Generate a question that has the following answer: 40 years for the following movie plot: Dennis Mitchell is a five-year-old boy who lives with his parents Henry and Alice, and is the bane of next door neighbor George Wilson's existence. Because of his trouble-making but unintentional behavior, his parents often struggle to find suitable babysitters to deal with him. On one night, they manage to get one named Polly and her boyfriend Mickey to babysit him, but repeated doorbell pranks from him push the two too far (not knowing he is behind this), and they end up pulling a prank on George when he rings the doorbell to scold Dennis after finding paint and wood in his food in an earlier incident. While all of this and the rest of the events in town go on, a burglar named Switchblade Sam (said name not mentioned in the film, only in the end credits) arrives in town and begins robbing houses, as well as striking fear into the children that he meets. Dennis' parents are both called away on business trips at the same time, and when everyone they know refuses to look after him, they turn to George and his wife Martha (who loves Dennis and sees him as a surrogate grandson) to look after him. George is further irritated by him spilling bath water on the bathroom floor, swapping chemicals, and bringing his pet dog, Ruff, into the house for a while. All of this is happening around the time the Summer Floraganza, a long-awaited event, is scheduled to happen. As a longtime member of the local garden club, George is chosen to host it. He is excited to have this honor, as he has been growing and nurturing a rare plant for forty years. After growing for the said length of time, its flower finally blooms, only to die several seconds later. Alice gets stuck at the airport due to a storm, thus forcing Dennis to stay with the Wilsons for an extra night, which coincides with the unveiling of the plant and its blooming to the members of the garden club. While that is happening, he is sent away for causing trouble (namely overturning the dessert table when he pushed a black button, which he found out opened the garage...
How long does it take for George's plant to grow before it blooms?