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Ron Smith answers questions about flowers, trees, gardens and shrubs.

By Ron Smith, Horticulturist

NDSU Extension Service

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? (Park Rapids, Minn.)

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 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 saplings, 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: Why do grape leaves fall off the vine in early winter? What happens physiologically? What triggers dormancy? (Napa, Calif.)

A: These questions would be a course in plant physiology, but here is what happens. Dormancy is triggered by the shortening day length. Each plant species has an internal clock that reads the day length changes. After it reaches a critical point for that species, growth stops and the process of preparing for winter begins. Next are the temperature changes that come with the shortened day length. If it should reach a critical point (usually at or below 32 degrees), an abscission layer is formed between the leaf petiole and the stem to which it is attached. This causes the leaves to drop. There is much more involved, but this is a nutshell rendition of it.

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? (e-mail reference)

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? (e-mail reference)

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.

Q: How do you get nice, thick stalks on jade plants? (e-mail reference)

A: Back in the 1970s, an interior plantscape designer noticed that interior plants that were subjected to regular air movement had more flex in the trunk and branches and were thicker and more robust. These stout stems were not subject to flopping over or breakage. Of course, good light was needed as well or else the air movement was not effective. That's the good news. The bad news is that you can't convert a skinny stem, branch or stalk to a robust one because it has to be trained from the start. To accomplish this with a current jade plant that is too thin and weak to support itself, take cuttings from the end of the branches or just some healthy leaves. Make sure it has plenty of light from a plant light for 12 continuous hours a day. Run an oscillating fan over it for the same length of time. As the cutting grows, it will develop what is known as stressed cell tissue that is thicker-walled than nonstressed tissue. This will result in a plant with nice, thick stalks. You also can cut the skinny plant back to a branch or stem on the lower part of the plant and execute the same treatment on the resulting new growth.

Q: In March, taking your good advice, I propagated several cuttings from my woody 8-year-old goldfish plant. I now have five or six plants per pot that are healthy and growing. I want to transplant them to a larger pot, but I’m not sure how to do it. Should I plant all of the cuttings in the small pot together into a larger pot or am I supposed to plant each individual cutting into its own larger pot? Also, how long will it take for the new plants to start blooming? They are growing beautifully, but not a flower in sight! (Grand Junction, Colo.)

A: If you are good with your hands, carefully separate the individual plants and put them into slightly larger pots. I am not a genie, so I cannot tell you how long it will take the plants to bloom. However, they will bloom faster if you follow some advice. Mist the foliage frequently, but keep the soil on the dry side. Keep the night temperatures as low as you can stand (about 60 degrees). Provide the plants with plenty of bright light, but not direct sunlight. If you add a little patience, they will get around to producing flowers for you. I'm glad the cuttings rooted so well and are growing beautifully. Just hang in there!

Q: I saw your Web site and am wondering if you could answer a question I have about my ficus plant. We bought it from a store. After a few weeks, the leaves started falling off and now there are no leaves left. The branches look dry, but the trunk still looks healthy. Is there hope for the tree? What do I need to do this winter to keep the plant healthy? How do I take care of it if I live in a place that is mostly cloudy and rainy and dark by 5 p.m. in the fall and winter? (e-mail reference)

A: Total leaf drop is unusual for a ficus plant that was just purchased. Some drop is to be expected, but not total leaf loss. The fact that the trunk is green would lead me to believe that a good many of the branches are, too, and would indicate that there is a chance the plant will releaf. Low light will kill the plant eventually, so you need to get a hold of a plant light and put it on a 12-hour timer for it to recover and thrive. Winter care should focus around not overwatering it. Give the plant water when the soil is dry to the touch up to the first knuckle. Never fertilize unless some new growth, not just releafing, is taking place.

Q: I have a big, beautiful Thanksgiving cactus with coral blooms. I came down the stairs Saturday and saw a big chunk of the plant lying on the floor. I guess it was so heavy it fell out of the pot. I could tell there was still a root attached, so I replanted it. Right now it is droopy, but it is green and it doesn't look like it's going to die. Do you think it will live? Should I be doing something else with it? Thanks for any help you can give me! (e-mail reference)

A: Thanksgiving cactus is an amazing plant because of its ability to recover. There isn’t anything special you can do to accelerate its recovery. Provide normal care, don't overwater and try to give the plant some physical support while it is attempting to re-establish itself. Give it plenty of light, but not direct sunlight. You also can use a plant light. Check around the base of the plant to see if any rot is starting to develop. If there is, cut it off back to some healthy tissue by a few inches. Allow it to sit in open air on a counter for a couple of days so it will callus over and then plant it in a peat-based potting soil. In fact, to make life easier for this plant, remove some of the pods from the end of the plant and allow the cut end to callus in the air for a couple of days. Insert the pods in the peat media for rooting. Go to for a publication to assist you. You can download the entire publication or just the parts that interest you. The good news is that it is free!

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

NDSU Agriculture Communication

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