Greenhouse Updates: Dec 14, 2016

Here are some tips for handling poinsettias in retail settings.

• Upon receiving plants, carefully unpack and unsleeve plants. Poinsettias left in the sleeve are prone to epinasty (droopy). Epinasty is caused by ethylene production and petioles of poinsettias naturally produce ethylene in response to sleeving. Symptoms are worse if plants are sleeved for long periods of time or stored (sleeved) at temperatures above 65F. Plants generally recover from epinasty in a couple of days when placed in a lighted area at 65F to 75F. However, plants may be slow to recover or may not recover from epinasty if they have been sleeved for extended periods.
• Check growing medium moisture and water only if needed. Epinasty can be mistaken for wilted plants (due to lack of water). Use caution when watering if plants have pot covers or saucers. Remove drained water to avoid "wet feet" - one of the quickest ways to kill poinsettia plants.
• Place Poinsettias in bright light at 65F to 72F.
• Place plants away from hot or cold drafts. Avoid placing plants near a heat duct or outside door that would expose the plants to sudden changes in temperature.
• Poinsettias should never be stored in an unheated area.
• Provide adequate spacing in the display area to prevent bruising bracts and broken stems when customers handle plants.
• Carefully handle and water plants to prevent bruising the bracts and breaking stems and leaves. Poinsettias are fragile.
• Always sleeve poinsettias to provide cold protection before plants go out the door! Poinsettias are sensitive to chilling injury and can be damaged when exposed to temperatures below 50 °F.  The longer that plants are exposed to low temperatures, the more damage that occurs. Red varieties of poinsettias with chilling damage have bracts with bluing or necrotic edges with inner bracts that sometimes turn a whitish color.

Holiday Plant Care for Fall and Winter (Fact sheet)
Garden retailers are invited to print and distribute this fact sheet on Holiday Plant Care for Fall and Winter to their customers.
(Note: The printable PDF version is a convenient two-fold, one-sided brochure)

Tina Smith, UMass Extension and Leanne Pundt, UConn Extension