These may look like cute little flowers but they have been nothing but a thorn in my gardening side for the 5 years we have lived here. They are biennials that reseed themselves. To remove them you have to dig up the grass like foliage including all the bulbs. Some of these bulbs are the size of an onion, but most are pea size and smaller. I have spent the afternoon cleaning them out of my shade garden and will work on the other garden this weekend. Here is a large patch in my shade garden. Each one of these bunches has a large bulb and 10-20 smaller bulbs that need to be removed.It is actually pretty easy to dig them up, most of the bulbs are clumped together and very close to the surface. Some do require a little digging, usually 8-10 inches deep to remove the bulbs.
I read that to keep the star of Jerusalem from becoming invasive in your garden, clip the seed heads from the plant before they ripen. This has not worked so far, but hopefully once I get them thinned out they will be easier to control.
I have to say that they are very beautiful when they all bloom, which I allow in one large area of the yard. After they are done blooming we just mow them off. Here is my niece Miss AllieCat a couple years ago in the large patch of Jerusalem Star.