A photograph would be useful to tell whether you have a version of Jasmine or Trachelospermum, both of which have variegated cultivars. If your plant is outside, it should not be fed at this time of year, and if its in the ground, a topdressing of something like Growmore in Spring is all it needs. Even with a houseplant, now is not the time to feed - they're usually fed monthly or weekly, depending on the feed, from early spring through till mid summer.