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Ron Smith answers questions about plants, trees and gardens.

By Ron Smith, Horticulturist

NDSU Extension Service

Q: My mother gave me a vase with several stems of jade and a little bit of arrow plant that were pieces off her plants. The stems must have been in the vase for a while because they had some roots established. After I brought it home, I left everything in the vase because it looks like a spring bouquet. The light-colored arrow plant leaves complement the deep green of the jade. However, I wasn't planning to keep them in water forever. In skimming through your responses to e-mails, it sounds like you recommend starting the stems or leaves in soil rather than water. You mentioned that the transition is difficult, which has me concerned. How small of a pot should I start with and what is the best way to make this transformation go as gently as possible? This is my first jade plant, so your help is greatly appreciated. (e-mail reference)

A: First, a compliment to you for being able to keep the jade stems alive for so long! You are among the blessed of jade plant lovers. I’m sure they want you to succeed in your propagation efforts. Not knowing the size the stems, I suggest using a 4-inch clay or plastic pot. Purchase pasteurized potting soil. It would be better to use African violet potting soil if you can locate it. Open the bag and wet it down completely. Allow it to drain overnight. Check the following morning for any dry spots and rewater if needed. Carefully move one or two rooted cuttings into the container (depending on the size, you might get away with three cuttings, but don't overcrowd) and set them into the soil deeply enough for self-support, but not too deeply. Water in with distilled water to secure the damp soil around the roots. The next week to 10 days is the critical period because you need to wean the roots gradually from being in a continual water environment to one of dampness and then occasional dryness. This is something that takes skill and luck. If you play it right, you will succeed. If not, you will see the result. You might want to build a little greenhouse over the transplants using clear plastic bags to keep the humidity up and lower the transpiration pull on the plant's vascular system. Gradually uncover the plants as the days pass into a week and then two weeks. Good luck! I'm pulling for you.

Q: I am going to plant 10 ficus trees as a hedge next to a building. I know they grow very large. I am very concerned that the roots will damage the brick walls in the future. How should they be planted to avoid the roots damaging the walls? (e-mail reference)

A: The problem will be nonexistent for as long as you live if you install a root barrier in a trench adjacent to the brick wall. Depending on how close they are going to be to the wall, the roots could take a decade or more before reaching the wall, especially if the drainage or grading is sloped away from the wall, which I assume it will be.

Q: I recently put in a boulder retaining wall on the south side of my house. The problem I have is that soil is washing out in the small cracks between the rocks. Is there something I can plant that will help with this problem? I have several small planting beds with creeping phlox and verbenum, but I can't get my hands in those tight spots. I am considering transplanting some moss from the north side of another building into these small areas. Will that work? (Egan, S.D.)

A: I have a couple of questions. Was any provision made for drainage behind the wall? This is going back to the old days for me when I used to do this for a living. While the boulders are the big deal here, an even bigger deal, but not as conspicuous, is the drainage arrangement that goes into place before the boulders are plopped in. The drainage usually is designed to run parallel to the face of the wall and exiting somewhere inconspicuous or through several weep holes along the face of the wall. How high is this boulder wall? The greater the height, the more pressure will be exerted on the components within the wall. I hope you had a contractor who knew about all of this stuff and considered this when constructing the wall. Vest-pocket plantings will help retain and prevent some of the soil being washed through the openings. Moss might work, as well as sedum. In some instances, if the situation is just a little weeping coming through, you might be able to block that with a little concrete punched into place.

Q: I have a lovely cactus that my boyfriend gave me. It is a tall, columnlike cactus that at times has a crown of flowers. It was doing very well in my old apartment. However, we moved across the country. During the move, the cactus was damaged at the crown. Now there is white and grey matter at the top. At our new home, it's much colder and the soil is wetter. I replanted the cactus in soil that was too wet. Realizing this mistake, I replanted the cactus in soil that is very dry. It is 90 percent sand and 10 percent dirt. I placed it outside in direct sunlight during the day. The cactus is starting to turn a little brown and gold. What else can I do to save it? I'm thinking a vitamin pack might help. It also has a small root structure that hasn’t supported its height very well. I planted the cactus a bit deeper in the pot so the sand covers a bit of the base of the stalk. Is it OK to do this? (e-mail reference)

A: I know you want to try to save this little plant of yours. You are doing everything reasonable, but I would like you to prepare yourself for replacing it if this one doesn't make it. Try to locate another cactus exactly like the one your boyfriend gave you to act as a companion or nurse plant to the cactus that is struggling to survive. If they both make it, great. If not, then at least you've made a valiant effort and can enjoy the surviving plant.

