Perfect Strangers (1986)

S06E15 Little Apartment of Horrors

In the midst of winter, Larry catches a nasty cold, just like everyone else, except for Balki. To help, Balki's mother sends a special plant known for its healing properties, which quickly helps Larry and the others recover. Excited by its potential, Larry decides to cultivate the plant to make some cash. However, he soon discovers that making it grow larger leads to some unexpected and hilarious consequences.