Mr. Wilson's garden originally consisted of Dahlia bulbs. When Dennis sees them, he thinks they are ""sweet potatoes"" and after his bedtime, he ""secretly exchanges"" what is in his garden with what is in Mr. Wilson's garden. Dennis eventually raises the Dahlia bulbs & wins a 1st prize medal. After the garden judges see Mr. Wilson's garden, he is also given a medal.

Dennis learns Opie might leave because his bees have no honey. Dennis sprays prfume on Mr. Willison's flowers.

Dennis accidently steps on one of Mr. Wilson's plants and so he buys him a replacement and plants it in Mr. Wilson's flower bed. When Mr. Wilson sees it, he is convinced that his new miracle plant food that he invented works like a miracle.

Dennis is using numbers for a football play which is the combination to Mr. Wilson's safe, So Mr. Wilson and Henry get Dennis so confused that he forgets the combination. Then Mr. Wilson forgets it. Now they are in a real mess because Mr. Wilson has something very important locked in the safe. So Mr. Wilson tries everything including trying to hypnotize Dennis so he can remember the combination. He ends up hypnotizing himself and remembers the combination at last.