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Ron Smith answers reader's questions about the world of plants and gardening.

By Ronald C. Smith, Horticulturist

NDSU Extension Service

Q: I own a farm in Peterborough, Ont., which is northeast of Toronto. It was a wheat farm, but it has been dormant for 15 years. Since the land was dormant, birch trees have taken over. The trees are 20 to 25 feet tall. There are many clumps with three to four trees. Do you think that these trees could be transported and sold at nurseries using the right tree spade? I'm thinking of purchasing a tree spade to transplant these trees. (e-mail reference)

A: I would suggest finding out if there is a market for the trees and what price you could charge. You will need to set limits on the distance and time of year to move them. You also will need to determine ease of access to the properties where they are to be moved and what kind of guarantee you will provide. You should root prune the marketable trees for at least a year prior to moving them. You didn't say whether or not you've had horticulture experience or education. You need to figure what the cost and maintenance of the spade will be and how many years of service you can get out of it. In addition, you need to find out how many trees you will have to move to recoup your cost of investment and return a profit. I encourage you to do extensive homework before tackling this venture because you don't want to come out on the short end of the financial stick!

Q: My beautiful Norfolk pine is approximately 10 years old. The tree is starting to lose its lower branches. I would like to transplant it outside. The tree would get southwestern exposure for seven months of the year. Where I would like to plant the tree has two walls to protect the tree. What temperatures are bad for Norfolk pine? Is there a possibility of it growing and flourishing outside? I live in Ohio. (e-mail reference)

A: Norfolk Island pine is a tropical plant. Any temperatures approaching the freezing point would kill it. There is no chance it would thrive in any outdoor Ohio environment. This plant is easily air-layered, so you may want to start over to raise a more compact and bushy plant. Go to my Web site at for more information.

Q: I believe my dogwood is not coming back to life this year because there are ants in the soil. Do you have any suggestions to help me? (e-mail reference)

A: I don't have an answer based on the information you gave me. However, I can almost assure you that the ants are not the direct cause of your problem.

Q: I have a pin oak that was damaged by repeated spraying with a water sprinkler. The bark is peeling off and the wood is rotted on the damaged side. The tree looks healthy otherwise. Can I do anything to save this tree or should I cut it down? I would like to save the tree. (e-mail reference)

A: The best advice I can give you is to seek out the assistance of a certified arborist in your community. Tell the arborist up front that you would like to have the tree saved if possible. It is too easy and fast to cut down a tree. If the tree doesn't pose a hazard, then every effort should be made to save it.

Q: I know you've had hundreds of questions concerning apple scab. I have two flowering crabs that are just starting to grow leaves. Should I spray with Captan now? Is it too late to apply lime sulfur? (e-mail reference)

A: If the leaves have begun opening, then it is too late for lime sulfur to be used. Go for the Captan or other labeled protective fungicides.

Q: For many years, we have had an abundance of apples with worms in them. This makes the apples inedible. What should we be doing to get rid of the worms? (Mooreton, N.D.)

A: Spray using an insecticide, such as Sevin, at blossom drop and again in 10 to14 days. Spraying two more times after that should do the trick. You can try pheromone traps, if you can locate them. Put two or three traps in the larger trees. Picking up the apples that drop to the ground in the fall goes a long way in breaking the infestation cycle.

Q: I have a hosta plant that has grown too large. Is it possible to divide the plant and replant one of the halves without damaging it? (e-mail reference)

A: Dividing anything causes some damage. However, hosta is a tough customer because it is a member of the lily family. Hosta can be divided using a straightedge shovel. Do it now before new growth commences.

Q: I planted a row of evergreens under some power lines about 20 years ago. The trees are about half way from touching the lines, which is a safe distance for trimming. I read that spring is a good time to cut off the leader. This should slow down growth and get the trees to start bushing out. Should I wait until new growth starts before cutting off the leader or should I trim now while they are still dormant? How much of the leader should I cut off, but still have the trees look good? (e-mail reference)

A: I assume you are writing from somewhere in the northern part of the U.S. because you say the evergreens are dormant. Cutting the leader back will result in a bushier plant. I would suggest cutting out less than you think you should. You can go back and trim more if you don't get the results you want. Now would be a perfect time to do the trimming.

