Plant diseases and pests can be introduced from outside the EU in living plants, plant products or other items which are carrying certain pathogens, or even in soil adhering to them.
The introduction of particularly harmful organisms, and also of plants, plant products, and other items that are, or could be, affected by such organisms comes within the scope of phytosanitary legislation. Certain plants, plant products, and other items may, in principle, only be imported if special requirements (such as a certificate, import inspection) have been completed.
The Customs administration monitors consignments into Germany from non-EU countries.
You can find information about phytosanitary protection on the websites of the Federal Ministry of Food and Agriculture (Bundesministerium für Ernährung und Landwirtschaft), the Julius Kühn Federal Research Centre for Cultivated Plants (Julius-Kühn-Institut - Bundesforschungsanstalt für Kulturpflanzen) and the phytosanitary authorities competent for your place of business.