Hinting is allowable, urging or instructing a lay person to damage plants is not.
I just came across this example from the Commentary on Dhp v 223
and remembered this thread.
Uttarā was the daughter of Puṇṇa, a poor man who worked for hire. While others were enjoying a holiday, Puṇṇa had to work because he was so poor. One day, the Elder Sāriputta, who had just arisen from spending seven days in absorption (nirodha samāpatti), wished to bestow a blessing on Puṇṇa. He went to the field where Puṇṇa was working and stood there gazing at a bush. Puṇṇa cut off a piece to offer tooth-sticks to the elder.