A lot of good advice so far in this thread.
Another thing to check is the ph of your irrigation water. Most domestic water supplies are ph adjusted to 8.5+. This is for health reasons, so that the water does not leach harmful chemicals from the delivery system piping. (I always laugh when I see specialty "alkaline" drinking water being sold at premium prices.)
This high ph irrigation water keeps most of my daylilies in a state of stress, and when the fall rains come, the clean, neutral-to-acidic rainwater releases all of the locked-up nutrients that I've been applying all summer, and I get flushes of deep green, healthy growth and a lot of scapes. Since you recently received some rain after a lengthy dry period, the soft growth you're getting might be from the same phenomenon.
Ken
East S.F. Bay Area
USDA Zone 9 - Mediterranean
