Explain: “And years that fade and flush again”.

The poet tells us the universal running of the time.  The lines “YEARS WILL FLUSH AND FLUNG AGAIN” tells us that the tree would produce buds and seeds in future and the time would pass silently but the tree would remian there through the seeds producing new trees.

“Years that fade and flush again” refers to the universal running of time. The poet has mentioned it when talking about the long-lasting benefits of plantation. He describes a tree as the “seed and bud of days to be / And years that fade and flush again;” It means that the tree planted at present will bear flowers, fruits and seed for a long long time in future, for years to come.

A tree planted today will not only reap benefits for present but also for the future generation.

It means that even if the old tree withers away, the seeds that it produces will grow into new trees.