Effectiveness of calcium, iron and zinc chelates as well as the urea on development of Fusarium oxysporum f. sp. callistephi, F. oxysporum f. sp. dianthi and Phytophthora cryptogea in vitro and in vivo was evaluated. Iron and zinc sulphates strongly reduced the growth of pathogens and formation of P cryptogea zoosporangia. Nutrition of carnation with calcium nitrate significantly reduced the spread of Fusarium wilt of carnation. Increase of substratum pH from 6.5 to 7.5 caused the reduction of the disease severity. Fe (EDDHA) used for Chinese aster nutrition significantly decreased the spread of Fusarium wilt. In the control of Phytophthora foot rot urea at dose 0.2 and 0.3% of a.d.s. strongly reduced the pathogens population and decreased the disease spread.