I grow three neotropical blueberries: macleania pentaptera, macleania glabra, and disterigma rimbachii. For the past few months, the m. glabra's leaves have been looking a little chlorotic. New growth looks healthy, flushed with pink, but soon begins to yellow. Otherwise, it grows steadily. Like the other blueberries, it grows in a mix of fine-grade orchid bark, perlite, and some peat and LFS. I water with distilled water and it occasionally gets half-strength orchid fertilizer (urea-free 20-14-13).
Anyone know what might be causing this? bad soil recipe? wrong fertilizer or too little?