Exhausted Bulbs - What To Do

How do we know whether the Tulip is dying down from exhaustion or just dead?

It's simple. Wait until the leaves are fully brown that you can easily pull them off from the bulb. Make sure you don't mistakenly pull the growing ones.

The green color for growing leaves.
The one that is not growing anymore.
You can make that comparison easily if you're growing more than one pots of Tulips. After pulling the leaves, dig out the bulb to check. If it's squashy and mushy, the bulb has died from rot. If the bulb is still firm, it means the bulb is just exhausted and ready for dormancy. (Go here to read further on providing dormancy or hibernation period for Tulip bulbs)

Why do bulbs get exhausted?
  1. They didn't get enough sleep, meaning, their dormancy period was too short and they're not ready for planting yet.
  2. They pushed too hard to grow, used up all the energy, but couldn't get enough light. Remember, Tulips grow prolifically in the heat of summer, where the sun is up as early as 6AM and down as late as 9PM. At least six to ten hours of bright light is needed for Tulips to grow.
  3. They spent more energy on growing leaves rather than growing roots. Now, this is tricky, but it happens all the time. This is also why it is encouraged to remove the basal skin before planting.