This past spring I planted a lacebark pine (Pinus bungeana) in full sun. As winter began, the angle of the sun’s rays has caused the tree to receive, at most, 4 hours of sun. What are sun requirements of evergreens in winter?
In general, pines adapt to the winter weather by becoming dormant, says Susan Eyre, Rich’s Foxwillow Pines Nursery, Woodstock. It is the freeze and thaw cycle that is hard on a plant, not the loss of sun hours. In a January thaw, sap rises and then freezes, which can cause the bark to crack, but plants usually recover.
Is it possible to plant and grow Italian cypress in the Chicago area? Are our winters too severe for it? If they are, is there an alternative conifer that will provide a similar look?
Italian cypress (Cupressus sempervirens) has dark green foliage and horizontal branches and grows into a dense column 60 feet high in Italy. It is not hardy here.
Paul Jeffers, tree and shrub salesperson, Gethsemane Garden Center, Chicago, suggests substituting a dense, columnar arborvitae, (Thuja occidentalis ‘Fastigiata’). It grows to 25 feet tall and 5 feet wide, but can be kept lower by pruning. The very narrow arborvitae ‘DeGroots Spire’ is another choice. The false cypress Chamaecyparis nootkatensis ‘Green Arrow’, often mistaken for arborvitae, is a tight upright growing plant.
I have a nicely sheltered, rounded 7-foot tall Japanese red maple on the southeast corner of my backyard. Half of the tree has lost its leaves, the formerly red bark is turning gray, and a good-sized square of bark has been stripped off on the side that faces the yard. I sprayed the exposed bark with black pruning spray to close any entry for insects. I have not cut off any of the branches.
Does the winter have any effect on the tree? Should I look for some insect infestation? What should I do now?
“It appears that the tree suffered some kind of injury. Over winter, watch for sun scald on the southern exposure. Use paper tree wrap on the trunk,” advises Mike Geimer, owner of Geimer Greenhouse, Long Grove. If you are fearful of insects, you can use an organic pyrethrum spray. Black pruning spray is not necessary.
I’m moving to a townhouse with limited direct sunlight. I would like to put a Japanese maple in a north-facing garden but don’t know if it will do well. What are the best kinds? Also, when is the best time to plant a small tree?
Japanese maples are small decorative trees which are becoming more popular as more dependable cultivars come on the market. Even so, an established tree will sometimes succumb in a severe winter. Their light requirements vary.
The trees can grow in a northeast exposure, and 6 hours of sunlight is not too much, according to Jeff Sibley, nursery manager of Red’s Garden Center, Northbrook. They need a moist, well drained, neutral soil, amended with organic matter. They can grow to 8 feet tall in a good location. He says the best planting time is right after Mother’s Day. A protected spot and plenty of moisture are critical elements for survival, even with the newer cultivars.
Sibley recommended the following cultivars of Acer palmatum var. dissectum, a cut-leaf variety, as the most graceful trees:
My split-leaf Japanese maple tree is 15 to 20 years old, about 7 feet high and about 10 feet wide. It is overtaking the corner of the yard. Can I trim it, and at what time of the year?
Trim your tree in late fall to early winter when the tree is dormant. Remove only one-third of the amount you want pruned each year, being careful to retain all its charm.
“Go easy on it,” says Joann Madon, horticulturist, The Growing Place, Aurora and Naperville.
I have two 20-year-old pine trees whose needles are turning brown on the west side of the plants. On the east side I have a compost pile.
I live in the St. Charles region and my soil is mostly clay. What is causing the browning? Should I get rid of the compost? How do I correct the damage?
Climate conditions could be the cause of the brown needles. There was strong west wind this past winter season, which caused winter burn. With last fall’s rain and winter snow cover, the soil never dried out. According to Todd Mohr, sales associate, Rich’s Foxwillow Pines Nursery, Woodstock, pines normally begin
to go dormant in late August. “We had a lot of burn on our evergreens which showed up over summer,” says Mohr.
Cut a sample of the branch and make sure the plant is alive. You can photograph your tree or take the sample to an arboretum or garden center for evaluation. The compost should not affect the trees unless you have a large pile that is prohibiting air circulation. Spread the compost loosely over the area.
White pine is a native Illinois tree. It may come back on its own. If not, have a tree professional diagnose it.
