Question
We have a very healthy watermelon plant on our balconey however it is taken a lot of space  are we able to prune the plant, it will it hurt it

Answer
Unfortunetly, watermelons are not your best choice for a small balcony vine. The standard watermelon will have vines that reach from 8 to 10 feet. A little shorter in a container. There is a dwarf watermelon that gets about half that size.
The problem with pruning your monster is that you are cutting off the fruit. The fruit will be on the long vines, where the flowers appear. It will not kill the plant to prune it. It will still continue to grow just as it did before you pruned it. It will not stop growing until it freezes. The only thing I can think of, is having it grow up, if you can. I have seen this done. It will take a good support to hold the heavy mellon and vine. A heavy trellis or metal railing will work.The idea being that it will get it up out of the way and it can still grow and produce melons. I am sorry I don't have a better solution.

bakerplanter