I don't like to use chemicals if I can avoid it after the sun goes down mix up 1 teasp liquid hand soap & 1 qt water and spray.............spray again if it rains. this is the safest method to use around birds. we had so much rain this year that it is effecting all the plants......be sure to have the best drainage for them.....sounds like you have a lot of plants.......so either replanted on higher elevated or do a drainage ditch so that the ground drains off the excess water. In the fall you could amend the soil, with mulch, old horse manure, some lime, hay or straw and cultivate it....when you rake finish the ground on a slight slant for good drainage.