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Don Kinzler, Published February 17 2012

Hortiscope: Norfolk pine reacting to dry environment

Q: We are developing a lot off Douglas Bay on Lake Sakakawea in McLean County. I was listening to you on one of the radio talk shows where you said to send you an email if a person had any questions about planting in certain areas of North Dakota. We would like to plant a row of shrubs on each side of our lot. Can you give me any suggestions on what would work well in this area of the state? We had thought maybe some type of lilac with two or three evergreens near the road or edge of our property. Any suggestions you can give us would be appreciated. (email)

A: There is a publication at www.ag.ndsu.edu/pubs/plant

sci/trees/f1055w.htm that goes through design and plant selection combinations for you to consider. It should answer any questions you might have. If not, feel free to get back to me.


Q: I have about 80 apple trees that produce very little fruit. Most of the apples stay small and then drop. After a month of the growing season, the leaves become yellow and then turn brown and fall off. On 15 percent of the trees, I have some branches that turned black. I did prune those branches off. On top of that, I have some scab that I want to get rid of. What’s happening? Do I spray after the buds begin to swell? I live in California, so I can’t use lime sulfur.

Thank you for your help. (email)

A: You need to contact your local extension agent. Go to http://ucanr.edu/County_

Offices to make contact. I cannot take care of your problem with the information you provided. Local assistance would be more appropriate and useful.


Q: I have a 10-year-old Norfolk pine. About a month ago, it started dropping its lower green branches. It always has been a healthy plant. Is there anything I can give it to help it? It gets indirect light and is in a large pot. (email)

A: This is an unfortunate reaction to a dry environment from a forced-air heating system during the winter months. I don’t know what you did in previous years to keep this from happening. Did you mist the plant or have it in another location where it wouldn’t be subject to as much warm, dry air? Once dropped, there will be no branch regrowth taking place. All you can hope to do is try to keep any more foliage from dropping by misting it or moving it to a different location.


Q: I have had my Christmas cactus for more than a year. The plant is green and looks healthy, but it isn’t growing. When I got it, I took it out of the plastic pot and put it in another pot that wasn’t very much bigger. Does it take a long time to noticeably grow? It also hasn’t flowered, but I think I know the reason for that. (email)

A: Your plant probably isn’t getting enough indirect light. I would encourage you to get a plant light and put it on a timer for 14 hours a day from now until next October. Then back the hours off to about 10 or 11 hours of supplemental light and reduce the watering somewhat. Also, put the plant in a cooler location, especially at night. By this time next year, you should be telling me about the sumptuous plant growth and the beautiful blooms it is producing.


Q: My family lives on a hilltop. I was raised in the Red River Valley and my parents and grandparents always had beautiful raspberries. The bushes originated from a small patch of bushes started by grandmother in the early 1950s. They were transferred to each new home the family moved to. After my parents sold their last home, I brought some bushes to our home. I planted them in a small garden and mixed some compost into the soil. So far, the berries have been small and hard, even though the plants get watered frequently. Is there more I can do to get full, juicy berries or is this area too dry? (Mandan, N.D.)

A: The hilltop may not be the right environment for this variety of raspberry.

In New York, my raspberry farm was on a hilltop and along a south-facing slope.

Basically, the hilltop plantings produced the plumpest berries for me. You might try a new cultivar of a couple of plants to see if they produce a better berry.

It also could be that the plants have a virus that is affecting berry quality.

If that is the case, any new plants need to be planted a distance away from the established planting.


Q: I received some tulips as a birthday gift. They are so beautiful, so I wanted to save the bulbs for replanting. I’m pretty familiar with how to deal with bulbs that have been planted outdoors, but I’m not quite sure about one aspect of preparing a potted tulip for replanting. I know I need to deadhead the plant once the flowers die and I know that I need to allow the leaves to turn yellow until they easily pull out of the bulb. After that, the bulb can be dug up and refrigerated. However, do I continue watering the bulbs in the pot after the flowers have died or do I allow the soil to dry out? (email reference)

A: A tulip bulb is a very efficient storage organ, so it doesn’t need continuous watering once it has entered dormancy. The bulb also should not be allowed to sit where forced-air heat can gradually work on dehydrating it. For someone like you, the best route to take is to store the bulbs in the crisper of your refrigerator. Surround the bulbs with damp, unmilled sphagnum moss. This will keep the bulbs healthy and appropriately hydrated and take away the threat of rot getting started.


