Frequently Asked Questions

 

Click on each question to expand its corresponding answer.

How can I avoid transplant shock when planting an oak tree?

Planting a tree is like making an investment. A maple tree is like a dotcom stock – it goes up really fast. An oak is more like a government bond, slow to mature but solid as the earth.

Although they’re slower getting to the payoff, oaks make up for it by developing into commanding trees. They look good up close, where you can appreciate their lobed leaves and ridged bark, and from a distance, standing together in a natural grove or spreading their broad arms above a billowing prairie.

Particularly in the fall, when their leaves go various shades of red, orange and russet, oaks are the most glorious trees in our local landscape. They’re our Plant of the Month for October.

“None of the big maples and the rest have the size and majestic shape our oaks have,” says Connor Shaw, who owns the Monee tree nursery Possibility Place. “And there’s nostalgia associated with oaks. You think of oak furniture and acorns. They’re historic trees.”

If they’re so great, how come oaks are so hard to get going in home landscapes? Shaw and Cliff Miller, head of the Lake Bluff landscape design firm P. Clifford Miller, both say it’s because we try to hurry oaks along.

Homeowners often want an instant landscape, so they pay for big oaks. But oaks’ roots are more delicate than those of many other trees and they don’t take transplanting easily. Miller says the stress of the transplant can lead to dieback and bug infestations – and even slower initial growth than the tree could have had.

The simplest way to avoid transplant stress, Miller and Shaw agree, is to start with small oaks. Their root balls are so small that they’re far less likely to be damaged in transplanting, and if any recovery time is needed, it’s short. Besides, both oak experts say, and oak planted small will eventually get bigger than one planted big, because of its low-stress youth.

Shaw suggests starting with oaks whose trunks are 1 1/2 to 2 inches in diameter; that’s about 6 to 8 feet high, and priced from $100 to $250.

The usual slam on oaks is that they grow too slowly, but Terry McLoughlin, an arborist who owns McLoughlin Tree Care in St. Charles, says, “They grow just fine if you put them where they want to be.” Annual growth of a foot or more is normal for well-handled oaks after their first year in the ground, Shaw says.

The essential way to avoid stressing an oak is to plant it in the right conditions. Most must be grown in full sun. Here are some of the best oaks for Chicago-area yards:

White oak (Quercus alba) is the Illinois state tree. Its leaves have deep round lobes and go a rich burgundy in fall. A white oak can top out at about 80 feet high. It must be grown in moist soil. Miller says white oaks are finicky in one important way: They need relatively acidic soil. If your soil pH is above 7, don’t plant a white oak. Miller recommends a chinkapin oak (Quercus muehlenbergii) as a substitute in those more alkaline soils.

Swamp white oak (Quercus bicolor) is true to its name. It can’t take a dry setting. “If you have a seasonally wet depression in your yard, you want a swamp white,” Miller says. The leaves aren’t very lobed, but they go nice shades of orange in the fall. Swamp white oak can get to 60 feet high and wide, and, according to studies at The Morton Arboretum can tolerate urban conditions well. It prefers slightly acidic soil but isn’t as picky as the white oak. An added attraction on swamp whites, which hail from a little south of here: “They have very cool peeling bark, almost like the river birch, that everybody loves,” Miller says.

Bur oak (Quercus macrocarpa) is among the slowest-growing oaks, but when it gets where it’s going – up to 80 feet high and 90 feet wide – it's incomparably statuesque. With deeply grooved bark and asymmetrically outstretched branches, an old bur oak is an amazing sight. It’s the variety that adapts to a wider range of conditions than most local oaks, Shaw says. “It can sit on a hill or in a floodplain and do fine,” he says. Miller recommends bur oaks for planting in the poor, disturbed soil of new subdivisions. “They’re a pioneer tree,” he says. “They’ll love it.”

Pin oak (Quercus palustris) is loved for growing faster than other oaks and for its pointy, slim-waisted leaves to go deep reds and browns in fall. But McLoughlin believes homeowners often love it the wrong way. “They like it so much they stick it in the front yard,” where drainage has usually been engineered to drain water off the flat lawn, he says. Pin oaks can grow tall – up to 70 feet high and 35 feet wide – if given abundant water, but in drier sites such as lawns, most are forgotten and die young, he says. McLoughlin recommends planting pin oaks in depressions where water collects.

Red oak or northern red oak (Quercus rubra) is the only one among these oaks that can take any shade – although light shade only, not the darkness below Norway maples. It’s a fast grower, eventually hitting about 75 fee high and 65 feet wide if planted in an acidic soil. The fat, pointy leaves go yellow and occasionally red in fall. McLoughlin warns, though, that red oak is the variety that most often has to be removed because of rotting inside.

By Dennis Rodkin, Chicago Tribune, October 1, 2000

How can I reduce the maintenance time with my trees?

Some days it seems like we are living in a mad and crazy world. Business people say that we are becoming more and more efficient.

I believe we are becoming more efficient; however, for us to be more efficient it seems like we must work longer hours.

Maintenance is critical to plant survival. Having fewer free hours means less time to manage your landscape. I know I run counter-culture when I say smaller is better and timing is everything versus bigger is better and I want it now. Here are a few things I have learned while being in the trenches for 25 years.

Plant a 1.5-inch caliper tree next to a 4-inch caliper tree, and in four years the trees will be the same height and crown size. This is only true if you take the time to maintain the two trees. The 1.5-inch tree needs to be mulched and watered the first growing season. Watering is only necessary during drought for the following year. The larger tree must be watered every week during the growing season for four years and mulched. If you have the ample resources of time, dedication to watering, and money, then the large tree is possible. If your resources are limited, get the smaller tree, and it will be the same size as the bigger tree would be in four years.

