go to seed
Verb
Meaning
(of a plant) To pass from flowering or ripening to the formation of seeds.
(figuratively, by extension) To deteriorate; to decline into an unkempt or debased condition.
Source: en.wiktionary.orgSynonyms
Examples
Between now and the first of May, most dandelions go to seed along the 40th Parallel.
It caused several of our cool season crops like lettuce to bolt and go to seed.
To meet this ambitious production target Shahabedine said that US$ 120 million would need to be invested in the agricultural sector, of which more than US$ 10 would go to seed imports.