Snow that accumulates on a greenhouse can put significant weight on the structural members. Snow can be light and fluffly with a water equivalent of 12 inches of snow equal to 1 inch of rain. It can also be wet and heavy with 3 inches of snow equal to 1 inch of rain. Snow having a 1 inch of rain water equivalent will load a greenhouse with 5.2 psf. This amounts to 6.5 tons on a 25' X 96' greenhouse.
Cool outdoor temperatures continue and energy costs are high. Some things to consider if you are growing crops cooler to save energy costs:
Seed Germination: Donâ€™t skimp on heat here. Temperatures too cool during seed germination will delay germination, reduce percent germination and decrease the uniformity. For most species, germination media temperature should be 72F-76F. After a crop is established, most plants will tolerate non-optimal temperatures more easily.
Did you ever consider how much heat loss there is through fan and intake shutters?
Heat loss through a shutter occurs by conduction through the metal or plastic and by air exchange (infiltration) through the cracks between the blades. If the shutter closes tightly, then most of the loss is by conduction. If the blades are bent or if the hinges are sticky, then infiltration can be the greatest loss. I have seen shutters that were open during the winter with gaps as wide as 1â€.
The accuracy of a disease diagnosis can only be as good as the sample provided. To provide a good sample, be sure that the sample contains the right part of the plant. Symptoms may appear in parts of the plant that are not infected with the pathogen. For this reason, if possible, submit as much of the plant as possible. Ideally, this would be an intact plant.
As plant material is received and handled during this busy time, here are a few guidelines to have greater successes and fewer problems.
Open and unpack the boxes immediately upon arrival and check the physical condition of the plants. Also inspect plants for root and foliar diseases and for insects and mites. Report any damage or discrepancies immediately to your supplier (most companies want to hear within 24 hours).
Growers are cautioned that cold night temperatures are expected this week in most areas. Watch weather reports for your area and plan to cover susceptible plant material growing outdoors.
Sometimes poinsettias are prone to lateral stem breakage and some varieties such as Freedom may be more susceptible to this problem. The crop may look healthy and the roots look good, yet an occasional branch will wilt for no apparent reason. There are several possible causes of this condition.
Hopefully, your greenhouses are now thoroughly cleaned so there is no leftover debris, organic material, weeds and "pet plants" that may serve as a source of pests and diseases plus thoroughly disinfested in preparation for the upcoming growing season.
Inspecting incoming plants
How a mix is handled can affect the air and water content of the mix. Compaction is an important factor to consider for plant root health when handling growing media. Air space that results in good drainage can be cut in half or even eliminated by compaction. To minimize compaction, containers, cell packs and plug trays should be lightly filled and the excess brushed away. The media should not be packed down, tamped down, or the filled pots tapped down on the bench several times, and the pots and trays should not be stacked directly over one another.
The payback on energy conservation is only 6 months to 2 years according to John Bartok at a recent Connecticut Greenhouse Growers Program.
Energy conservation is an important first step even if you are considering changing to alternative fuels. So, take some time to do a walk thru energy audit of your greenhouse operation and see web sites below for links to more information on energy conservation and renewable energy to assist in your decision making and planning for the future.
For more information: