A farmer was courting a girl who lived in the city. She was beautiful, but very stupid. The beautiful girl from town told the farmer, "If you truly love me, you will shower me with beautiful things." So the farmer decided to plant flowers instead of crops, for that would impress his love. His brothers warned him, "If you do not plant vegetables, then you shall have none for when winter comes." He ignored their advice. When it came time to harvest, he presented the beautiful girl with his bounty of flowers. She was impressed, but the flowers soon wilted, and she moved on to other suitors. Meanwhile, the farmer was left without food in the winter. He then truly realized that you only reap what you sow.
Simple, as a fable should be, but very effective. A good Aesop indeed.
If you're in the market for suggestions, I'd say drop the 'But' and leave it at "He ignored their advice."
Maybe cut out the word beautiful from "...he presented the beautiful girl with his crop of flowers," to cut down on repetition of the word. By the same token, possibly change "...with his crop of flowers," to "his bounty of flowers," just for word variety. Minor things, of course.