Improperly ventilated heaters & ethylene damage

Spring is almost here…we hope! We’re reposting this article on poor air quality damage on spring bedding crops as we’ve seen some damage again this year.  Symptoms, solutions and preventative measures are listed below. If you think you have a problem, please contact a licensed contractor to inspect your heating system.

Natural gas and propane are popular choices when it comes to heating a greenhouse.  The products of burning fuel are carbon dioxide (CO2) and water (H20); both compounds we know are good for your plants.  However, combustion is often (if not always) incomplete, and impurities such as carbon monoxide (CO), sulfur dioxide (SO2) and ethylene (C2H4) are also released leading to poor air quality if your heater is not properly vented.

Typically symptoms from ethylene damage and sulfur dioxide damage can been seen fairly quickly after exposure.

Figure 1. Signs of ethylene damage include leaf curling and epinasty, seen here in A) New Guinea Impatiens and B) lettuce seedlings.

In the short term (a few hours to a few days), ethylene damage results in leaf curling, epinasty (leaves bending downwards from the petiole) and flower drop.  If the stress continues over a longer period (several days to a week or more), plants can take a long time to flower, or not flower at all.  Ethylene levels as low as 0.01 parts per million (ppm) can create symptoms in sensitive species. Levels are usually highest near the heater and can be diluted by air circulation.

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It’s “B” Season! Watch for Botrytis, Broad Mite and Burn.

Honeybee 2Although native bees and honeybees may just be starting to gather strength and are beginning to fly outside, other “B’s” have been of growing concern in the greenhouse for some time now.

These include common spring bedding crop problems like Botrytis cinera (aka grey mold), Broad mites, and leaf burn (from a variety of causes).

Keep reading for tips on how to manage these issues during this time of year.

Continue reading “It’s “B” Season! Watch for Botrytis, Broad Mite and Burn.”