Vegetable Awareness

Gittel from Gush Shmonim asks:

I always thought that the kedushas shvi’is status
of vegetables was determined by the time of picking. If so, why do we still
have to be careful about vegetables now?

Your basic premise is correct. Vegetables picked in the sh’mittah
year have kedushas shvi’is. Those which grow by themselves (or are
planted in violation of sh’mittah laws, Heaven forbid) are forbidden
because of s’fichin. Both these laws should not apply to vegetables
picked in the eighth year. However, our Sages extended the prohibition of s’fichin
until the new crop of that specific vegetable began to appear on the market
(Tractate Shvi’is 6:4). Similarly, produce grown by non-Jews on their
land within Eretz Yisroel has kedushas shvi’is if picked before
this time, according to the Chazon Ish. Thus, once cucumbers sown and
picked in the eighth year start to become available, the prohibition of s’fichin
ceases to apply to all cucumbers picked in the eighth year. What was
picked in the seventh year still retains its former status. One must be careful
where one obtains canned pickles, etc. for a long time! Additionally, our Sages
gave a cut-off date for the end of the prohibition of s’fichin. From
Chanukah, all vegetables picked in the eighth year are permitted. Since people
no longer have sh’mittah in mind (when it comes to vegetables), we are
not concerned that people might come to use vegetables picked in the sh’mittah
year (Chazon Ish 9:13).