Hortiscope: Local reader: Do horses thwart tree development?
Q: I was reading an article that you wrote in the Park Rapids Enterprise about horses chewing on trees and the damage they do to the land. I have 75 acres of land that is about 70 percent wooded. I rent it out during the spring, summer and fall to a cattle rancher who has about 15 head on it.
What am I sacrificing as far as tree redevelopment and the land as a whole? I'm not sure if this is a question you can answer. If it isn't, do you know who I could ask?
A: I'm not an expert on this, so I've contacted my colleague, Kevin Sedivec. He is a professor in the NDSU Animal Sciences Department and is far more knowledgeable than I am on this subject. For more information, contact Sedivec at firstname.lastname@example.org. Sedivec's answer: In reading your e-mail, I would assume you live near Park Rapids. Fifteen head of cattle on 75 acres (50 woodland, 25 grassland) could compromise the sapling development of the hardwood trees.
I would assume the cattle graze the grassland for forage and pick the woodland as a secondary source. However, cattle will loaf in the woodlands during the heat of the day and when the flies are bad. The cattle consume the forage in proximity, especially sap-lings, because typically they are the most palatable. Without seeing how the cattle are behaving in the woods, they may or may not be negatively impacting sapling development. My recommendation would be to visually assess the sapling growth and cattle use. Grazing management strategies can be implemented to reduce the risk of damage.
Q: I planted some dahlias this spring in a large planter. They sprouted, but never bloomed. Now that it is cold, I brought the plants inside (before any frost) in hopes that they might bloom. Are my expectations too high? What should I do?
A: Your expectations are too high. Set the container back outside and let the top get killed back, then dig out the tubers and bring them inside for storage through the winter. Replant the tubers next spring after the danger of frost is past. Try to put the container in a location that gets full sun. Don't push the plant with excessive fertilizer. It needs a little "hunger" to bloom.
Q: I have two tropical indoor hibiscus plants. On one plant, some leaves are turning yellow with black spots on the underside. What would cause this?
A: You need to get a magnifying glass to carefully examine the discolored leaves and determine if they are being affected by insect or mite activity. Leaf discoloration usually is caused by two possibilities if no insects are found.
The plant may be in a spot where the light is too low or not exposed to light long enough. The problem also could be overwatering. Diseases seldom are the cause of this problem, so check out your watering (drainage) and light intensity before looking for insects or diseases. In the meantime, isolate the plant showing the symptoms you described in case it is caused by insect or mite damage.
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 email@example.com.