CC Ādi 9.9
bhakti-kalpataru ropilā siñci’ icchā-pāni
In many places devotional service has been compared to a creeper. One has to sow the seed of the devotional creeper, bhakti-latā, within his heart. As he regularly hears and chants, the seed will fructify and gradually grow into a mature plant and then produce the fruit of devotional service, namely love of Godhead, which the gardener (mālā-kāra) can then enjoy without impediments.