Poinsettia branches that develop after pinching may develop a few distorted and misshapen leaves, reported Leanne Pundt, extension horticulture and greenhouse IPM specialist at
Environmental stress, overhead applications of phosphorus fertilizers or abrasion may lead to distorted leaves. She said for last year’s crops, the high temperatures that occurred in August may have contributed to this phenomenon.
Changes in temperature and humidity as plants are moved from propagation to finishing production areas also lead to leaf distortion, she said. This distortion becomes apparent as injured leaves grow and expand.
Often, thrips feeding is blamed for distorted leaves. She said poinsettias are not a favored host of thrips. With thrips feeding you should see white scarring. Thrips may migrate from bedding plants, garden mums or weeds onto poinsettias.
For more: Leanne Pundt, University of Connecticut, Litchfield County, 843 University Drive, Torrington, CT 06790-2635; (860) 626-6240; fax (860) 626-6897; leanne.pundt@uconn.edu; www.negreenhouseupdate.info.