You are here: Home Columns Hortiscope Hortiscope
Document Actions


Ron Smith answers readers questions about the world of plants, trees and gardens.

By Ron Smith, Horticulturist

NDSU Extension Service

Q: I started some tomato seeds at the end of January. They came up and seemed to be doing fine. We transplanted them into bigger pots using potting soil. The plant stems right below the soil level seem to have pinched off and the plants have all died. What did we do wrong? (e-mail reference)

A: The soil media was probably not pasteurized and/or it was kept too wet. It sounds like pythium fungus did them in. You started growing the plants too early, unless you live in the deep South. Replant with a pasteurized, seed-starting media and keep the seedlings moist, but not too moist. Have some air gently blowing across the plants to keep the stems from rotting.

Q: I’m trying to identify a native species of tree for our area that could be used in a planting to camouflage a propane tank in our yard. Can you help? (Napoleon, N.D.)

A: I think you mean suggest a species. Some possibilities are Japanese tree lilac, nannyberry viburnum or double-flowering plum or almond.

Q: There has been trenching done near some of my 100-year-old red and white oak trees. Some of the trenching came within 10 feet of the trees. Is there a chance they will survive? Is there anything I can do to help them at this point? (e-mail reference)

A: There is nothing you can do. You can hope the trees will tolerate this abuse and not go downhill. You might have an International Society of Arboriculture certified arborist inspect the trees for soundness. Be sure to check the arborist’s credentials and get references before allowing any work to be done.

Q: Our daughter just bought a home in Plant City, Fla. The previous owner planted two oak trees on top of the septic tank. He told her not to worry because the root system was very shallow. She is prepared to have the trees cut down if necessary, but I told her to hold off until we could get some advice from you. It would be a shame to have to remove these beautiful trees and probably would cost more than what is in her budget right now. Thank you for your interesting column. (Madison, S.D.)

A: I would leave the trees because you don’t know if the trees ever will be a problem. If there comes a day when the trees become a problem, you can decide then what the next course of action is.

Q: Last fall (October), I purchased 25 blue spruce trees from a nursery and planted them according to the instructions. The trees were about 18 to 24 inches tall and planted in sandy soil. The trees turned a golden brown during the winter. Is this normal? Are they dead? Is there anything I can do? Please help! (Wisconsin)

A: Don't give up just yet. If the buds are firm and green, the tree is alive. If the buds are brown or crumble when you squeeze them, the tree is a goner and there is nothing you can do. Assuming the better news, when the frost is out of the ground, keep the trees watered, but not soggy. The trees should recover.

Q: My stepdad and I potted some spiderettes today. However, I then read where you said to wait until the roots are a few inches or so long or keep them attached to the mother plant for a few weeks. The roots on my little ones are about one-half inch long. Is there any hope? Also, I've heard that it's really good to take potted plants in the bathroom when you shower so the plants are exposed to humidified air. Is this true? Thanks for your help and for being such a great resource! (e-mail reference)

A: The spiderettes should be OK. Keep the soil moist, but not soggy. Allow the plants to dry down a little. It is true that all houseplants, except cacti, enjoy the high humidity of a bathroom whenever a shower or bath is being taken.

Q: I saw your Web site about tree problems. At the back of our property are six very old poplar trees. In the last few years, the trees slowly stopped flowering and growing leaves. The top branches have started to break off in the wind. Then the bark, starting from the top, fell off. Now the trees are dead. The bark can be peeled off by hand, revealing many small holes. There are a couple of small zigzag indentations I observed in one area. How can I tell if the trees died of old age, woodpeckers putting in holes or devastation by Asian long-horned beetles? Our city has had a couple of areas affected by Asian long- horned beetles. (Toronto, Canada)

A: The Asian long-horned beetle damage would almost be the size of a .22-caliber bullet hole. Poplars seldom die of old age. Death usually is caused by a smorgasbord of bark beetles, borers, assorted fungal diseases and cankers. If you want an accurate diagnosis, you should employ the services of an ISA certified arborist. Not all ISA arborists are equally competent in this area of tree expertise, so be sure to specify what it is you want done.

Q: I have a very old jade plant that was started from a small cutting about 35 years ago. It's getting too tall. I would like to cut it about 6 inches below the lowest branch. Do you think it would survive a pruning that severe? If so, how would I get it rooted once again? (e-mail reference)

A: That is a very beautiful jade. Too bad you can't keep it that way. Do some light pruning rather than the drastic operation you mentioned. If you cut it all the way back the way you want, I'm certain that the little shoots around the base would take off and develop into a beautiful plant again. You probable would get at least 100-plus cuttings from the plant parts you would remove. You have no idea how many jade growers or wannabe jade growers would love to have a plant like yours!

