Ann B.
02-12-2002, 10:03 PM
This is a difficult subject, and there are varied experiences and opinions. I am sure that many will disagree with me. Yet, I would like to take the time to express my opinion and discuss my experience..
My greenhouse is made of treated wood frame with corrugated fiberglass. It is small, overcrowded and 15 years old, has withstood several hurricanes and floods, but I have to admit that no hurricanes as strong as Hurricane Frederick has hit our area since my greenhouse has been built.
My experience with different types of plastic sheeting has been the use of such plastic to enclose my screened in patio which faces north and is part of our main structure (roof) of our home. For many years, I used the multipurpose commercial and agricultural grade plastic sheeting which specified on the end of the box that it is clear and not for greenhouse use. In the summer, the lower sections which were left to prevent excessive rain received very little sun due to the shade of adjacent 50 year old pecan trees which are deciduous.
However, this plastic, although it lets some light in is not at all clear and is not very flexible. When I left some sections on for more than one year, it became brittle and shredded to pieces when I attempted to remove it despite the fact that it received very little direct sun.
Then, I discovered another plastic which rated for greenhouse use and is uv rated. It is available in very clear or less than clear (I am not sure of the proper term). It is also available in 3 ml or 6 ml. The 3 ml is gauranteed for at least 1 year, while the 6 ml is gauranteed for longer. I visited BWI in Semmes, AL to check out this greenhouse plastic and was demonstrated the stretchability of the non-clear plastic which is normally used on greenhouses in our area.
I chose to purchase a 3 ml 12' X 100' roll ($30) of the uv rated clear greenhouse plastic to replace the commercial grade plastic for my patio for 3 reasons. Number one, it let more light in during the winter when more heat and light is needed. Number two, I wanted to be able to use spline and Screen Tight tracks to install the plastic, thus allowing it to be easily removed in early summer and replaced in the fall. The third reason is because I was tired of being awakened during those cold, hard north winds which caused the agricultural and commercial grade of plastic to pop with a loud sound each time the wind blew hard. My bedroom is adjacent to this patio and only separated by sliding glass doors. To put it simply, I was tired of being awakened by these loud sounds.
For all of the above reasons, especially the uv rated ones, I recommend the use of uv rated plastics that are specifically made for greenhouse use and not the multipurpose plastic found in retail stores which states on the end of the box 'not for greenhouse use'.
As to shade considerations, there are many choices available. The nursery behind my house uses a shade fabric on the greenhouses they use for shade loving and less heat and sun tolerant plants. Most of theirs, however, is the non clear greenhouse plastic. There is also a special greenhouse paint that can be applied which will provide for less light and heat in the summer.
Of course, in our area, shade cloth is used for propagation to let rain come through, but prevent excessive sun light. This is not a greenhouse structure, but rather an arbor type structure with the shade cloth on top and on some of the sides (can be raised during spring and fall). This is a total different type of shade cloth use than that described for greenhouses.
Anyone else want to discuss their experience and knowledge of different types of 'greenhouse' plastics?
My greenhouse is made of treated wood frame with corrugated fiberglass. It is small, overcrowded and 15 years old, has withstood several hurricanes and floods, but I have to admit that no hurricanes as strong as Hurricane Frederick has hit our area since my greenhouse has been built.
My experience with different types of plastic sheeting has been the use of such plastic to enclose my screened in patio which faces north and is part of our main structure (roof) of our home. For many years, I used the multipurpose commercial and agricultural grade plastic sheeting which specified on the end of the box that it is clear and not for greenhouse use. In the summer, the lower sections which were left to prevent excessive rain received very little sun due to the shade of adjacent 50 year old pecan trees which are deciduous.
However, this plastic, although it lets some light in is not at all clear and is not very flexible. When I left some sections on for more than one year, it became brittle and shredded to pieces when I attempted to remove it despite the fact that it received very little direct sun.
Then, I discovered another plastic which rated for greenhouse use and is uv rated. It is available in very clear or less than clear (I am not sure of the proper term). It is also available in 3 ml or 6 ml. The 3 ml is gauranteed for at least 1 year, while the 6 ml is gauranteed for longer. I visited BWI in Semmes, AL to check out this greenhouse plastic and was demonstrated the stretchability of the non-clear plastic which is normally used on greenhouses in our area.
I chose to purchase a 3 ml 12' X 100' roll ($30) of the uv rated clear greenhouse plastic to replace the commercial grade plastic for my patio for 3 reasons. Number one, it let more light in during the winter when more heat and light is needed. Number two, I wanted to be able to use spline and Screen Tight tracks to install the plastic, thus allowing it to be easily removed in early summer and replaced in the fall. The third reason is because I was tired of being awakened during those cold, hard north winds which caused the agricultural and commercial grade of plastic to pop with a loud sound each time the wind blew hard. My bedroom is adjacent to this patio and only separated by sliding glass doors. To put it simply, I was tired of being awakened by these loud sounds.
For all of the above reasons, especially the uv rated ones, I recommend the use of uv rated plastics that are specifically made for greenhouse use and not the multipurpose plastic found in retail stores which states on the end of the box 'not for greenhouse use'.
As to shade considerations, there are many choices available. The nursery behind my house uses a shade fabric on the greenhouses they use for shade loving and less heat and sun tolerant plants. Most of theirs, however, is the non clear greenhouse plastic. There is also a special greenhouse paint that can be applied which will provide for less light and heat in the summer.
Of course, in our area, shade cloth is used for propagation to let rain come through, but prevent excessive sun light. This is not a greenhouse structure, but rather an arbor type structure with the shade cloth on top and on some of the sides (can be raised during spring and fall). This is a total different type of shade cloth use than that described for greenhouses.
Anyone else want to discuss their experience and knowledge of different types of 'greenhouse' plastics?