I had the same problem earlier this season. I tried to feed with Big Cannahuna nutes which you have to mix with water,I couldn't feed because of to much rain.
I agree with ernesttwwg, I started to top feed with Gaia Green 4-4-4 during veg. and 2-8-4 power bloom for the flowering stage, then all you have to do is water after the rain stops. Plus I add a little cal-mag and an oganic bud booster a couple times a week, plant is very happy and healthy.
Luck with your plants!!!