The European Commission presented its proposal for a new regulation regarding the use of organic and waste-based fertilizers in March 2016. The new regulation could facilitate product development, production and wider use of organic fertilizers.

This thesis was commissioned by a Finnish growth media supplier. The commissioner´s aim was to bring a new organically fertilized growth medium to the market. To bring new products to the market and developing them, it is provided to test the growing media in the field conditions. The media mixes under test were peat-based, limed and with a basic fertilization. The container experiment included 6 different kind of media mixes. 4 of the mixes were organically fertilized and 1 was inorganically fertilized. The control-mix was a limed but not fertilized media mix.

The test plant in the experiment was the French marigold (Tagetes patula). Flowering, roots, dry weights, pests and diseases were measured and observed. Also, the electrical conductivity and the water content of the medium were measured. The data of average temperatures and rainfall during the experiment was gathered from the weather station in HAMK Lepaa.

The highest mean values in roots´ amount and composition and in dry weights were on the treatment number 5 which was inorganically fertilized. The second highest mean values in roots and in dry weights were on the treatment number 3 which was organically fertilized. Based on the results, the treatment number 3 could be recommended for the use of consumers and for professional use. Media mix should be used with annual bedding plants which have the same requirements for nutrition as French marigold has. In professional use, the media mix could be used on container-grown annual bedding plants in public areas. In commercial annual plant production the media mix could be used on hanging pots and containers which are usually fertilized with slow-release fertilizers.