December 8, 1993

Needle Diseases of Conifers


A number of Austrian pine samples have been submitted to thePlant Disease Clinic recently showing Dothistroma needle blight,Diplodia tip blight, or both diseases. Theses diseases are acommon problems on Austrian pine and are fairly easy to recognize.

Dothistroma needle blight, which occurs primarily on Austrian,ponderosa, and mugo pines in Iowa usually occurs first on lowerbranches. Infected needles show yellow to reddish-brown spots orbands that extend around the needles. Needles die from the bandedarea to the tip. Diseased needles drop prematurely.

Do You Believe Poinsettias Are Poisonous?


This question wasasked of 1000 Americans by the Society of American Florists in1993. The answer, 53% believed incorrectly that the plant ispoisonous to humans and animals. Another surprising answer, 52% ofthe floral clerks surveyed also believed that poinsettias arepoisonous.

Winter Care of Houseplants


Winter weather adversely affectsgrowing conditions for houseplants in Iowa. Proper care during thewinter months can help insure the health of houseplants.

Temperatures

Most houseplants grow well with daytime temperatures of 65 to75 F and night temperatures of 60 to 65 F. Temperatures below 50 For rapid temperature fluctuations may damage some plants. Keephouseplants away from cold drafts, radiators, and hot air vents.Also make sure houseplant foliage doesn't touch cold windows.

Relative Humidity