Bunny, I almost never water them. They came thru our 6-month drought in 2005 with almost no supplemental water. This year we had no rain in June or July and then 17-inches in the first 2 weeks of August. They took it all in stride. For that reason it doesn't seem likely it's lack of water.

Mine in shadier locations did so much better, while the ones in sun needed a ton of water or they'd get crispy.