Abstract: Method of protecting plants from both fungal organisms and mites in the same treatment in which there is applied to the plant an amount of one or more of selected tricyclopentyl tin and tris(cyclopentylmethyl)tin compounds, which amount is sufficient to provide both antifungal and miticidal protection but is less than a substantially harmful phytotoxic amount. Counter ions in these compounds which are suitable include hydroxy, halo, oxo, thioxo, alkyl- and aryl carboxylate, thiocyanato, diloweralkyldithiocarbamoyl and diethoxyphosphinothioylthio.