What does harden off seedlings before you planting outdoors mean?

I have been trying to grow Lavender Pansies. I haven't had any luck. I was wondering what harden off seedlings before planting outdoors means. I have went by the instructions on the back. I was wondering what this means.

What does harden off seedlings before you planting outdoors mean?
It basically means that you have to get your new little plants used to being outside. Start out slow -- take your new seedlings outside and place them in a shady or part shade area for an hour or two ... the next day, go a little longer, maybe three or four hours. Over the period of about two weeks, you should progressively increase the exposure time to the outside, along with the exposure time to the sun.



If you take your new plantings outside and plant them immediately, they will most likely die from shock from having been in a temperature and light controlled environment.
Reply:I take it you have planted your seeds indoors and they have been growing inside? If this is the case then you plants are going to be used to the warmth and won't really be able to withstand the temperature fluctuations outside. This will actually shock them and they will become sickly and could die. Hardening off your plants will allow them to get used to the outside temperatures more slowly. When it's nice enough, I put my seedlings out side for the day. I do this for a couple of days. Make sure they are in a somewhat sheltered (but sunny) spot since large rain drops could crush them. Once the night time lows remain high enough, you can start leaving them outside for a couple of nights as well.. See how they do. If they aren't wilted in the morning. then plant them in the containers/garden!



Cheers!
Reply:It means that if you grow them indoors or in a greenhouse, once your plants have grown big enough to plant, you need to place the pots or trays of pansies outside, so that they acclimatise to the outside temperatures.Do this for about 2 weeks then they will be safe to plant in the ground.
Reply:think about how you go about getting a tan.... a few minutes in the sun, back to the shade.... a little longer in the sun, back in the shade..... too chilly at night, back in the house!.... be sure that the time they spend outside is when and where you KNOW the sun either IS or wont be.... a sunburn on the little ones is a bad deal.....and make sure they don't dry out, since this is their first run-in with the drying air, too!....
Reply:It means that you get the plant used to being outside in direct sun and cool nights. Just gets them used to life outside so they don't shock and die if transplanted directly.