Halacha Orach Chaim 225

Upon seeing a new fruit, one may and should recite a Shehechiyanu. The accepted custom is to recite a Shehechiyanu at the time one eats the new fruit.

A new fruit is defined as a fruit that is harvested seasonally, and is not accessible out of season. The reason for this is because seeing new fruit of a new season brings a person joy. Shevet Haleivi rules that if one does not experience the joy upon seeing these new fruit, a Shehechiyanu should not be recited.

If someone saw the new fruit several times without reciting the Bracha, he may still recite the Bracha at the time of eating. However, if someone forgot to recite the Bracha after eating a new fruit, the Bracha cannot be recited on the second time the fruit is eaten.

Pri Megadiim brings three different times for reciting Shehechiyanu. Ideally, the Shehechiyanu should be recited before the Bracha on the fruit. If the Bracha was already recited, the Shehechiyanu should be recited after partaking of it. If one recited the Shehechiyanu after reciting the Bracha, but before partaking of the fruit, it is considered a valid Bracha, and we do not view it as an interruption between the Bracha and the eating.

The Chazon Ish is brought in Archos Rabeinu to hold that the ideal time for reciting Shehechiyanu is after the Bracha on the fruit; however, if one ate from the fruit, the Shehechiyanu can still be recited.