hmm i don't think it's N because then the whole leaf would be yellowing, not just the spaces between the veins.

I think it's Mg, and I am basing this on this plant problem guide- it's really good: http://www.icmag.com/ic/showthread.php?t=11688
dutch.lover Reviewed by dutch.lover on . nute def? hey guys, i cant determine what kind of def my lovely wonderberry is having. yellowing of the older leaves on the bottom starting from the tips. leaf tips are wilting down. Rating: 5