Q: Someone just gave me a tulip plant. Is the plant dangerous to cats? (e-mail reference)

A: No, it is not. However, I suggest trying to discourage the cats from consuming the plant’s foliage if you don't want a mess to clean up!

Q: I have a beautiful song of Jamaica, but I am not sure how to take care of it. I was told not to let the soil dry. However, I already have lost two trunks out of five and the leaves are yellow and drooping. One trunk turned brown/black and dried up. The house is kept quite warm. The plant does not get direct light, but does receive light all day. Any information you have for me would be great. (Vancouver, Canada)

A: I am not familiar with this particular cultivar of dracaena. However, you obviously are keeping the plant too moist. Allow the soil to dry down before watering again. We’ve had a couple of Janet Craig plants for close to 20 years that we don’t water more than once every 10 days. It sounds like you have it in enough light. As a species, they are among the top 10 toughest houseplants and were used in NASA research to see how well they would remove pollutants from the air. The plants performed right along with the best. So, stop being so kind to the plant!

Q: I live in central New York state. I would like to plant a windbreak using Colorado blue spruce. How close together should I plant them? Should I plant more than one row? Any information you can share with me would be great. (e-mail reference)

A: I would suggest planting a double row with staggered spacing at 12 to 15 feet on center. It will make a nice, dense windbreak in a few years. You could plant them closer for a faster effect, but that usually leads to quicker disease problems before they get large enough.

Q: The beauty of the majestic Dutch elm tree is hard to replace. I have read that cathedral elm might grow well in the Fargo area. What can you tell me about cathedral elm trees? I wanted to buy one last spring, but was unable to find a supplier. Do you know where it can be purchased? (e-mail reference)

A: The cathedral elm will be sold at Baker Nursery in Fargo. I assume other garden centers in the area also will have them in stock.

Q: Can you please tell me how to care for Easter lilies? Can I plant them outside? If so, when can the lilies be planted? (e-mail reference)

A: Almost no care is needed. Keep the soil from completely drying out and remove the spent flowers. After the danger of frost is past, plant the lilies outside. They are pretty tough customers!

Q: I'm in the process of taking on a challenge by planting a plumeria from Hawaii. I've succeeded once before when we lived in Duluth, Minn. Due to circumstances beyond my control, I no longer have this beautiful plant. I am ready to try again, but need some advice. What kind of grow light would be beneficial for this or other plants? How far away from the top of the plant should the light be? During the summer months, I plan to set it outside for true sunshine and heat. Would direct or indirect sunlight be recommended? My husband has a shop light. Could a plant bulb be put in the shop light to serve the same purpose? (e-mail reference)

A: A shop light with two grow bulbs installed would do. Place the light about 6 inches above the plant. I would suggest eastern light.

Q: I was wondering if you could tell me why my baby jade plant has little, white dots all over the fleshy leaves. (e-mail reference)

A: The white dots could be crystallized salts on the leaves that have come through the stomata openings. Using your fingernail, see if the spots scrape off with a little coaxing. You probably have nothing to worry about.

Q: I have a question about a California live oak in my front yard. The tree is almost 40 feet tall and, according to an arborist I once hired, the tree is more than 300 years old.Three years ago, we experienced a record rainfall. The ground became so wet and soft that it was just mud. The oak tree, which has always leaned, began to lean more after a night of particularly heavy rain and wind. The tree has not moved since and it looks vigorous and healthy. However, I'm concerned that the root system could have been damaged when the tree moved. If the roots were damaged, will they repair themselves or continue to degenerate until they fail? Could the roots be damaged, but the tree still look fine? I obviously don't want the tree to damage my property or hurt anyone. However, I also don't want to cut it down unless necessary. My property would not be the same without it. (Los Angeles, Calif.)

A:Thanks for being concerned about such a worthy specimen. Basically, it all depends on the lean it has developed. Many a tree that has a good lean to it has outlived human admirers. If no roots protruded, or if the root plate was not thrown, you probably are OK. I'm in no position to make a judgment on this, so I would contact an ISA certified arborist to see if it is a hazard.

Q: We bought a beautiful bleeding heart plant. Can I keep the plant potted and in the house? We have a dining area with a full ceiling and cover film over the glass. All our other plants do wonderfully in the same area. (e-mail reference)

A: How I wish I could tell you that you could, but I can't. It will die. Bleeding hearts need to be planted outdoors to go through the changing seasons. In the meantime, you can enjoy the beauty it is bringing into your home. Once it fades, plant it outdoors in an eastern exposure.

