Strawberry runners help

This year I have made a troth, like a window box but about 5 feet long and have screwed it to my fence in the garden then planted it with 8 strawberry plants.
Now my plants are beginning to grow some runners that hang over the side of the troth.
I would like to keep the runners for the allotment but they have no roots and there is not any room to root them in the troth and to high to reach the ground.
Will they develop roots or any suggestions.
Thanks Reg
PS. there are 2 strawberry's so far, one for Pat and one for me....

I would try to find a spare table or bench or something that can sit against the fence underneath your window box thingie. Then you can put your 3" pots on top of that and peg the runners into them.

If they are new strawberry plant's, i find it better to remove all the runner's. I only pot the runners in the 2nd or 3rd year.