Based on " south acid and north alkali for Chinese soil, when garden plant originated from the south are transplanted to the north, they are often applied ferrous sulfate (also called iron fertilizer which is a indispensable element of these plants), especially for cycas and other acid plants. Ferrous sulphate could adjust soil PH and promote chlorophyll formation, so it can treat "yellowing disease" caused by iron deficiency. [Read More]