Greenhouse - Iron Deficiency and Rot Rot on Pansy

Pansies have been a profitable crop for greenhouse growers over the years and are one of the first sales items to offer in the spring planting season. The following are some notes on growing problems you may see in pansies.

Pansies are fairly easy to grow but are susceptible to iron deficiencies in the media pH goes higher than 5.8. When checking pansies showing yellowing, also look for healthy roots. Yellowing may be due to Thielaviopsis root rot (also known as black root rot). Black root rot can also be kept in check by keeping the media pH below 5.6.

Thielaviopsis Root Rot on pansy. Plants are stunted due to black root rot. Photo by Jay W. Pscheidt, 2002, Oregon State University Extension.

Intervienal chlorosis on pansy with a pH level of 6.3. Photo from the University of Maryland http://www.ipmnet.umd.edu/09Feb20G.pdf

Gordon Johnson, Extension Horticulture Agent, UD, Kent County