Weeds competing with seedlings of trees for nutrients, moisture, light and space, drown out their growth in nurseries and forest crops. Currently, in forestry, weed control is mainly carried out in forest nurseries, less often during the preparation of the area intended for afforestation, but sporadically in forest crops. The most important species of weeds threatening seedlings of forest trees include Senecio vulgaris, S. silvaticus, Deschampsia caespitosa, Pteridium aquilinum, Agropyron repens, Calamagrostis epigeios and Equisetum arvense.
In Poland, herbicides have the largest share (about 50%) in the sale of plant protection products, but the scale of their use in forests is small, compared to agriculture. In 2012, 915 herbicides were registered in the country, out of which only 14 products (0.5%) were for use in forestry. In the years 1999–2019, 31 herbicides were registered for the protection of forest nurseries and crops, which included 13 active substances belonging to 11 chemical groups, of which 9 active substances have been used up to now. Most herbicides (15–16) were used in the years 2004–2006, the lowest in 1999–2000 and in 2014 (4 products). The most popular active substance has been glyphosate contained in 18 products.