Since the Original Gold & Silver games the berries idea has change dramatically. In those games berry trees were scattered around Johto, but you could still pick them once a day. However this isn't the way it works anymore.

In Heart Gold & Soul Silver, you will find Berries scattered around Johto & Kanto, you can get them as gifts or you can find them with the itemfinder. However, there is no loamy soil in these regions for you to plant the Berries like in Hoenn. There is a new key item called the Berry Planter. With this Key Item you get four pots to grow Berry Trees without having to go backand check them, but like in Ruby & Sapphire you will have to keep an eye on them.