or let it bloom and eventually die in the garden?
Really depends. If you have other houseplants indoors, you need to be aware that by bringing in garden plants you could be introducing pests to you otherwise healthy houseplants. And in personal experience, I've brought in glads once only to wake up the next day and find ants everywhere! If you are religious about pest control in your garden and check your plants over very carefully before bringing them in, then go ahead. A side note, keep in mind that as plants die (provided they didn't die from disease, infestation or fungus) they can be used as mulch, or composted.
Either way the result is death, so do both. Leave lots in the garden and pick a few for inside your home. Then you have the best of both worlds. Even better, dry some of the flowers to preserve them.
