Proper care will grow homeowners' tallest assets

Local tree experts shake their heads when they hear about a homeowner removing a perfectly healthy tree simply because of a fear it may potentially come falling down in a big storm sometime in the future.

The benefits of trees far outweigh their risks, say two local tree experts: Jim Glazebrook, a certified arborist with The Davey Tree Expert Co.'s northeast Illinois office in Wheeling, and Sandy Clark, forestry/grounds superintendent for the village of Mount Prospect.

“Trees are a big asset. They shade and cool the home, add value to the property and add oxygen to the atmosphere,” Glazebrook said.

Before cutting a tree down, carefully consider the alternatives, the U.S. Department of Agriculture Forest Service advises in printed materials. “The effects of removing a tree are often pronounced in landscape situations and may result in reduced property values. Tree removal should be considered as the final option and used only when … other … corrective actions will not work.”

The key to enjoying trees that are safe, beautiful and beneficial to the environment is practicing careful maintenance throughout a tree's life. You cannot just plant it and forget it except for occasional watering, Glazebrook and Clark agree.

Choosing the right tree for the right place is key. If you have the luxury of planting your own trees, make sure you choose a good variety of disease-resistant trees and do not plant multiples of the same variety, Clark says.

Mixing it up gives you a measure of protection against some future tree disease or insect that may invade and it also gives you a nice variety of colors and shapes in your yard, Glazebrook adds.

Proper planting comes next. Make sure you don't plant a tall-growing tree near power lines, for instance. Smaller varieties recommended for these areas by ComEd include serviceberry, eastern redbud, Japanese tree lilac, amur maple, Susan magnolia, Japanese red maple, pagoda dogwood, hawthorn and flowering crabapple. None of these will grow too high. They are also beautiful and hardy.

Those species the power company strongly recommends against planting anywhere near power lines are the silver maple, Norway maple, sugar maple, sycamore, ash, honey locust, willow, linden, spruce, pine, Bradford pear and oak.

No matter what you are planting, be cognizant of how big it is expected to grow. Make sure you space your trees based on what you expect their mature height to be, not based on their size at the time of planting. Professionals can help you with these decisions.

When a tree is newly planted, be sure to water it regularly. The younger the tree, the more careful watering it demands in order to take root and thrive, Clark and Glazebrook say.

It is also very important to have your trees trimmed and pruned by someone who knows what they are doing every year or two, especially when they are young.

“You want to start with structural pruning when a tree is young so it has a strong structure when it is mature,” Clark said. “A good arborist will select the strongest branches and will weed out ones they can tell will become weak in the future.

“If you know what to cut, you can do it yourself when a tree is young and we have a great brochure on that from Tree City USA,” she said. “You want to make sure the branches are evenly spaced; growing at the correct angles; are not rubbing against one another, etc. You also want to remove the suckers (smaller branches) growing at the bottom.”

But there is definitely an art to pruning. Hiring a certified arborist who has been trained is best, especially with well-established trees, Clark said.

Glazebrook and his district manager, John Drescher, concurred.

“A tree in full leaf is like a sail in the way it catches the wind. You want to open up the canopy so there is less resistance to the wind,” Glazebrook said.

“Of course, when you get to winds of 60 miles per hour or more, and wind shear, there are no guarantees with any tree,” Drescher said. “But it you have had your trees on a regular pruning program, problem branches will have already been removed and you are giving yourself the best chance for a good outcome.”

Cost depends on the size of the trees, varieties and location. The best thing to do, Clark suggests, is to get two or three tree-trimming estimates from companies who employ certified arborists, recognized by the International Society of Arborculture. The tree companies should also be members of the Tree Care Industry Association.

Make sure to ask for the companies' certificates of insurance so that you cannot be held liable for any injuries that might occur and make sure the quote includes branch disposal. And if you are removing a tree, ask if stump removal is included in the quote.

