much what you plant because everything will come down," he says. "What we need to plan for is the likelihood that your yard will not be on the exact center of the tornado's narrow path."

He says some trees should never be planted. "One example is Bradford pear," he says.

Bradford pears are popular, fast-growing trees that break easily even during routine Midwestern storms. "This tree - because it is seldom pruned properly - is so fragile that it usually disintegrates long before it can grow large enough to cause much damage as it falls," Sternberg says. "And now that people are planting other callery pear clones to replace the notoriously weak Bradford, they all are beginning to pollinate one another and the species is becoming invasive."

"Just say no to callery pears," he adds. "The same goes for Ailanthus (tree of heaven), Siberian elm, black alder, silver poplar, empress tree and other weak-wooded, fast-growing, invasive exotic trees."

Invasive trees can spread rapidly, crowding out natives. Some, like Ailanthus, are notoriously hard to eradicate once established in natural areas. "It can be a pretty tree in the right place - in China," he says.

In the days following the storm, Sternberg - along with other local experts including city arborist Mike Dirksen and University of Illinois Extension horticulture educator David Robson - have cautioned against planting fast-growing but weak-wooded trees in an effort to rapidly replace shade trees lost.

"Avoid those mile-a-minute 'miracle' trees like hybrid willows and hybrid poplars that are advertised to reach your roof height in a single season," Sternberg says.

Native trees have adapted to survive local weather conditions. "Many of them can be found in the savannas and forests of central Illinois, where their ancestors have been surviving tornadoes - and other weather extremes - for thousands of years," he said. "Among the best are the white oak types including white, bur, chinkapin, post and swamp white oaks," he said. Other native hardwoods that have stood the test of time include the hickories, hornbeams, hawthorns, black gum and walnuts.

But simply purchasing a native hardwood tree and sticking it in the ground probably isn't enough. Trees need to be properly planted and cared for.

"The catch here, with natives or any other trees, is that they need to be in good condition and well-formed," Sternberg says. "Some trees in hard-hit neighborhoods like Iles Park and Bergen Park that do not have the reputation for being strong-wooded did survive the storm, because they were in good condition and structurally sound.

"Hackberry, cottonwood, ash, catalpa, tulip tree and maples come to mind," he adds. "Just like children, raise them well and they can survive."

Evergreens often are planted for their ability to shelter dwellings from the force of winter winds. During the March 12 tornadoes, this trait worked to their disadvantage.

"There is a price to be paid for foliage," Sternberg says. "Evergreens, and those trees that retain their leaves into or through winter, offer more surface area for wind and ice to catch."

"This is why so many of the trees that failed during the tornado and the Thanksgiving ice storm (in 2004) were pines, spruces and other evergreen conifers."

Large evergreens or weak-wooded trees should not be located where they can be blown onto homes. "The distance is critical," Sternberg says. "A large tree 50 feet from your house might knock off the gutters or break a window as it falls, but a large tree 10 feet from your house could crush your bedroom with its trunk."

Trees need to get a proper start if they are to live a long life. Sternberg recommends that trees be taken out of pots and the roots gently coaxed into a radial, spokelike pattern.

Potting soil should be washed away because ground soil will wick water away from potting soil, and consequently, the new tree's roots.

He advises avoiding trees that have roots circling around the inside of the pot, a process he calls "root girdling."

"Go to the nursery and take the tree out of the pot right there," he says. "If you see roots the size of your finger circling the tree, don't buy it."

Long-term tree health begins underground. "Any tree with a healthy, expansive, unrestricted root system will fare better in a storm than any tree with a compromised root system," Sternberg says. "Tree roots extend outward well beyond the branch spread, and are most active within the top two to three feet of soil. Do not disrupt them with pavement, curb cuts, earth fill, excavation, trenching or changes in irrigation patterns, and they will hold your tree up against all but the very worst winds."

Above ground, Sternberg says, proper pruning can keep a tree growing strong. "The health of the bones and joints of your tree also are critical," he says. "Trees that broke apart in the tornado, or in the Thanksgiving ice storm a couple of years ago, often were the ones that were very hollow or had narrow angles of limb attachment."

