Boil the rose hips for 10 - 15 min. until soft enough to crush. Crush them and squeeze through cloth, to make juice. For every 4 cups of juice add one box of certo and bring to a boil. Add the 1/2 cup of lemon juice and 5 cups of sugar (1/2 tsp. of marg to prevent foam). Buing to a boil and boil hard for 2 min. Remove from heat and pour into sterilized jars and seal with caps and rings. The jelly has a wonderful flavor and is the consistency of liguid honey.