I am very new to gardening and this year have gotten myself a 4 tier plastic greenhouse to see how I go , do I open it up during the day if the weather is nice??
Good advice , Mike. My 14 yr old nephew started with one of these last year. By autumn he wanted a larger greenhouse. He now has a 6 x 8 . I think he is a late developer. I started with a corrugated plastic 6 x 8 at 10 and had a glass 8 x 16 when I was 14. It's in the genes you know. Also a bit addictive. But then that's a better addiction than standing around on street corners up to no good.
It's advisable to open the vents (or door if no vents are present).
The plastic ones are often called 'blowaways' and certainly live up to their name. A fishing rod and 300lb line are great for pulling them out of neighbours' trees
Seriously though, if a glass greenhouse isn't an option on your property, the plastic ones are useful but rather high maintenance like scroggin and Mike Allen mentioned.
I have one of these located at the back wall of my house, as a temporary solution having recently moved to a house with no greenhouse . I loaded the bottom shelf with some roof tiles but anything weighty would work. The flat tiles mean I can still use the shelf. During the day, I unzip the door flap fully, roll it up to half way and peg/tie it to the nearest shelf. This way there is a bit of air flow but plants don't get too much sun or rain. It has worked for me so far without blowing away.