I have lost four 12-15 foot tall white pine trees over the last year. All had the same symptoms, browning needles at the bottom that continued up to the top. Can you tell me what pest is killing the white pines? I am also losing an Austrian pine now. It is experiencing the same symptoms.
White pines in this area are very rarely troubled by disease. They are, unfortunately, highly susceptible to high pH problems, or soil alkalinity, and are utterly intolerant of salt, according to Rich Eyre of Foxwillow Pines, Woodstock. The browning needles could also indicate the plant is getting too much water or has poor drainage.If environmental problems are not the issue for your white pines, consult an expert. Betty Lockwood, Plant Information Specialist at the Chicago Botanic Garden, suggested you bring them a sample branch to check on disease and bring in an arborist for an on site visit to check your growing conditions. Or take a 12-inch sample of an affected tree to your local extension office.Austrian pine is very tolerant of environmental conditions but is prone to certain diseases—diplodia tip blight and dothistroma needle blight, both caused by a fungus. Only an arborist or a laboratory can provide an accurate diagnosis. If you bring in a 12-inch sample for diagnosis, be sure to sterilize your pruning shears with denatured alcohol after cutting the diseased wood.
What is the largest tree that one can plant? We are trying to replace some 7- to 8-foot trees that were recently destroyed.
Trees sold at garden centers that are 2.5 to 3 feet tall, with a 2.5 inch diameter trunk, can be planted by hand. A hole for a ‘balled and burlap’ tree with a 5 to 6-inch diameter trunk can be dug by hand without a tree spade.
Any tree with a trunk larger than 6 inches in diameter would need a tree spade to do the moving and digging. Even large trees, such as a 35-foot tall tree with a trunk 9 or 10 inches in diameter can be transplanted with proper equipment. “Spruces 30 feet tall can be installed easily with a tree spade,” according to Greg Oltman, owner, Gro Horticultural Enterprises, Huntley.
I’d like to plant a white bark birch in front of my home in my sunny front yard. What can you tell me about Betula utilis var. Jacquemontii?
The birch, Betula utilis var. Jacquemontii is a tall, narrow tree (to 100 feet) with very white bark that’s native to India. It is subject to borers. The popular weeping white bark birch, B. pendula is also subject to borers in our climate and is not a suitable choice.
“There are better birch choices, so choose what grows well in our area,” advises Ken Morris, vice president of Spring Bluff Nursery in Sugar Grove. Two trees resistant to borers are the paper or canoe birch and the river birch.
Canoe or paper birch (B. papyrifera) has a stout trunk with creamy white bark that peels off in papery layers. It is native to North America. It is the first paper birch bred to resist the bronze birch borer, but it still needs to be monitored and sprayed yearly for the borers. A good cultivar is ‘Renaissance Reflection.’
River birch (B. nigra), native to the eastern United States, is fast growing when young. It can reach more than 50 feet in height. Its bark is a smooth, shiny apricot and, when mature, flakes and curls in cinnamon strips. It tolerates slow drainage and is also resistant to borers. “It’s pretty tough, good and sturdy,” says Morris.
The cultivar ‘Heritage’ was introduced to much acclaim around 15 years ago.
Birch trees need moisture. Do not allow your tree to dry out in your sunny site.
What is the correct distance from my house to plant a tree? What is the correct distance from the lot line to plant a tree?
It depends on the size of the tree you are planting. A small tree such as a serviceberry (Amelanchier) or a dwarf flowering crab could be planted as close as four to five feet from the house. For a birch tree, a distance of six to eight feet would be the minimum.
Distance from the lot line does not matter as long as it doesn’t interfere with power or sewer lines. You should check with your village before planting. Closeness to the neighbor’s lot line is not an issue, because neighbors have the right to trim back any overhanging branches, according to Matt Zerby, partner in Wasco Nursery, St. Charles.
I am going to be planting five dwarf fruit trees; two ‘Bartlett’ pears, one ‘Cresthaven’ peach, and two ‘Honeycrisp’ apples. Could you give me some feedback on them?
I start ‘Dragon Wing’ begonia from seed under grow lights. What other begonias can I use to cross-pollinate with the ‘Dragon Wing’ so I can collect my own seeds?
At the end of every winter, there are many shrubs growing along sidewalks that are dead and damaged either by salt, wind or dogs. Are there any shrubs that I can plant in these more exposed situations and expect them to survive?