Bracken ferns are common in most parts of the world. They are long stemmed plants that may grow from 1 to 6 feet tall. The fern spreads by rhizomes and reproduces from spores carried in the sporangia on the underside of the fronds. The leaves of the bracken fern are about 3 feet long and triangular shaped. The plant is very hard to get rid of especially if the spores have been released. Each fertile frond can produce 300,000,000 spores. Removal is important in farm areas because the fern is poisonous to horses and may kill them. Other livestock also exhibit signs of illness after eating the plant.
Cut or mow off the fronds before they develop ripe spores. The spores are brown when ripe and ready to disperse during the season. The bracken fern doesn't produce mature spores until its third or fourth season so it is important to cut off the young plants to prevent the spread of spores. Rake up and destroy the fronds.
Mow the second generation of sprouts that develop after you removed all the fronds. Consistently limiting the plant's ability to produce food via photosynthesis will eventually weaken and kill the roots and rhizomes.
Dig out the plants and rhizomes in smaller infested areas. The rhizomes will be rampant so considerable digging is necessary to get all of them. This is not practical in areas where there is a significant population of the fern.
Mix glyphosate systemic herbicide for bracken fern control. The herbicide gets into the vascular system of the plant and kills it from the inside out. Glyphosate is not selective so be cautious about what you spray and avoid applying in windy conditions which can cause the spray to blow onto un-targeted plants. Follow the instructions for amounts on the bottle and mix in a backpack sprayer with the recommended amount of water. Hand spray the mixture on each fern.
Summer is the most effective time for chemical treatment as the energy reserves in the fern are low. Chemicals work best after you have cut the fronds and are in stage two of the removal of the plant. Apply chemical herbicide on a day that rain is not expected.
Follow all the precautions listed on the herbicide label.