What plant in the original game is used to wake up sleeping mushrooms?

The plant used to wake sleeping mushrooms is Coffee Bean.

Coffee Bean is an instant-use plant in the original Plants vs. Zombies. When planted directly on a sleeping mushroom, it wakes that mushroom so it can function during a daytime level. This lets players use plants such as Fume-shroom, Hypno-shroom, Ice-shroom, Magnet-shroom, and Doom-shroom outside their normal nighttime setting.

The mechanic is part of the game’s day-and-night contrast. Mushrooms are generally inexpensive and powerful for early nighttime defense, but most of them sleep during the day. Coffee Bean provides a way around that limitation, though using it costs additional sun and occupies a plant slot, so waking every mushroom is not always efficient.

The wrong options are all mushrooms rather than the wake-up tool. Fume-shroom attacks with penetrating fumes, Puff-shroom fires short-range spores for free, and Scaredy-shroom attacks from a distance but hides when zombies approach. Coffee Bean is the only listed plant whose defining role is awakening sleeping mushrooms.