Trees that had been topped in the past were at risk, showing damage high in the crown. "Unbalanced crowns, which react to wind by twisting like a weather vane, also are at a disadvantage," he says. "Maintain a sound structure with periodic light pruning, beginning when the tree is in its formative years, and follow proper pruning procedures to maintain well-spaced limbs set at broad angles to the erect, single trunk."

"Eliminate forks and clustered limbs before they have time to develop into problems."

An older, established tree with structural problems might need reinforcement in the form of cables and bracing to help it weather storms and prolong its life.

Sternberg says only arborists who have passed the International Society of Arboriculture certification exam should perform cabling or bracing.

Don't hire unqualified arborists to perform work on a tree you plan to keep, he says.

"If lightning exposure is a concern, that can be addressed at the same time," Sternberg says. "Trees, just like houses, can have lightning protection installed."

Sternberg says it pays to ask questions before proceeding. "If you don't know, ask someone who does," he says. "Once the storm cleanup is done and our local professional, ISA-certified arborists have time to breathe, hire one to come out and inspect your trees," he says. "Certified arborists are allowed to announce their ISA certification in their ads, or you can obtain a list by contacting the Cooperative Extension Service or the Illinois Arborists Association.

"Those trees grown properly and maintained properly have the best chance."

Homeowners should consider planting a variety of species in different sizes.

"Regarding size, I would suggest 2.5-inch (trunk diameter), 1-inch and possibly even smaller trees be planted at the same time," says Dave Bender, executive director of the INA. "This should provide the homeowner a variety of size options and give their landscape a bit of diversity."

"Not only are you planting for today, you are planting for tomorrow."

Large Shade Trees

  • Sugar maples
  • Red maples
  • Norway maples (in certain areas)

"All of these trees should be planted away from power lines and also away from the house," Bender says. "They will provide great fall color and decent growth speed."

Oaks

"I suggest the swamp white oak," he says. "The swamp is a native tree and is a fast grower and can adapt to most conditions here in central Illinois. Like most oaks, it is best to plant them in the spring."

European lindens

River birch  (single- and multistem)

"This is a great tree for instant gratification, but plant them in the proper location," Bender says.

Ornamentals

  • Serviceberries - both single-stem and multistem clumps
  • Flowering crabs
  • Hawthorns

"All of these are great trees that are a little smaller and have nice spring flowers," Bender says. "They are salt-tolerant and very disease resistant. In many instances, these can be planted closer to the house and under power lines. Give the clumps and multistems - like serviceberries - room to grow,
though."

Evergreens

  • Blue and Serbian spruce

"You can't miss with spruces," he says. Bender says the trees listed are widely available and popular with the public.

Planning
Along with plant and tree selection, homeowners must choose the right spot for planting. "Make sure that trees are not planted too close to buildings or in locations that may not serve them well in five, 10 or 20 years from now," Bender says.

If the checkbook allows, seek professional planning and installation advice. "If it is within their budget, I strongly recommend they utilize a professional," Bender says. "It may cost a couple hundred bucks, but in the long term, it could pay off."

Planting
Experts have pointed to downed trees that were planted too deep. Bender says even plant nurseries sometimes plant too deep.

Conventional wisdom is to plant the tree in an 8- to 10-inch "dish," not a hole. The top few inches of potting soil can be shaved off in order to get more oxygen to the roots.

"Roots crave oxygen even more than they crave water," Bender says. When roots search for oxygen, they actually may grow upward."

"That's what causes root girdling," Bender says. He says landscape professionals can be sure the trees to be planted are not root girdled. The tree-planting window remains open until temperatures consistently reach the 70s.

Go easy on the mulch.

"There's a thing called volcano mulch, and it's horrible," Bender says. Too much mulch can harbor disease and make things too hot. A good 2 to 3 inches of mulch is plenty."

Chris Young can be reached at 788-1528 or chris.young@sj-r.com

 

 

 

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