
The period during which Shmittah restrictions apply to different fruit and vegetables is shown in the chart HERE from the London Beth Din.
Please note that the dates given are for fresh produce and do not include frozen, tinned or dried products. These have a long shelf life and require a reliable hechsher.
Outside the period when Shmittah restrictions apply, terumah and ma’aser should be taken.
{Matzav.com}
The post does not make clear whether this is for people in Eretz Yisroel or the rest of the world also and it should have because it reads as if to apply all over the world. In general the poskim say that fruits and vegetables in America have a rov that they come from places other than eretz yisroel. So the issur of shmita in America is only on those items that clearly are from eretz yisroel.