Daylilies

I planted daylilies because I was told they were tough. I don't know what "tough" is like in other parts of the country, but mine are not tough enough for Las Vegas. They bloom every year in late May but only if we don't get an early hot spell. If we do, the daylilies quietly fold up their tents and die away for the summer. (The leaves, though not the flowers, come back in the fall.) This week and last week have been in the 100s, and this morning I noticed the beginnings of die back in the daylilies. It has been cooler in the past few days, however, so perhaps a few blooms will be spared.