The Hidden Garden is the twenty-third level in the Pikmin 2Challenge Mode. Only two Bulbmin are available. Being that there are no harmful enemies in this level, a pink flower is inevitable upon winning, unless Pikmin are left unplucked.
The Key is located inside a Skitter Leaf. There are many Queen Candypop Buds which can be used to increase your Pikmin amount. Most treasures are hidden inside pipes or inside other Skitter Leaves. Also note that this stage is similar to the fourth sublevel in the Shower Room with a few minor changes.