Have you put the soil in the pot per the directions? How big is the jar? I remember my mother had a strawberry jar and she loved it. If you can keep the plants healthy until the weather warms up a bit (I don't know what zone you are in and when planting is recommended), then put the plants into the jar, you should be OK.
I found a site with information about planting strawberries in a jar. strawberry jar instructions
I have a jar and being I want to put so much stuff on my deck, this would be perfect.