In order to see with my own eyes, what is the effect of mycorrhiza on the growth of heathers, I carried out my own experiment. I got the heathers from my friend, Jacek Wolski, and set them into 1-l containers approx on the 5th of July. Obviously I did not mycorrhizate some of the plants. After two months the difference of height reaches 100 per cent. No doubt, that not using mycorrhizal inoculants causes losses not only for the recipients, but also for the nursery men. I will present them after I work on them. Nevertheless, it is up to you to draw conclusions, taking into consideration also Phythophtora sp.