Hortiscope

May 26, 2005

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I am so appreciative of your Web site. I am hoping that you may be able to help me. A couple of weeks ago, my new puppy pulled a branch off my ficus tree. Now the leaves are starting to turn yellow and die. The area where the branch was torn off is green underneath. What can I do to save my beautiful little tree? (e-mail reference)

A: Cut the tree back to where it is not damaged. You should see new growth in a few weeks if you treat it as you normally would. This time keep the puppy away from the plant! Good luck and thanks for the compliment.

Q: I am commenting on a previous issue concerning a cyclamen plant. I’ve had good luck with my cyclamen, which was a Valentine gift several years ago. It sits in an east window with indirect light. I water it once a week during the winter and maybe twice a week when it’s in full bloom. I water from the top, which I understand is something I shouldn’t do. When I need to, I remove the yellowing leaves and paling blossoms. It is still in its original pot, but it seems to enjoy life there! (e-mail reference)

A: Thanks for sharing your success story. Keep on doing what you’ve had success with, no matter what the experts say.

Q: Could you please tell me how to store moon flower seeds for planting next spring? (e-mail reference)

A: Put the seeds in an air-tight jar and store them in a cool, dark location, such as the basement.

Q: My 20-year-old lilac bushes bloom profusely each spring with purple flowers, but this year all the flowers are white. Why? We pruned heavily last year, which is the only thing I did differently from past years. (e-mail reference)

A: You probably pruned past the bud graft union on the plant. What you are seeing is the flower from the rootstock. That is the only rational explanation I can come up with.

Q: I am growing tomato plants in my portable greenhouse. The plants are growing great and have flowers, but don’t produce many tomatoes. Is there a trick to getting the plants to fruit? (e-mail reference)

A: The trick is to get bees involved or shake the plants while they are in flower. It will make a big difference!

Q: I recently moved my jade plant outside. Since then, some of the tops of the leaves have turned a brown/maroon color. Did I give it a sunburn? What should I do now? (e-mail reference)

A: Yes, it is sunburn. All you can do is wait for the plant to outgrow it.

Q: I’ve got a crabapple tree that is growing very fast a few feet from my house. The upper branches are taller than the house and growing into the gutters. The tree is very V-shaped and looks top-heavy. I would like to reduce the height of the tree. Can I do it without “topping” the tree? (e-mail reference)

A: Cut the tree back to a lateral branch. That way you won’t “top” the tree. If you can make the lateral branch an outside one rather than an inside one, and do this when you prune every spring, the tree will tend to grow more horizontally.

Q: I would like to plant a honeycrisp apple tree. Can I plant it alone or do I need another apple tree with it? I do have Sweet Sixteens and Haroldsons. (McHenry, N.D.)

A: Plant the honeycrisp with the other varieties in your yard. The tree should bear a ton of fruit in a few years!

Q: I have a new perennial bed I planted last spring and mulched last fall. When should I remove the mulch? When is the best time to prune shrub roses? (Arlington, S.D.)

A: You should be able to pull the winter mulch off the crowns now. If you are the least bit paranoid about the weather, leave the mulch between the plants in case the weather changes for the worse. That way you can quickly pull the mulch back over the emerging growth coming from the crowns. Pruning is best done at this time of year before the emergence of new growth, but avoid the simple act of “topping” any plant material because it destroys the natural shape or form of the plant.

Q: I have several peace lily plants. My sister brought me her peace lily, which was very root-bound. It took three pots to replant. Now the leaves are turning brown and drooping in all the pots. My peace lily leaves also are turning brown on the tips. I cut the brown part off. Was this the wrong thing to do? (e-mail reference)

A: The plant probably needs a rest period. Let it dry for six to eight weeks. This is a natural cycle in its native tropical habitat. Apply enough water to barely keep the soil moist. After that, resume normal watering later in the summer. If the brown tips persist, change to distilled water. It may be the salts in your water supply, especially fluoride, that are causing the tip burn. It doesn’t hurt the plant, but it does look unsightly.

Q: Any ideas what would make apples drop off the tree before they are ripe? In the past, the tree has been loaded with apples, but they start to drop off around mid-July. Most are on the ground by September. Thinning through the summer doesn’t seem to slow the drop. (e-mail reference)

A: Several critters out there are known to cause premature apple drop. All feed beneath the skin of the apple and cause the apples to drop in July. You can control the pest by using traps, which are available in most garden outlets. Sprays also are available. Spraying should start at the beginning of the apple blossom pink stage and continue every two weeks until three applications have been applied.

