another fertilizer question
hello everyone,, long story short: I have 13-13-13 and want to supplement the potassium, (or should I ?),, got some straight pot ash from the fertilizer co.
how much should I add? say if I use 1 cup of 13-13-13 , should I add 1 cup of pot ash? . or 1/2 cup? or what would be a good equation?
using it on in ground plants
Thanks in advance for any advice