Fuzhou's nickname 榕城 ('Banyan City') dates to the Northern Song, when prefect 张伯玉 (Zhāng Bóyù) ordered citywide banyan planting in 1073 — the trees thrived, and Fuzhou's single-character abbreviation 榕 stuck for nearly a millennium.
memory
木 (wood/tree) radical + 容 (róng, 'to contain'). Banyans famously grow aerial roots that drop down and form pillars — eventually one tree contains an entire grove. The 容 phonetic doubles as a hint to that 'containing' nature.