Q: Is there any benefit to adding used coffee grounds to the soil? Do I need to stir in the soil or can I add the grounds to the top of the soil after the plant has been potted? Are there other vegetables that can benefit by adding coffee grounds? (e-mail reference)

A: Used coffee grounds improve soil tilth and provide a bank of trace elements. You can stir the grounds into the soil or add the grounds to the top of the soil. All veggies benefit from the addition of used coffee grounds.

Q: I have been told that pruned trees cannot bleed to death. However, I just picked up the new issue of “Fine Gardening” that says maples can bleed to death. The writer made the statement that if maples are pruned in late winter, they can bleed to death. I have numerous maples that were pruned about a month ago. They are bleeding a great deal of sap. Your perspective would be greatly appreciated. (e-mail reference)

A: That comment, without any controlled, documented research to back it up, is the same as saying the Earth is flat and you will fall off if you travel far enough west. Pruning maples in late winter/early spring has been done for decades, perhaps centuries. I personally have done it to my maples with no adverse effects. The sap flow attracts insects that are looking for carbohydrate rich sources of food, which normally is scarce early in the season. Some of the insects get stuck in the syrupy bleed, which attracts birds that feed on the insects, as well as the flowing sap. Dormant pruning is recommended for two reasons. Branches that need pruning are more visible and the chance of disease spread is reduced greatly. The healing of any pruning wounds is rapid at this time of year, compared with any other period in the growing season, so there is an air-tight case for late winter/early spring pruning. I often tell people that if the bleeding from such trees as maples, birch and walnut bother them, then wait until the leaves have fully expanded before pruning. There should be very little bleeding.

Q: We have a cottonwood tree in our backyard. Every April, the tree releases very sticky needles. The needles get stuck in our dog’s paws and in the carpet. Is there anything we can do to eliminate these sticky needles? (e-mail reference)

A: You need to contact an arboriculture company that has the ability to spray a growth regulator. Spraying will inhibit seed formation.

Q: I have strawberry plants that must be moved. Is there anything I can do to help the young plants survive the trauma? (e-mail reference)

A: Dig up the plants with as much root as possible and pack them in damp sphagnum peat moss. If possible, keep the plants cool in a refrigerator crisper. Turn the soil where the planting is to go, incorporate sphagnum peat moss in the bed and make sure the area is free of rhizomatous weeds, such as Canada thistle or quackgrass. Plant and water.

Q: I have a couple of philodendron plants that I keep at work. I’ve had one of the plants for a long time and it is doing great. I recently received the second plant as a gift. I have noticed some of the leaves are starting to get brown spots with yellow rings around the spots. I’ve also noticed black specks that I continue to wipe off, but the specks keep coming back. The specks don’t seem to be moving. I keep both plants on the same shelf. They get sunlight from a window, but not direct light. The temperature in the office is not too cold or hot and I water them a little every other day with bottled water. (e-mail reference)

A: It sounds like one of your plant has a fungal or bacterial disease. I would guess a leaf spot fungus. Without knowing exactly what it is, I would recommend using Schultz’s Fungicide 3 because it is a fungicide, insecticide and miticide. It is derived from a neem tree, so it is not toxic.

Q: I have three hydrangea bushes that grow quite well each year and stay full and green through the season, but they do not flower. They are the big-leaf type hydrangea. I do not prune them, but I cut off anything that looks diseased or has become damaged over the winter. After reading some of your answers to people with the same problem, I am guessing that my problem is that they are getting too much nitrogen because of lawn fertilizing. Is there anything I can do, other than moving them or quit fertilizing the lawn, to help? (e-mail reference)

A: Try my old “traumatic stimulation” procedure, which is the cutting of some of the root system by inserting a straight-edge spade into the soil in several places around the edge of the foliage spread. This often shocks the plant into a reproductive cycle. The plants may be in too much shade. Plantings on the north side of a house typically are void of flowers. If that is the case, you should move them to a sunnier location for good flower production. If the problem is too little light because of tree overhang, try to open the canopy to allow more light to reach the plants.

Q: I was in your square-foot gardening session at the recent Perham gardening day. I got a used copy of Mel Bartholomew’s book and was all set to try a couple of “squares.” Then I discovered vermiculite is no longer available in the Detroit Lakes area. A fellow at a local store even made calls to several suppliers, but no one carries it. Is there someone in Fargo that has it or should I use more peat as the book suggests as a “not quite as good” alternative? (e-mail reference)

A: Vermiculite is off the market. Peat is as good or better in my opinion, so go ahead and use it. Enjoy the bounty you will get from the plantings this summer! Thanks for attending the class.

Do you have a gardening or houseplant question? Write to Hortiscope, Box 5051, NDSU Extension Service, Fargo, ND 58105 or e-mail to Ron Smith at ronsmith@ndsuext.nodak.edu. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

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Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu

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