Another thing to keep in mind is that smaller trees come with small root balls and weigh as little as 50 to 150 pounds; whereas, a 4 inch caliper tree root ball weighs about 1400 pounds. Smaller trees cost less to install and give the option for some people to install their own.

There are a few important recommendations for planting your own tree. The hole should be shallow enough so that the top of the root ball is 2 inches above grade. The hole should be about 2.5 times the width of the root ball. After filling the hole, surround the perimeter of the backfilled area with a 3-inch high berm. This area creates a “saucer” which can assist in watering, and should be filled with 3-inch deep mulch.

Correct watering techniques are very hard to teach. If we do not get a 2-inch rain once a week during the growing season, you must water woody plants in order to get them established. More frequent watering may be required if the plants are in gravel or sandy sites, and if we have temperatures in the 90’s with no rain. Once the woody plants are established, we really don’t need to water unless we have a drought for 3 or 4 weeks.

Quantity of watering is always difficult, but I prefer to saturate the ball by filling the “saucer” twice. Many people have irrigation systems that treat grass, woody plants, and perennials the same. They are not, and require different zones for different watering regimens.

Keep in mind that one can only reduce long term maintenance if one chooses the right plant for the site.

Is there a plant that does not attract insects?

There is no such thing as an insect free plant. Every year I give numerous talks and invariably get asked many questions. One question that people frequently ask is, “Will I have more problems with insects if I install native plants in my landscape?” There is no such thing as an insect-free plant. However, you might believe that it is possible to have an insect-free world through pesticides. At least that is what the pesticide companies would like you to believe! Actually pesticides may create more problems then they solve by killing the good insects (98%) as well as the bad (2%). The other factor of environmental harm could be debated long and hard.

We have not used an insecticide, miticide, or a fungicide in 16 years. You might draw the conclusion that we don’t have insect problems because we grow native plants. That would be the wrong conclusion. One reason we do not have problems is that the method we use to raise our trees and shrubs dramatically reduces stress, which in turn reduces insect problems. Another reason is that we are willing to accept a certain amount of damage such as holes in leaves, gall (there are 400 gall that live on oaks and do not seem to do damage), and an occasional defoliation of one or two trees. This does not mean we will never spray an insecticide, but we will try hard not to!

Another reason we don’t use insecticides is BUTTERFLIES. As hard as it is to believe butterflies ARE insects and insecticides definitely kill them.

To attract butterflies you must raise plants that are sources of larval food for the caterpillar and nectar sources for the butterfly. Butterflies seem to gather nectar from a large number of plants. Larva tend to be very specific, and their chosen plants are mostly native. For example, the zebra swallowtail lays its eggs only on Asimina triloba (Paw Paw).

“If I grow these butterfly plants will they come?” Upon visiting the greenhouse last spring in the evening, I noticed the Bladdernut (Staphylea trifolia) were in bloom. Upon shining the flashlight into the plants, I was greeted by 50 to 100 moths that were pollinating the plants. We asked an entomologist how the moths found our plants since the closest bladdernut we know of are four miles away. He said, “They blew in!” Fifty to one hundred moths pinpointed these shrubs in the middle of nowhere. There must be an unbelievably potent pheromone involved that I want to bottle and sell! So, will they come?

They came! Lorrie, our propagator, informed me that we had a critter eating the sassafras and the spicebush. Together we set out to find this critter, and it turned out to be a caterpillar with two fake eyes -- the spicebush caterpillar. The nearest spicebush or sassafras is twenty miles away. We will continue to watch the host plants for caterpillars and see what shows up.

What happens if a tree is planted too deeply?

Trees planted too deeply die prematurely. One reason is that roots need oxygen. A second reason is that roots can actually choke the tree. Many people believe that any circling root is bad. This does not appear to be true. The worst circling roots are those that circle at or above the root collar or root flare of the tree. Roots that circle below the root flare are usually not problematic. We recommend planting 2-inches above grade, or higher than 2-inches if planting on a wet site.

What are your root-bag planting specs?

Here are our specs, also outlined in our annual catalog:

  • Hole width should be about one foot wider than the ball, and 10"–12" deep. If you are planting with an auger, the 30" is a suitable size.
  • The planting of the root-bag material requires that all ball covering material be removed from the ball before planting. This includes the removal of all rope, burlap, nylon bag and “cap” (white nylon on the bottom of the ball).
  • If the root-flare is not visible at the soil's surface, then a light shaving of the soil from the top of the ball is needed. This is done by using a shovel to remove the top inch or so of soil with a very light hand.
  • When the tree (or shrub) is placed in the hole, the top of the ball should rest 1 to 2 inches above the surface of the surrounding soil before the hole is filled. The ball with settle down into the hole on its own. This is to prevent it from being planted too deep.
  • Mulch should be spread around the tree (or shrub) in a ring that is 3 feet in diameter and 2 to 3 inches deep. Be sure that the mulch is evenly spread and avoid donuts and volcanoes. We recommend coarse mulch or wood chips; they work best and are usually easiest to find.
  • Watering is essential. After the plant is in the ground, it should be watered in, about 5 gallons; do this twice. After that, water 10–15 gallons a week for every week we don't get an inch of rain. Do this over the next 8 to 12 weeks during the growing season.