When you are growing young seedlings right now indoors or in a greenhouse or have plants which have been overwintering indoors, you should not bring them outdoors in one shot. If you do that, you might be very unpleasantly surprised, that you plants and seedlings give up on you just after one day of planting them.
Seedlings and plants need to gradually get used to the change of temperature, light, rain, sun and other outdoor elements. 
How to do it? Below I share with you the most common method.

– Begin the hardening off period 7 to 10 days prior to the date that you would like to plant your seedlings in their containers, pots or urban garden outside. 

– Day 1: Pick a mild day and around noon time, put your seedlings outside in a protected area, out of direct sun, just for few hours. Not too many hours, you just want to give them a ‘taste of the outdoors’! 

– Day 2 to 5: Increase the exposure to the outdoor and sun gradually, while keeping the seedlings and plants protected from any winds and colder temperatures. The wind can damage the stems of the seedlings or move them around so much that the roots will be loosened up. I suggest you put some stakes with the seedlings, you can use for example twine with chopsticks or the long wooden BBQ stakes for that. To protect them from the wind you can also put them for example in a carton box.

Do not keep them outside during the nights and also not during the day, when the temperature is lower than 10C. It will put your seedlings into ‘shock’ and it will have a bad effect on their growth and how much flowers and fruits they will generate.

– Day 6 to 10: Increase the number of hours your seedlings and plants during the day until you feel they can stay outside during the nights as well.

Even after this period, your seedlings and plants still might need some additional protection for winds and the strength of the sun. This especially when you enjoy your gardening on a (roof) terrace or balcony in a high rise. Just use your best judgement. 

Now, I understand it might be a bit of ‘nightmare’ to each time carry your seedlings and plants from the inside to the outside and vice versa. You might want to use a tray or even a small trolley if that works in your space. 

By hardening off your seedlings and plants properly and gradually you will ensure that you enjoy your seedlings and plants growing, flowering and generating fruits all summer long! 

I wish you a great weekend! Gera


Photo source: http://bit.ly/109ygWp