Our research on the use of slow-release biodegradable fertilizers were applied to Petunia hybrida seedlings of the variety “White Surfinia”. Thus after 10 days subculturing procedure was to apply fertilizers containing NKP24 biodegradable and made in the form of sticks and granules with six concentrations of starch (5%, 10%, 15%, 20%, 25% and 50%) quantaties (4-5 grams/ 1 pot). For each pot with of 8 cm diameter, we prepared a mixture of peat and garden soil in a rate of 1:1. During the vegetation periods, morphological analyses were made regarding the development of Petunia hybrida, cv. “White Surfinia”plants: the length of shoots and number of shoot. Average values recorded from morphological determinations after 1 month of starting experiments on biofertilizers influence on growth and development the seedlings of Petunia was demonstrated that the optimal variant was the fertilizer V5 with -25% WF (wood flour) to 50% concentration of biofertilizers NKP24 (for both form of sticks A-big and B-medium ) and for fertilizer form C- granular the V6 variant with -50% concentration of biofertilizers NKP24, the petunia stem was recorded maximum of 58.92 cm length .The research is part of an international project FP7/2008 with the title "Forest Resource Sustainability through Bio-Based-Composite Development" – FORBIOPLAST. Multiple aims of FORBIOPLAST project are the valorization of forest resources for the production of bio-based products