Q: I have a crab tree in my yard that has two low branches that appear to be suckers or water sprouts (not sure of the difference). They do not look like normal branches because they come out and grow very close to the trunk. I know I should have dealt with this problem years ago, but what do I do now? Should I cut them off as close to the trunk as I can or leave them alone? (e-mail reference)

A: After you get done reading this, go out and cut those growths back flush to the trunk. I know of no reason why they should be left as is.

Q: We moved into a new home with a small dogwood tree in the backyard. The tree was planted by the previous owners along the south side of a north-facing fence that receives the full brunt of heat and sun during the summer months. Last summer it was very dry, so the leaves curled, dried and fell off. Can I transplant the tree to a shadier area on the north side of the house this spring or do I need to wait until after the first frost? (e-mail reference)

A: If the tree is dormant at this stage, transplant it. Wait if the tree is not dormant. Try to keep the tree's root system moist (not soggy) and cool by using an organic mulch.

Q: I have three flowering cherry trees in my yard that were blooming when we planted them more than a year ago. We were very disappointed after none of the trees bloomed this year. We would like to do whatever we can to encourage blooming next year. Any idea why a cherry tree wouldn't bloom and how we might encourage bloom next year? (Bishop, Ga.)

A: Cherry blossoms are separate from the leaf buds, which makes the blossoms more vulnerable to unexpected swings in the weather. Your region of the country could have had an early warming spell that dehardened the buds enough that it killed the flowers when the next cold snap arrived. Apple trees have a mixed bud, which means the leaves surround the apple blossom. This gives them a little more protection and are less vulnerable to becoming prematurely dehardened. About the best thing you can do for next year is to not overfertilize or overwater. Allow the trees to go into winter in a tough, hardened state. This may be enough to keep the buds from being so vulnerable to shifts in spring temperatures next year, so you might get the blooms and fruit you want.

Q: A friend brought me a handful of almond blossoms. We put them in a vase with water and put them in a sunny window. The blossoms are now growing leaves! Can I use these as starts for new plants? I cannot see any roots growing from the ends of the cuttings. Can I put them in rooting material? (e-mail reference)

A: Unfortunately, almond branches do not lend themselves to propagation through cutting. They are grown from seedlings. Trees with desirable characteristics are grafted onto year-old stock. The leafing you witnessed is normal, but lends nothing to the branch's ability to form roots. Sorry!

Q: I have looked through the vegetable/fruit section, as well as the houseplant section of your Web site, but didn't see anything about starting pineapples. How hard is it to start a pineapple crown? (e-mail reference)

A: About as hard as eating freshly baked chocolate chip cookies! To start, purchase a fresh pineapple. Twist off the vegetative growth and allow it to cure on the counter for two days. Stick the vegetative stem into a well-drained, pasteurized soil mix. Keep it moist, but not soggy. Place the plant in a sunny location. In about six weeks, growth should be evident. In a year, you probably can harvest your own pineapple.

Q: I just found your Web page on yucca plants. So far, I have not found the answer that I am looking for. I transplanted my father's yucca plants to my yard. The plants are doing very well. How do I remove the thick, flowerless stalk from the plant without damaging the rest of the plant? Do they bloom every year? These plants mean the world to me, so I don't want to ruin them. They have done so wonderfully for the last five years, but only bloomed one time. I really want to care for them properly so we can have those beautiful blooms more often. (e-mail reference)

A: You can safely cut the old flower stalk off at any time without hurting the plants. As for care, they are one of the most minimal-maintenance live plants anyone could wish for. As for blooming, that is a very high energy-requiring activity for any plant. With the yucca, as with any plant, it will bloom when the internal energy is there to do so. The plant needs sufficient time, temperature and other weather conditions to encourage it along. My advice is to keep the weeds from encroaching and let nature do 99 percent of the work for you.

Q: Three years ago we had our evergreen hedges trimmed. These professionals recommended that we cut 2 feet of branches off the bottom of the trees to make them grow thicker, which I did. I am devastated that the bottom of our hedge is now dead. We can see through to our neighbor's yard on all three sides of our garden. What can I do? The hedge is the biggest asset on our property. (Ontario)

A: Obviously the professionals did not know what they were doing and didn't understand plant growth. Evergreens should not be pruned to bare wood and any hedge pruning always should follow the "A" shape, which means narrow at the top and broader at the base to maximize sunlight penetration. You may think about legal action or reporting them to the Canadian Better Business Bureau. From a horticultural standpoint, you are pretty much out of options. The only thing I can think of is to plant another evergreen shrub in front of the existing hedge to cover up the bare area.

