KanjiJLPT N4
Renew

grow late, night watch, sit up late, of course, renew, renovate, again, more and more, further

Mnemonic

One withered field desperately needs to renew itself. You reject every dead stalk, ripping them from the soil. One by one, fresh green shoots replace what you reject, until the entire field is reborn — fully renewed.
Additional thoughts
Picture yourself standing in a single dying field, tossing out dead plants with both hands. Each rejected stalk instantly sprouts a green replacement. The act of rejection IS the renewal — clearing the old makes way for the new.
Quick recall
One dead field is rejected stalk by stalk to renew it completely.

Details

The keyword for 更 is renew. This kanji conveys the idea of changing, replacing, or starting fresh by doing something over again. It carries the sense of renewal or alteration, suggesting that something is being updated or made new. It can also imply "furthermore" or "even more," extending the notion of going beyond what currently exists.
On'yomi
こう
Kun'yomi
さら、さら.に、ふ.ける、ふ.かす