they were pre-bonsai stock that I put in cedar boxes 4-6 weeks ago. they've been doing great untill last week I started noticing more yellow & dry branches. The yellowing is from the inside out. If you stand back each tuft of green gradually fades from yellow to greeen, inside to outside. I've been cautious about not fertalizing untill well established. Now I'm afraid to fert. a sick plant. I've only given Superthrive twice, once when transplanted, & once recently. I just sprayed w/ a half-strength fert. last night. Any opinions on Superthrive?