Submitted by: agcomm, Thu Sep 25 10:59:00 1997 Hortiscope Ron Smith, Extension Horticulturist North Dakota State University NOTE TO HORTISCOPE READERS: With the passing of the month of August, 1997, I have completed 12 years of continuous Hortiscopes. This comes out to 624 columns, published in about 50 newspapers around our Northern Plains region. Some people have asked if I made up the questions. I have not. A lot of you have written me many times, expressing your appreciation of my helping you. I greatly appreciate hearing that, since it is the major objective of the column. Now I need some specific help from you regular readers. As a government employee with the Extension Service through North Dakota State University, I am called on to be accountable for my efforts at educating and supplying information about horticulture to the general public. To say that you enjoy reading the Hortiscope (and other news releases) is soothing and encouraging to hear, but what I need from you now is documentation of what you have learned as a result of reading my columns. Has it resulted in any practice changes with your horticultural efforts? Have the end results of your efforts been improved because of my advice? I have no "carrots" to offer you for taking the time to write--only the continued generation of the column, which takes time. Is it worth it to you to see it continue? If so, please tell me why. Thank you! Q. I am enclosing a top of a plant that is growing in my yard. It seemed so strange that I decided to send a sample to you. Notice the markings on the leaves. Can you please tell me what it is? Thank you. (Sheyenne, N.D.) A. The sample you sent is a good one. It is Smartweed, an annual weed that is likely taking advantage of your generosity in watering your garden. I suggest keeping it from going to seed, unless you really like it. Q. We have this tree that is about 10 years old and it has something wrong with it. Enclosed is a good leaf sample and a bad leaf sample. We hope we can keep it. Thank you. (Glenfield, N.D.) A. I am glad you sent me the "good leaf" sample. I was able to identify the species of tree as a Schubert's Chokecherry. Your tree has cherry leaf spot fungus. The best control is sanitation--raking up fallen leaves each autumn. Next spring, before leaf-out takes place, spray with lime-sulfur. After the leaves unfold, spray with an all purpose fungicide. Q. I have enclosed a few leaves from a winter hardy Lillian Gibson rose. Three years ago the new spring growth froze off following a cold snap. Since that time the plant has become smaller in size and the leaves will turn yellow and fall off. It had just a few blooms this year and once again the leaves fell off. Also, thanks to one of your Hortiscope columns in the Farm Forum pages, I have been able to locate a pre-emergent without purchasing a lawn fertilizer combo for crabgrass. Will the seed of crabgrass be fertile when it continues to form a head after being sprayed with Roundup or Trimec? Thanks for your help. (Mitchell, S.D.) A. I have just one concern--Trimec and Roundup are not pre-emergent herbicides and are not used in the control of crabgrass. Several pre-emergents are available: Pre-Em, Tupersan and Dimension. All are applied in the early spring around lilac blooming time. Concerning the crabgrass, the answer is yes. The plant is killed, but not the seed. Your rose sample has a bad case of black spot, Diploearpan rosae, a fungus disease brought on by high humidity and splashing water. Several fungicides are available for control. Look for something with chlorothalinol or triforine. Application should be made as new growth emerges--every 10 days or so. Also, avoid spraying water on the leaves. After pruning back in the spring while the plant is still dormant, spray the canes with lime-sulfur for sanitization. Q. Could you please tell me what kind of problem I have with my roses? Every year they seem to be getting worse. This year they had very weak stems, so the flowers hung down. The bush didn't get bushy at all. They are planted on the east side of the building. Am I watering too much? I try to water every day, except now I cut back because the bushes look so awful. I only fertilized once this year, but other years I do it more often. They are close to a spruce tree of some kind. I would greatly appreciate some help or advice on this matter. Thank you. (Jamestown, N.D.) A. Your roses have a bad case of black spot fungus. This is brought on by water splashing, high humidity and poor air circulation. Cutback on watering to no more than twice a week. Clean up all fallen leaves in the fall. Next spring, after pruning back, spray with lime sulfur and fertilize with two tablespoons of 5-10-5. As the leaves emerge, spray with a fungicide such as Daconil 2787 to provide protection. Q. What kind of crabapples are these? They are loaded and make good jelly. (Nome, N.D.) A. Your tree is a Dolgo crab. Mine is equally loaded and it makes good applesauce as well. Q. I want to thank you for the useful information you give us all in the Farm Forum. Your column is the first I turn to when the "Green Sheet" arrives! I am enclosing a sample from a white pine (Pinus Strobus) that we planted in June 1994. In the spring the needles are completely brown like it has died. All summer I feed it Mir-acid and get it to green again. Does it have a disease I could spray for? Also, I am enclosing a sample from a pee gee hydrangea that was planted July 6. There were two bushes planted at the same time. One bush had many blooms on it, but the other is not blooming at all. I have examined the leaves, but cannot see signs of insects and the plant looks very green and healthy. Could you please advise me as to what I could do to get this bush blooming again. Thank you for your time. (Grenville, S.D.) A. Your white pine has nothing wrong with it. I am afraid that will be the nature of the plant since it is growing where it shouldn't. Continue doing what you have been and you should be able to enjoy the tree for many more years. Concerning your hydrangea, the only guess I can make is that the non-flowering one may have been pruned too late in the growing season, or it is in too much shade. From the looks of your sample, growth and leaf size appear normal, so it could be a pruning problem. Thank you for being a fan of Hortiscope. People like you make it interesting. ### NDSU Agriculture Communication Source: Ron Smith (701) 231-8161 Editor: Naomi Dahlberg (701) 231-6263