commercial greenhouse

Poinsettias: From Production to Decoration

poinsettia plant in greenhouse
E. eremicus. Photo: Leanne Pundt

Wholesale growers across Connecticut started shipping poinsettias in mid-November. Poinsettia are a long-term crop, started from rooted cuttings in early to mid-July.    Plants are pinched to promote branching and growers measure the height of the plants on a weekly basis, and enter data into a computer program, to make sure the plants will be at the desired height for their customers. These particular poinsettias were grown using biological controls. Whiteflies can be a troublesome pest for poinsettias, because homeowners can object to even one whitefly on a plant. Using biological controls, growers regularly release a small mini-wasp, Eretmocerus eremicus that parasitizes the whitefly nymphs. In the photo at left, you can see pupae glued to paper cards. Growers also release a predatory mite, Amblyseius swirskii that feeds upon whitefly eggs and nymphs. Biological fungicides are also used to prevent root rot diseases.

Poinsettias (Euphorbia pulcherrima) are originally from Mexico. In the 20th century, the Ecke family of California was

poinsettias in a Connecticut greenhouse
Photo: Leanne Pundt

instrumental in the development of the poinsettia as a potted holiday plant. Today, there are hundreds of compact, long lasting cultivars. Red continues to be the most popular color, however, white, pink, and specked or marbled varieties also sold.  The flowers of the poinsettia are the small, cup-like structures at the center of the showy “bracts” which are modified leaves.

Retail Care Tips

Place plants in a sleeve to protect them from temperatures below 50° F when bringing your plant home. Be careful not to overwater your plants, they are very susceptible to root rots. Place poinsettias in a bright, sunny location away from hot or cold drafts.  Poinsettias are not poisonous, but their milky sap can irritate the skin. December gardening tips are available from the UConn Home and Garden Center.

By: Leanne Pundt

New Greenhouse Pest Guide Web App

Pest app

 

http://tiny.cc/greenhousepestguide

 

Try our new mobile optimized website app for commercial growers that contains options for biological control and pesticides for management of insect and mite pests common in commercial greenhouse production.  This app can be used on your computer, smart phone or other electronic device.

 

This was a cooperative project between Leanne Pundt of UConn’s IPM program and Tina Smith, Project Leader, Extension Floriculture Specialist for the University of Massachusetts Greenhouse Crops and Floriculture Program.