Q: I have a nice little orange tree that gets filled with flowers and then tiny, green fruit starts to grow. However, once the fruit gets to the size of a pea, it disappears. I don't see any signs of bugs. I brought it in to my screened porch to see if it was birds, but it still happens. I am in central Florida, so the tree should be happy here. What could be happening to the oranges? (e-mail reference)

A: The flowers were deprived of any sex life! No sex, no fruit. It’s as simple as that. The next time the tree flowers, vibrate the tree a little to see if that results in a better fruit set. The little pips that you are seeing are the result of nonfertilization. It is the lack of pollen reaching the ovary of the female part of the flower or the lack of mature pollen existing, which isn't likely. If it is, it, too, would not be capable of fertilization. Finally, if none of what I have suggested works, then examine the flowers when open to see if you can identify the sexual parts, which are conspicuous in citrus. If one or the other is lacking, then that's your answer. You have a freak of nature or a clone that someone developed to be a fruitless, miniature citrus. If the flowers lacked a strong scent, then that might be the answer!

Q: I am going to try one of the handicap garden boxes at our Rainbow Gardens plot. Do you have any information on what to plant and how close I can plant them in the raised, handicapped- accessible boxes? (e-mail reference)

A: The best advice I can give you is to get a copy of "Square Foot Gardening." The author describes raised handicapped-accessible boxes for gardening. This book is very complete with media suggestions, as well as plant combinations. You will be pleased at the density of the plantings you can use in this type of gardening.

Q: I live in northwestern Indiana. When we built our house about 25 years ago, some of the neighbors had arborvitae trees as fences. We liked the look, so we planted a small row of five. This spring, I've noticed the neighbor’s trees are turning brown and look like they are dying from the bottom up. A row of trees that always were thick and full are now thin. This seems to be happening to other arborvitae trees in the neighborhood. So far, mine are OK. How can I protect my arborvitae? (e-mail reference)

A: Pay attention to them on a yearly (or more) basis. Also, expect to see some wear and tear after living 25 years in an outdoor environment. Monitor for and take action against insect/disease problems when they show up. Do not overwater and do some light pruning when needed. Also, give the arborvitae an occasional shot of liquid fertilizer when they begin to look a little ragged.

Q: We've been having some weird weather for the last couple of weeks. It has been 70 degrees to 80 degrees, which made my tulips grow very fast. Now the forecasters say it's going to freeze and go back to normal March weather. Do you think it would make sense to dig the tulips out and plant them in a pot inside until the weather is better? They are beautiful flowers, so I would like to enjoy them this year. (Omaha, Neb.)

A: The answer is no to digging the tulips out. Normal March weather will not hurt them. Tulips are cold hardy plants. Your digging them out will make things worse for them. If it will make you feel a little better, get some straw and scatter it around the emerged flowers during the coldest periods.

Q: I live in zone 7. I planted my hibiscus outside, but the temperatures hit the 20-degree range once or twice during the winter. The hibiscus now is dried up. I broke some of the branches to see if there was any green left, but it doesn’t look like it. Is this plant dead or is it going to come back? How can I tell if it is dead? (e-mail reference)

A: It isn't unusual for the branches to be dead, so I wouldn't give up hope just yet. Depending on the species of hibiscus you planted, this one should start to show some new growth in a few weeks if you have anything approaching normal weather conditions. If it doesn't by mid-April, then I'd dig it up and start again.

Q: I bought a calla lily plant a few weeks ago. I repotted it and put it in my kitchen in a shaded area. It was doing great and had purple flowers. A few days ago, I noticed that the leaves were curling up and then started drooping. I put it in a sunny spot, but that did not seem to work. Does my calla lily want to go dormant? The leaves are green, but droopy. (e-mail reference)

A: It probably does want to go dormant. Allow it to dry down and die back. Give it 60 to 90 days of dry soil and then start watering the plant. It should come back.

Q: I was reading your information on arborvitae because mine seem to be off color this year. I’m also looking for the right type of fertilizer. Do I need iron or just a general fertilizer? The hurricane we had turned one arborvitae sideways, so it is growing into another. If I trim the brown a little, will it regrow? The brown parts on it now are in the sunshine. Finally, my dogs used to wet the arborvitae all the time when the plants were new, but they are alive and well 13 years later. My neighbor with the green thumb says she is surprised that I never had a problem with the plants. She figured it might have been because the dogs wet on them every other day or dog urine might not be that bad for arborvitae. (e-mail reference)

A: Try a fertilizer with both iron and nitrogen. Better yet, get some Miracle-Gro and use that. It has some of everything. As long as there is any green tissue, it will regrow. Glad the dog's urine didn't kill the arborvitae when the plants were young. You must get enough rainfall to dilute the urine or your dogs have a low salt content in their urine because of their diet. Generally, dog or any other urine is not recommended.

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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