In June, they started dropping leaves again, and the leaves left on the plant sometimes had brown around the edges. We have just come back from a honeymoon after three weeks and have discovered that most of our weigela have dropped all of their leaves. Some of the plants have new leaves sprouting at the base of the stems. Others look completely brown and crispy (i.e. dead).

Our weigelas are planted in full sun and have drip irrigation watering them at a rate of one gallon every other day. The summer weather has been unseasonably friendly (that is, not 100 degrees and dry all summer like we usually get). We sprayed for insects and fungus twice in June, the last time just before we left.

Any thoughts?

In any case, the only times that I've seen my weigelas do what you describe (leaves with crispy edges and/or partial defoliation), was when it was unusually hot and/or they needed water and at this point, I have one that is 8 years old in an 18" container that I *know* is root bound. But I water often, mulch, and fertilize, and it is doing fine.

It is possible that although you are drip irrigating, the root mass may be so tight that the water barely penetrates the center of the root zone. When you planted, did you make sure you broke the root ball up? Also, are they mulched? It might be better to water them less frequently but for a longer time, in order to encourage deeper roots.