Wax leaf begonias require low to medium fertility levels between 100 and 200 ppm N. Insufficient fertility results in an overall chlorotic (yellow) cast, stunted plant growth, and in green-leaf varieties, reddening of the leaf margins and interveinal spotting. Optimal substrate pH values range from 5.5 to 6.2. Substrate pH values >6.5 inhibit iron uptake, leading to symptoms of interveinal chlorosis on the upper leaves, easily distinguished in green-leaf varieties.
Read more at e-GRO (W. Garrett Owen, Josh Henry, Brian E. Whipker)
