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Published May 27, 2011, 12:00 AM

Hortiscope: Certified arborist can selectively prune tree

Q: I have a friend who has a river birch planted very close to the front of her house. One of the branches is hanging over the house all the way to the back.

By: Don Kinzler, INFORUM

Q: I have a friend who has a river birch planted very close to the front of her house. One of the branches is hanging over the house all the way to the back. My friend’s husband wants the tree gone before it causes damage to the house. However, my friend loves the tree and does not want it cut down. Can a river birch be topped without killing it? Is it wise to do this? (email reference)

A: Absolutely not to the topping question, but yes to the selective pruning to remove potentially hazardous branches. Get an International Society of Arboriculture (ISA) certified arborist to do the work. To find the companies or individuals who are ISA certified, go to Be sure to check credentials and ask for references before allowing any major work.

Q: I’ve enclosed some pictures of an apple tree that I’m concerned about. The tree is more than 30 years old. It was a lab project by a friend who was a horticulture major at NDSU. In the lab, she grafted various trees onto crabapple roots. She gave us a Haraldson apple and a flowering crab. Both have done very well through the years. The Haraldson has produced many apples. Both trees are planted on the north side of our house and are protected by a tree grove on the north and west side of the house. Since we have a ranch style house, the trees get sunshine most of the day. About three years ago, we cut down a box elder tree that was overshadowing the east side of the apple tree. After cutting down the box elder, we noticed the apple tree had very few live branches on the side that had been facing the box elder. Since then, it has produced no apples. Last year, there were a couple of small apples but they fell off before they could mature. Last fall after the first snowfall, I noticed white growths on the trunk. The bark also has split in several places. Is this tree salvageable or are we going to lose it? (email reference)

A: I hate being a bearer of bad news, but I have no choice in this matter. The tree is a goner and there is nothing you can do to save it. You are better off planning to use if for firewood or to make wood ornaments out of any sound wood you find after the tree is cut down. Be happy that you were able to get such phenomenal service out of the tree for so many years. It has gone way beyond normal life expectations for a backyard apple tree. Sorry to give you this bad news.

Q: I’ve been square foot gardening for about 10 years. I love it and never would go back to row gardening. When I started, I used a combination of peat moss and city compost. It was loamy and fertile. I was able to pull sprouting weeds with two fingers. In the fall, I would clean up all the remains and put about a bag of leaves on each square. In the spring, I would turn the soil and begin planting. As time passed, my soil became very hard. I’ve added peat moss and compost, plus some perlite, but that didn’t work. Pulling weeds requires a small spade. I think I need sand to help make it loamier. What do you recommend? If you do suggest adding sand, how much and what type of sand? Do you find it at a local landscaping business or will any sand do? Thank you for your advice. (email reference)

A: Apparently, there is more clay in your soil profile than you thought. The organic matter additions that you have been making are not a permanent solution because it continues to break down through time. However, it still is a good idea to add copious amounts of sphagnum peat to keep the soil loose. Adding sand is a tricky operation. You want to use coarse, not fine, sand. Garden center outlets might carry the right sand for you to use. The important issue is mixing the sand with the soil. We’ve found that adding coarse, screened sand to the soil and attempting to work it in with a shovel or a tiller just doesn’t do an adequate job. Pockets of sand will exist that will give you inconsistent drainage characteristics. What does work is the use of a portable concrete mixer. For every shovelful of soil from your garden, add at least seven to eight shovels of sand, along with some of the peat moss. Mix for about five minutes or until everything is homogenous in texture. A handful taken from the mixer should show a uniform particle distribution of the various components. Give it another test to be sure by placing some of the mixture in a free-draining container and adding water. It should drain the same way water percolates through coffee grounds. I know this isn’t something that generates enthusiasm to do, so I’d suggest attempting to soften everything up with sphagnum peat moss first. Work it into the soil as best you can using a shovel or tiller. If that doesn’t work, then give the more onerous suggestion a consideration. Gardening should be fun, not miserable work.

Q: I bought a pot with seven tulip flowers in it. I have no idea how to take care of them and where to put the pot. Should I keep it in the house or put it outside? Please give me the answers as soon as possible. Thank you for your help. (email reference)

A: Keep the soil moist for now. At bedtime, if you can, move the pot to the coolest spot in your dwelling and then back to the viewing location when you get up the next day. Once the flowers fade and the petals fall off, prune the flower stem. However, allow the foliage to remain and move the pot outdoors where it can get more sunlight. Allow it to stay this way and keep it watered until the foliage turns yellow. After that, carefully pull the foliage off and discard it. Allow the soil to dry and then take the soil and bulbs out of the pot. Find some place to plant them outdoors for blooming next spring. Enjoy!

Q: Is there a difference between trailing and wave petunias? I say yes, while my friend says no. Who is right? Thanks! (email reference)

A: Trailing petunias existed long before wave petunias were even a genetic thought. The difference is in their vigor and blooming potential. Wave petunias are tough plants. They have been eaten by rabbits and grown back. A single plant has the ability to spread and cover a 4- by 4-foot area in a growing season.

To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or e-mail