Give the rarest valid answer you can for each prompt. Obvious answers water your plant a little. Rare, specific ones water it a lot. Get all seven rare and your beanstalk breaks through the clouds.
7 prompts per run, 15 seconds each. The obvious answer everyone thinks of first barely waters your plant. A rare, specific, correct answer can water it fully — up to 1000 points, which is 1/7th of the way to the clouds. Get all 7 at max rarity and your beanstalk bursts through the top.
Run complete.