Job offersmore »

Tweeting Growers

Last commentsmore »

Top 5 - yesterday

Top 5 - last week

Top 5 - last month

Exchange ratesmore »

How to prevent hibiscus stem breakage

The goal of every greenhouse grower is to produce a high-quality crop that is compact, well branched and in flower. In some instances, greenhouse crops may not be considered “high quality,” most likely due to constraints such as space and time or sub-optimal environmental conditions. Consistently, these constraints are the most common challenges among growers.

by W. Garrett Owen

On a recent greenhouse visit, I observed how space constraints diminished the quality of a perennial hibiscus crop. The hibiscus crop was grown in a greenhouse, pot-tight. Tight spacing inhibited plants from developing thick, sturdy branches that could support the large flower buds. Plants were tall, spindly and had few branches (Photo 1).

Photo 1. Tall and spindly hibiscus plants grown outdoors after being previously grown at close spacing in a greenhouse. All photos by W. Garrett Owen, MSU Extension.

The majority of the basal branches were broken from the main stem (Photo 2). Stem breakage was the result of plants being moved from a pot-tight greenhouse environment to an unprotected outdoor environment. Basal branches were broken from either physical (wind and water), mechanical (handling) or the sheer weight of each cluster of flower buds.

To protect plants from further damage, rings were placed around each plant to provide the additional support the plants required (Photo 3).

Photo 2. Broken basal branches of hibiscus plants caused by thin and weak stems and subsequent physical (wind and water) or mechanical (handling) damage.

Photo 3. To prevent further damage, poinsettia rings were placed around hibiscus plants to provide additional support.

The grower asked, “What caused the plants to grow tall and spindly and why did all the stems break?”

One clue is that the uniform stem breakage occurred among the whole crop and did not occur until plants were moved outdoors. Therefore, what the grower was witnessing among the hibiscus crop was the phenomenon called the “shade-avoidance response.” This is a plant response to competition from other plants, detected by a low red to far-red light ratio.

When plants are tightly spaced, there are two negative effects on plant quality. First, the amount of light available to the hibiscus plants was reduced because their leaves were competing with other plants to capture light. Second, the hibiscus leaves absorbed most of the red light, but reflected or transmitted (allowed to pass through the leaf) far-red light.

In response to the high proportion of far-red light, the stems and branches stretched in an attempt to absorb more light. As a result, the hibiscus plants grew tall, spindly and developed weak branches that broke by mechanical or physical damage. The branches were not able to support the large clusters of flower buds at the tip of every branch.

Although there is no way to “fix” the damage, some lessons can be learned to prevent stem breakage from occurring in the future. The first and easiest method is to increase the spacing between crops to allow the maximum amount of light to penetrate the canopy and basal branches. Hibiscus plants grown in greenhouse or outdoors with proper spacing and under high light intensities will be higher quality than those grown tightly spaced under low-light conditions. Overall, Michigan State University Extension advises providing as much space as economically possible to ensure plant quality is maintained.

Source: MSU Extension

Publication date: 8/16/2017



Other news in this sector:

1/11/2018 Essential plant elements
1/10/2018 How to deal with root-bound plug liners
1/10/2018 "Research into bud loss very relevant for orchid grower Tesselaar"
1/8/2018 US: Five things to consider while gearing up for spring 2018
1/4/2018 What in your irrigation water affects your media pH?
1/2/2018 India: Wayanad to be made floriculture hub
12/15/2017 US: Poinsettia production at the University of Hawaii
12/8/2017 Crop imager could enable automatic response to stressed plants
12/8/2017 US (CA): Flower farms threatened by fires
12/8/2017 India, Israel to open centre for floriculture in Tamil Nadu
12/6/2017 Turkish ice cream recipe is bad news for orchids
12/6/2017 "It’s time to put cactus on the menu"
12/5/2017 CAN (ON): For poinsettias, prevention is better than cure
12/1/2017 NL: RHP debuts video about quality mark substrates
12/1/2017 From the greenhouse to space
12/1/2017 NL: "Wooning Orchids cultivates Phalaenopsis without chemicals"
11/30/2017 US (CA): Village Nurseries donates 300 plants to irrigation trials
11/24/2017 Irrigation and peonies
11/22/2017 Italy: Cannabis grown as ornamental plants high in the Alps
11/22/2017 Influence of substrate hydraulic conductivity on plant water status


Leave a comment: (max. 500 characters)

  1. All comments which are not related to the article contents will be removed.
  2. All comments with non-related commercial content, will be removed.
  3. All comments with offensive language, will be removed.

  Display email address

  new code