Fusarium oxysporum f.sp lycopersici is a fungal pathogen that cause wilt with a resultant yield reduction of about 45%. Seven ash samples from organs of some tropical plants were screened for their abilities to inhibit mycelia growth of F. oxysporum f.sp lycopersici in vitro. Ash sample had high inhibitory effects on the growth on the F. oxysporum f.sp lycopersici in the following decreasing order Xylopiaaethiopica > Azadirachta indica > Elaeis guineensis >Ocimum gratissimum > Chromoleaena odorata > Delonix regia > Magnifera indica. X. aethiopica ash applied at 15% concentration recorded the highest inhibitory effect of 87.5% on the growth of F. oxysporum f.sp lycopersici . This study demonstrates the potential of ash tropical plants in the control of F. oxysporum f.sp lycopersici on tomato.