What kind of jasmine? Many plants go by that name -- is it a jasminum sambac, a cestrum nocturnum, or a murreya paniculata, for instance?

I'm guessing it's the first, so:

Regular fertilizing of a bloom-booster or fert for acid loving plants will keep it going and keep the leaves from turning yellow from chlorosis.

You can try pellets, like osmocote, if you don't want to deal with adding fertilizer to your watering can.

Just remember, less is better than too much, even with a hungry feeder like jasmine!

Jim