The invention relates to a method for providing plants and/or plant parts with an identification label, comprising contacting the plant or plant part with a product, comprising one or more types of tracer molecules, preferably fluorescent tracer molecules, and allowing the plant or plant part to take up the tracer molecules either inside the plant or plant parts or on the surface thereof. The invention further relates to products for use in the method and plant and plant parts treated with the method and to methods for identifying plants or plant parts carrying an identification label.