open that poinsettias are disseminate during the hot month of the year and have a very recollective output time , they are prone to several pathogen , pests , and physiologic disorders . Occasionally , glasshouse growers observe irregularities on the leave or stems of their crops that are not make by insects or diseases . Environmental factors during both multiplication and production , such as drought stress , exposure to high light or temperature , or changes in relative humidity can all cause poinsettia leaf freakishness , distortion , disabling , or puckering .
Leaf distortion and atypical meristem growth likely due to utmost environmental factors or overhead fertility . Photos by an anonymous grower .
According to Michigan State University Extension , these issues are often the most difficult to name as you’re able to not sequester the job in a petri dish or visually respect an insect or pathogen . late reports of leaf abnormalities align with the traditional occurrence of these symptoms that often occur from mid - September to early October .
Possible abiotic causes of poinsettia growth mental defectiveness
redress : Typically , as plants mature , matured leaves will cover the distorted or damaged youthful farewell and not influence the marketability of the crop .
Leaf curl and browning leafage tissue paper
Remedy : Keep plants well - water , and if plant life are drought - stressed , do not irrigate with very frigid water .
Leaf curl with browning / necrotic tissue paper is often a symptom of heat stress , leaf scorch from excessively high visible light or water system tenseness on poinsettia . Photo by Roberto Lopez , MSU .
inordinate stretch and miserable ramification
Remedy : Early fork cultivars should be pilfer between 12 and 14 daylight after transplant to forestall poor forking and stretchability . Consider also remove one to two “ flag ” leaves just below the taking into custody , leave only the bottom three or four leaves to increase light penetration to the developing break , promoting stronger and more uniform branching .
Excessive stretch of stems and pitiful branching can be a result of growing plants lot tight ( not space apart ) or from pilfer plant too of late . picture by Royal Heins and Roberto Lopez .
The first three to four weeks after transplantation are critical for the winner of your harvest . When rooted cutting are transplanted and placed in very hot greenhouses ( more than 90 degrees Fahrenheit ) , plants do not fork well and train leathery , firmly , trounce - form leaves several week afterwards . Provide shade if it is not possible to keep greenhouse temperature below 90 F.
For more detailed information on each of these consideration , more photos , and further recommendations , check out thee - GROAlert 10.36 , “ Poinsettia Leaf and Stem Abnormalities . ”
