After talking to the man inside the house to start the mission, simply head outside and gather the beehive plants in the yard. Return them to the man then head outside again and gather x3 Heliconia plants. Head to the hill to the north and gather the key Heliconias there.
Deliver it again to the man and he'll send you off to gather Screw Pines this time. Head to the location and gather the plants again. Finally hand them over to Alfie to get your reward and to unlock the Nature Boy recipe.