These summer-blooming bulbs spread by bulb offsets, advises Missouri Botanical Garden. This division gives your garden a naturalized look, but eventually, they will become overcrowded and you will need to dig up and thin the bulbs so they can continue to thrive.

Can lilies spread?

When cared for and left to themselves, lilies will quickly spread out and can fill a garden bed over the period of a few seasons. When a gardener intervenes to propagate them, the process is accelerated and new plants can be strategically and deliberately placed. Early fall is a good time to propagate lilies.

Do surprise lilies bloom twice a year?

Although most will put up leaves their first spring, sometimes nothing emerges until the spring after that, and they virtually never bloom until their second or even third year.