Originally describing plants, this phrase is extended to describe anything neglected. The vacant house has run to seed without anyone to look after it.
Pro Tip 2/3
Neglect Context
Use this phrase in contexts where neglect leads to a state of overgrow or disrepair. The once beautiful garden went to seed after the gardener retired.
Pro Tip 3/3
Natural Process
This phrase can emphasize a natural process occurring without human intervention. The wildflowers in the meadow go to seed every autumn.