First, consider whether control can be done using non-chemical means such as digging out or covering with mulch. Where these methods are not feasible, chemical controls may be needed.
Bracken is difficult to control, even for farmers and landowners. It can be checked by traditional methods, such as cutting, crushing and burning, but these are labour-intensive and do not kill the underground stems, from which the bracken can regenerate rapidly.
In small areas, try persistent hand tugging to remove emerging fronds, or crush new growth while still soft and tender. If carried out over several years this can progressively weaken and eradicate an isolated infestation. In larger infested areas, making two cuts per year for at least three years may considerably weaken the bracken but is unlikely to eradicate it.
When pulling out bracken stems, wear heavy gloves, as robust stems can splinter and cause serious hand wounds.
Choose an appropriate weedkiller by reading the label to ascertain the ingredients. Contact weedkillers and systemic, glyphosate -containing weedkillers have no persistence in the soil. Residual weedkillers persist in the soil for several weeks or months and can move deeper or sideways, leading to possible damage of underlying plant roots.
Systemic weedkillers containing glyphosate
For gardeners, glyphosate is the most effective weedkiller available for controlling bracken. Try tough formulations such as Scotts Roundup Ultra, Scotts Tree Stump & Rootkiller, Bayer Garden Rootkill Weedkiller, Bayer Garden Super Strength Weedkiller or Doff Maxi Strength Glyphosate Weedkiller. For best results, apply glyphosate in mid- to late summer (July-August) when the fronds are fully open but before the bracken starts to turn brown in autumn. Spraying younger, smaller fronds is much less effective.
Bracken is quite large by midsummer, so it may be difficult to spray the bracken without also spraying nearby garden plants. Try pegging them out of the way and protecting them with plastic sheeting.
Inclusion of a weedkiller product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener.
Weedkillers for gardeners (Adobe Acrobat pdf document outlining weedkillers available to gardeners; see sections 4 and 5)
Chemicals: using safely and effectively
Chemicals: using a sprayer
Chemicals: using spot and broad-scale weedkillers