Warning: the drainage tray under my pots is doing more harm than good, argue with me
Left the saucers on under my 6 pots on the third floor balcony in Reno last summer and every single tomato plant got root rot while the ones sitting bare on the rail did fine. My neighbor swears the tray is what keeps the balcony from flooding and the plant alive, but I think it just holds rotten water against the roots. Who wins here, tray or no tray?