Q: Some years ago, a large, potted dieffenbachia I had broke off just above the soil line (a ladder fell on it). I put the broken stems in water. The stems developed extensive roots. They have been living in plain tap water for about three years and appear healthy and attractive. However, just as with dieffenbachia growing in soil, they tend to lose the lower leaves and put on new ones above. While the color of the new leaves on my hydroponic plant is good, the leaves are smaller than the originals. I feel the plant needs some nutrient it isn't getting. Can you suggest a way to fertilize in this situation? (e-mail reference)

A: Three years in just tap water? You must have very mineral-rich water to sustain the plants this long! The closest thing to providing a fairly complete nutrient cocktail that is readily available on the retail market is Miracle-Gro. I would suggest making up a very dilute solution and add it to your water. Better yet, I encourage you to plant them in pasteurized potting soil for easier management and better looking plants.

Q: I have had my jade plant for a few months. It sits in a south-facing garden window. We live in Ohio, so it hasn’t had a lot of sunlight. The leaves seem to have taken on a reddish-brown color around the very edge. Is that a problem? (e-mail reference)

A: That might be the characteristic of the particular cultivar of the plant, so I don't think you have anything to worry about. In low light situations, the leaves would remain a normal green color. Even in Ohio, enough sunlight gets through in the winter months for the plant to show this marginal leaf coloration. If the plant is otherwise healthy, you have nothing to worry about.

Q: My question is about my geranium. It appears to be a vibrant, healthy plant. At the time of purchase, it had two lovely blooms and a lot of buds. I keep it in a spot that gets a lot of sun. I don't think I overwater it (every other day), but none of the buds have blossomed. Right before I think a bud will open, it dries up and falls off. There is no other evidence of malnourishment. The plant is full, the leaves are deep green and beautiful. The plant has a ton of buds. Also, I see no sign of bugs. Is it because I live in Denver and the air is too dry? Should I mist the plant? What about a fungus problem? (e-mail reference)

A: You probably nailed the reason. The plant probably was grown under ideal greenhouse conditions before you purchased it. The move to your drier house probably is the cause of the problem. It likely will be all right and acclimate to its new environmental conditions. It wouldn't hurt to mist the plant with some distilled water on a daily basis or place it on a tray of stones and water to keep the humidity high around the plant.

Q: When a small, earthen dike was built around our property a few years ago, the heavy equipment operators tore out most of the trees and other vegetation in our yard. Now we have no privacy from the road. Are there any fast-growing trees or shrubs that we could plant on top of the flood dike that would offer a screen from the road? (Ada, Minn.)

A: How about common lilacs? They are beautiful, inexpensive and grow quickly to about 18 to 20 feet tall. Their suckering habit will provide a nice, dense screen between you and the road.

Q: How deep do I plant my tomatoes? (e-mail reference)

A: As deep as you can. Plant the seedlings up to the top leaves, but remove the lower ones first before doing so. Deeper planting will result in more root mass and greater uptake of water and nutrients.

Q: I bought some tulips that had bloomed. After transplanting them outside, the petals wilted and fell off. I am wondering if they will come back this year or am I going to have to wait until next season? If they don’t come back this year, can I dig them up and move them somewhere else? (e-mail reference)

A: Making retail purchases of tulips already potted and in flower is a cruel joke for the consumer. Consumers love the flowers, but they quickly fade, which is followed by the foliage. The plant then will not have enough energy to restore the bulb for blooming the next year. Those selling the tulips should put a tag on the plant that tells consumers that these bulbs will not rebloom as houseplants or outdoor plantings. Tulip bulbs should be purchased and planted in the fall. The bulbs then go through the required chilling or cold period in the soil and emerge in the spring with an array of beautiful flowers. The flowers will last for seven to 10 days, depending on the temperatures. Once spent, the flower stalks should be removed to prevent energy from being put into making seed. During the next several weeks, the foliage goes from green to a faded yellow. When the foliage can be separated from the bulb with gentle tugging, the bulbs will have stored sufficient energy to rebloom the following spring.

Q: I planted some small hydrangea plants last spring. They did OK for the summer, which means I didn't kill them right away. This spring, they lost a lot of leaves. The leaves that are left are mostly red. I am not sure of the type, but they are the kind that can be blue or pink. Mine were more purple. I live in Florida and am horrible with plants. Also, the full-sun plants did the same as those in partial shade. Is there any help? (e-mail reference)

A: If you don’t know the species of hydrangea, then I can't help you very much, especially with you living in Florida. I'd suggest contacting the Florida Extension Service at for help.

NDSU Agriculture Communication

Source:Ron Smith, (701) 231-8161,
Editor:Rich Mattern, (701) 231-6136,
Prairie Fare: Prairie Fare: De-stress with Gardening  (2019-05-23)  According to researchers, gardening can be beneficial for mental, physical and social health.  FULL STORY
Use of Releases
The news media and others may use these news releases in their entirety. If the articles are edited, the sources and NDSU must be given credit.

Powered by Plone, the Open Source Content Management System