Cold frames

Pta55

I Have a four tier plastic mini greenhouse can I use it as a cold frame particularly for hardening off. Pta1955

pr1mr0se

That's how I use mine - I call it a vertical cold frame.  The advantage, of course, is its small footprint, but if there is a sudden late frost, it is worth popping a bit of fleece over anything a bit extra exposed (at the top, for example).

Fairygirl

Just bear in mind - they're good for keeping rough wet, weather off, but they don't give the same protection as glass, and they heat up incredibly quickly, so make sure you open it up, even on cloudier days 

Pta55

Thank you, I will give it a go. I do have the plastic cover but would think it will be too hot as Fairy Girl said. Fleece seems a good compromise. Thank you. Pta1955

Pta55

Just thought, which is the best aspect for it to face. Pta55

Fairygirl

I wouldn't have it in full sun. 
If it's warm, you can put the plants out  in the open, but again, sheltered from excessive heat and wind. Then put them back in at night until acclimatised.
The length of time that takes, will depend on the type of plant, and their maturity.

Normally, a cold frame can be in a sunny, bright spot, but it depends how it's being used and when. 

Pta55

Just want to use it to harden off annual flower plants and bean plants for this year. Will look at a proper cold frame later in the year. Pta55.

Fairygirl

Just a sheltered  spot is fine then. Extremes of weather is all they'd need protected from for a while 

Keep it well opened up on warm days too.