Clark said she is willing to give her residents the names of firms the village of Mount Prospect has successfully used in the past. But she cannot recommend firms. She assumes other municipalities have similar policies.

Drescher also emphasized that homeowners should investigate the companies they are calling. Know their reputation, depth of experience and history.

“There are lots of certified arborists out there and some are better than others. Check into their expertise and the level of service they offer,” he said.

The fertilizing of trees is generally not necessary, Clark said. Naturally-occurring soil nutrients are usually sufficient to sustain a tree. But there are some exceptions, like pin oaks that require a high-pH (acidic) soil, and a few others. You may need to offer those varieties some added help.

“We only suggest fertilizers on a case-by-case basis,” Drescher said. “They can be administered through injection or through surface applications. But we usually just suggest organic mulching.”

Mulching is very beneficial to trees, as long as it is done correctly. It can reduce water loss from the soil, aerate it and add nutrients. Mulch also insulates the soil from cold in the winter and heat in the summer. Interestingly, it also keeps people from getting too close with lawn mowers and weed whackers, which can cause major damage to tree trunks.

But mulch that is piled too deep and too close to the tree can also be a problem.

“You don't want the mulch to actually touch the tree trunk and root crown. That can cause fungal growth,” Clark said. “Instead, you want three to four inches deep of wood chips as far out under the tree as you can tolerate.”

“Trees need lots of both air and water, so don't let the mulch become too compacted,” Drescher said.

When it comes to well-established trees during a drought, Clark suggested watering them 1 inch every seven to 10 days, using a sprinkler or a soaker hose and making sure it covers all the way to the edge of the tree's drip line (where the branches end). You can ascertain when you have given a tree an inch of water by putting out a tuna can and when it is full, you are done, she said.

If we have had average rainfall, no watering is needed at all. But if you see your turf start to go dormant, start watering your trees, Drescher said.

Other hazards to watch for with your trees include dead branches, cavities or rotten wood, cracks or slits in the trunk, damaged roots and mushrooms at the tree base. Is the tree strongly leaning to one side? That is another danger sign.

The biggest problem currently, of course, is insect infestation from the Emerald Ash Borer.

“We are seeing lots of success stories with the ash trees when people are proactive and they have the tree treated early,” Drescher said. “But you have to keep up with the triage program and have your trees treated every two years until it is deemed safe by a professional. Don't get a false sense of security from our cold winter. We don't know if the frigid temperatures killed off the Emerald Ash Borer larvae or not.”

Clark agreed. “The treatments are good, as long as you keep up with them. We selected our 800 best ash trees in Mount Prospect and have been treating them.”

Identifying other weaknesses in a tree can be tricky, she continued.

If there is a split through a tree, you should probably have an arborist assess it, especially if it is overhanging a driveway, sidewalk or patio.

Shallow roots, on the other hand, are not a problem, according to both Clark and Glazebrook. Local soil has a high clay content that encourages root growth close to the surface. In addition, the larger the tree grows, the more shade there is that causes the turf to become depleted, exposing the roots. In addition, maples and some other varieties of trees just naturally develop shallow roots. So don't lose sleep over a large tree with shallow roots. They are not a common cause of tree failure, Drescher said.

Trees that are leaning are also not necessarily a problem. Some trees naturally lean, Clark says. But if you suddenly notice that the soil around the leaning tree is gapping and breaking, consult an arborist.

Pruning season

• How often: Beginning 2 years after planting, prune lightly every year or every other year. After 10 years, frequency of pruning depends on the type of tree and amount of shade the canopy receives.

• When to prune: Winter is best time of year to prune because branches are easy to see, diseases cannot be spread, and there is minimal stress to the tree. But for most trees, pruning can be done at any time. Exceptions are trees that are prone to fire blight or oak wilt.

• Watch out for: Do not remove more than 25 percent of the tree's live branches (and therefore leaves) at any one time.

Source: Tree Owner's Manual, U.S. Forest Service