Is it silly to use a fan?

[Denninmi]

3. Not silly at all. It's S.O.P. in commercial floriculture.

You HAVE to have good airflow in greenhouses. Lack of airflow causes all kinds of problems -- allows disease organisms to grow, makes plants weak, floppy, soft, and tender as you have found out.

Even a small household fan set on low speed is enough in a small greenhouse is enough to harden plants. Basically, set it so that, at plant level, you can feel just a little air moving across the foliage. The plants don't need to feel like they're in a hurricane zone!

You may need to move the fan to different areas to allow all of the plants to get the benefit. Commercial operations use what are known as "fan jets" or "power tubes" that assure even air flow throughout the entire greenhouse growing area: http://www.greenhousemegastore.com/category/fan-jets-power-tubes

Be sure to use a ground fault circuit plug for safety when using fans or other electric equipment in damp/moist environments (any hardware will sell these).