Q: I have gathered approximately 200 eastern red cedar seeds. I plan to start growing the seeds in a greenhouse that I just built. While I’m pretty good at building things, I have almost no experience growing things. I found your response to a question about growing these trees from seeds and would like to learn more. What references would you recommend that I could use to further expand upon the information on your website? (Charlotte, N.C.)

A: We ought to get together because I’m good at growing things but mediocre at building things. If you want more security or background information than what you have, go to www.amazon.com/Hartmann-Kesters-PlantPropagation-Principles/dp/0136792359 or http://cru.cahe.wsu.edu/cepublications/pnw0152/pnw0152.html or http://plants.usda.gov/plantguide/pdf/cs_juvi.pdf. Let me know if there is anything else I can help you with.


Q: I was wondering if you could recommend a juniper we could plant as a border on our property. We have cedars now, but the deer are eating all the foliage. Are junipers more deer-resistant? (Appleton, Wis.)

A: Deer will eat anything if they are starving, so you need to do a combination of actions. Try to select evergreens, such as junipers, blue spruce, Canada hemlock, pines or Douglas fir, that are resistant. Treat what you purchase with Plantskydd Deer and Rodent Repellent. Of all the products on the market, this one appears to be the most effective at detouring the deer from your property.

It needs to be applied early in the season before deer roaming begins. Reapply it during the winter months according to the directions on the label.


Q: I believe my apricot tree has a bacterial canker. The University of California at Davis website just says to make sure to water the tree regularly and fertilize. What should I use as a fertilizer? Is there anything else I can do for the tree? The university mentions nematodes, but I have no idea what to look for. (email)

A: Nematodes are a distinct possibility in your part of the country. I would advise sending a root sample with some surrounding soil to the lab at U.C. Davis for analysis. It is a simple determination that is done with a binocular microscope. The most common strategy for controlling diseases caused by bacterial canker pathovars is, as it has been for more than a century, to spray bactericides. These include a variety of copper compounds, such as the traditional Bordeaux mixture, cupric hydroxide, copper sulfate, ammoniacal copper, copper salts of fatty acids or other heavy metals, with or without various combinations of fungicides or other pest-controlling chemicals. These compounds were the first biocides used for disease control and are the only bactericides registered and allowed for use on most crops. They are especially effective if applied in the proper manner. Use a good sprayer, keep a precise spraying schedule and cover both sides of the leaf when spraying. These factors are crucial to avoiding a wide-spread epidemic. Be sure to check local regulations on the legality of using any of these compounds. California pesticide laws are more stringent than most other states.


Q: We have enjoyed reading your website and appreciate the wealth of knowledge you offer. We recently moved to a property where one of the blue spruce trees fell over a few days after a big wind. About two weeks later, another spruce tree next to it fell during a wind storm. I am guessing that these trees were about 40 feet tall or more. Is it odd that both trees fell within such a short period of time? Is it because one fell so the other was more exposed to the wind? We are concerned that the issue wasn’t just the winds. Could it be that the soil in this area is contaminated or there are bugs or diseases that will affect other trees we plant? We had an unusually wet spring followed by very dry weather during the summer. We now have a lot of snow and wind. One of the trees fell on top of an old apple tree that we were planning to prune to see if we could bring it back to a healthy state. We hope the apple tree isn’t damaged. I am sending along some photos for you to look at. (email)

A: Those huge trees are a sail in the wind. There is nothing wrong with the trees that I can see. However, any time a tree that size is subjected to a combination of wind and saturated soil, the roots would have to be made of steel girders to keep them from snapping. Often, a cluster of two or three spruces will have intertwined or grafted roots together that provide mutual stability for each other. Losing one from such a group can expose the others to greater wind vulnerability. The apple tree can be salvaged with the removal of the spruce and a careful pruning job. It won’t be very pretty, but it should be productive for you once you are done giving it a little tender, loving care.

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 email ronald.smith@ndsu.edu.