Phytophthora cryptogea and Phytophthora citrophthora were isolated from rotted stem base of Forsythia intermedia cv. Minigold and from substratum, respectively. Additionally Botrytis cinerea and Fusarium spp. were often isolated from diseased tissues. In the laboratory trials P. cryptogea from F. intermedia colonised and incited disease of leaf blades and stem parts of all tested cultivars.The species caused necrosis development of leaves and stem of Ligustrum vulgare, Sambucus nigra and Syringa vulgaris after 3 days of inoculation. The isolates from 7 different host plants colonised (except from Sempervivum arachnoideum) leaves and stem parts of F. intermedia cv. Minigold with the fastest spread of necrosis on plant parts inoculated with isolate from forsythia. P. citrophthora from substratum colonised leaves and stem parts of 5 tested cultivars with the quickest spread of necrosis on cv. Goldzauber and Spectabilis.