so far, the recently released plugin “Pollen Calendar” supports the Czech Republic, United Kingdom and United States. I am more than happy to include your country as well (if it is not the one already available), but it is a bit problematic trying to find the data for me if it is not in English. I am sure I would be able to understand it once I have the page, but trying to find such page is difficult.
If, therefore, you would like to see your country as well, then look at the plugin and look what sort of data it expects – basically a list of trees/weeds/grasses and their activity during the year. If you then find similar information somewhere, just send me a link and I will see what I can do.