When is a Venus flytrap fully grown?

Question

how long does it live?

Answer 1

It usually takes a Venus Fly Trap between 3 and 5 years to reach maturity.  When it is fully grown, a flytrap plant is usually between 4 and 8 inches across.

Fly traps can live forever.  I know one person that has the same plant that he bought back in 1955.  The way the plants naturally grow, they divide and form smaller offshoots.  These offshoots grow into completely new plants, but they are genetically identical to the mother plant.  Thus, a plant can live forever by dividing.

If you have more questions, you should join the forum on my site and ask them there:

http://www.flytrapcare.com/phpBB3/

Answer 2

When it can feed itself...  Plant size is usually dependent on the available food supply, so if there's lots of flies buzzing around, then it may get big enough to pose a danger to a cockroach...