Dying petunias may have tobacco mosaic virus
Q: I took two cuttings from a white lace cap hydrangea. Both flourished and are blooming this year, but the flowers are pale pink. I understand the different color could be because of the soil. Will you clarify this for me?
A: There is no rational explanation that I can give you unless an identity or selection mistake was made. Cuttings taken from a plant are genetically exactly the same as the parent plant and will have the same foliage and flowering characteristics as the original stock.
Q: I am getting frustrated during my first year of growing corn. All of my plants seemed to be doing well, but then I found an infestation of earwigs. The bugs were eating on the tassels. Even though I have some tassels that are pollinating, I have no silks at all. Might the earwigs have destroyed all the silk? Should I pull it all up and start over next year?
A: Welcome to the club. It looks like the garden corn crop is going to be a hit-and-miss proposition this year. You can blame most of the problems on the weather and the insects and diseases that come with it. If there is no silk, pull out the stalks and start fresh next year. Sorry!
Q: We purchased a burlap ball north woods maple three years ago. During the first summer, it had a growth surge that resulted in a 2-foot by 3-inch long split down to the inner trunk. It continues to grow vigorously, but I am concerned with the long-term prospects of the tree. Do you have any suggestions? Should I wrap the bad area in burlap?
A: Burlap wrapping the trunk during the winter months until the tree develops a mature, corky bark is a good idea.
Q: Every year my dad uses petunias for the major colors in his flowerbeds. We have had a problem around this time of year when the petunias turn into woody sticks, the leaves start to yellow and the plant stops blooming. We've been through the overhead watering, the soil with peat and sand, fertilizing and checking for disease or fungus problems. We can't figure out what is going on. Can you make any suggestions
A: This sounds like a severe case of tobacco mosaic virus. It is transmitted by leafhoppers. Unfortunately, once the plant becomes infected, it continues to decline until the plant is dead. I would suggest that your dad consider using another showy bedding plant, such as geraniums, next year. They are competitive with petunias for color and will break the cycle of using the same plant family each year.
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 firstname.lastname@example.org.