Ready when ripe
Kaafebaloos are grown on the surface of their planet. The underground roots sprout new growth that will eventually grow up to be a Kaafebaloo. Grown in patches this species will gradually develop their senses and their knowledge given via the guardian. The guardian will roll over the patches of new growth in attempt to pick them up to begin the process of transmitting all the past and current knowledge of the species. After some time, the new growth should be matured enough to be integrated into society.
Lifespan
Kaafebaloos live a long life compared to us humans - most Kaafebaloos live around 450 Earth years old. An estimate of their lifespan is between 400 and 600 Earth years. A good way to put this into perspective, it would take Kaafebaloos about 8-10 years to arrive to our planet. 10 years is a very large part of a human life however to a Kaafebaloo this would feel like a long holiday trip. It would only take them around 4% of their lifespan to do a trip to and back from Earth - on the other hand it would be like 20-30% of a human's lifespan.
The last stage of their lifespan is being one of the many elders, lots of elders become guardians. Eventually the elders will start to show signs of rotting and at this moment the job of the submerger is required to submerge them under the ocean.