Q: I have a mature yew hedge. We have pruned the tops for the past two years. They are lush and full, but mostly on top. The bottoms are thinning and losing needles. Can I help regrow bottom shoots so the hedge becomes denser in the bottom areas? (e-mail reference)

A: Assuming the plants have not started spring growth, you can cut the branches back to 6- to 8-inch stubs. Do a third of them now and repeat this again for the next two springs. When making hard cuts, be sure to leave a wisp or two of green foliage behind. Prune the rest of the hedge with the base being wider than the top, roughly following the "A" shape in hedge shaping.

Q: We recently purchased a home in Sedona, Ariz. We have a plum, apricot and peach tree. During the second week of March, all the trees were in full bloom. By the last week of March, the apricot tree had fruit about the size of a nickel, the plums are the size of peas, but no peaches grew. How long before the fruit ripens? When should I spray the trees and when do they need to be pruned? I am so excited about having fruit trees. Is there a retardant for the deer and rabbits? (e-mail reference)

A: Congratulations on being a fruit tree grower! It is nice to meet someone so enthusiastic about their first crop. I'm going to refer you to the NDSU Extension Service publication on fruit tree culture that you can download. The information is available at Though this information is intended for North Dakota residents, you can adapt certain parts of it to your climate. For example, dormant oil spraying should be done before the buds open, no matter where you live. Pruning is best done during spring dormancy. Fruit trees often are oversexed, which means the trees sometimes bear too much fruit for the tree to mature. If that happens, Mother Nature takes corrective action by producing a heavy fruit drop about two to three weeks after blossom drop. You can assist the peaches and apples by hand picking some of the fruit when it is the size of a nickel. The remaining fruit then has a chance to grow to full size. As for spraying, you can apply Sevin insecticide right now and again in about two weeks. The insecticide will be broken down by the time you are ready to harvest fruit. As for repellents, some products that are available, include Plantskydd, Liquid Fence and a product appropriately called Deer Away. We have had the best luck with Plantskydd for repelling the widest range of wild beasts and for lasting the longest.

Q: My late father and I planted a small weeping willow tree about eight or nine years ago. It has done very well, but I noticed last fall that the leaves had little, black spots. Winter came and the leaves fell off. This spring a lot of the limbs look dead. Am I losing my beautiful willow tree? I am willing to do whatever I need to do to save this meaningful tree. I cannot bear the thought of losing it. I live in Pham, Ala. It does get very hot here during the summer, but my dad made sure that we planted the tree in a spot that would get and retain a lot of water. (e-mail reference)

A: I can almost guarantee you that the willow is not completely dead. Be a little more patient to see what leafs out in the next week or two. If what you see is not to your liking, you can harvest some of the green, leafed-out wood, stick it in the ground, water it regularly and watch it grow. Check some of the stems near the trunk of the tree by scratching the bark with your thumbnail to see if the cambium is still green underneath. If it is, very likely a cutting from that branch will root for you. Willows that have been around as long as yours usually don't die outright, but are plagued with any number of canker and leaf spot fungus diseases that kill them bit by bit. I've seen willows that should be dead, but still are sending out new sucker growth along the main trunk.

Q: We have a crimson king maple. This winter it developed a large crack at its base that goes up about 3 feet. The bark is peeling away in that area. The branches are turning a strange, moldy green. We do not want to lose the tree. Can you help? (Congers, N.Y.)

A: The crack probably has been developing for a long time. It could be the result of internal decay or winter sunlight hitting the south or west side of the tree causing this fissuring to take place. The crack probably was unnoticeable until it got to the size you describe. Since you are located along the Hudson River, the humidity is bound to be high during the summer months, which would result in lichen or algae growth you described. Since this is such a stately and focal point tree, I suggest that you hire a qualified International Society of Arboriculture arborist to see what can be done to extend the life of the tree. Go to to find a qualified company or individual in your part of the state. Be sure to check credentials and qualifications before allowing any work to be done on the tree. Thanks for giving me your location! That helps a lot in making judgment calls such as this.

NDSU Agriculture Communication

Source:Ron Smith, (701) 231-8161,
Editor:Rich Mattern, (701) 231-6136,
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