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Bracken Weed Killer

Bracken Weed Killer

What is Bracken?

Bracken (Pteridium aquilinum) is a native British fern commonly found in woodland and heath land. It is tolerant of a wide range of soils and climates and has an extensive underground network of two rhizome types which makes control difficult.

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Is bracken harmful?

Fronds are poisonous to cattle and horses and harbour disease-carrying ticks and carry carcinogenic spores, however sheep and cattle normally avoid it.

Thick infestations of bracken can shade out all other plants

The fronds are most toxic at the newly emerged or crozier stage. The fronds become less toxic with age but it is important that bracken cut for animal bedding should have died back entirely. The rhizomes are also poisonous and are a potential hazard to pigs that may uproot them and to cattle when ploughing exposes the rhizomes.

Is Bracken Fern Poisonous to Humans?

Bracken is considered a human health hazard due to the carcinogenic spores. People who have spent the majority of their lives living around areas where bracken is growing are more at risk of getting certain cancers as a result of breathing in the carcinogenic spores. The bracken fern itself also provides a habitat favoured by sheep ticks which transmit Lymes disease which again can be an extreme risk to humans.

How to Control Bracken

What Will Kill Bracken Ferns?

Effective chemical treatment of bracken can achieve a 98% control level. Failures often result from poor follow up treatments and failure of the native vegetation to recover.

PG TopTip – Using a blue marker dye can help you to see where you have been when controlling large areas of bracken

Bracken Weed Killers

Treating bracken witAsulox

The specialist choice for bracken control is Asulox, which is a selective weedkiller meaning it will control the bracken without killing surrounding grass. For agricultural, forestry and amenity use, the selective weedkiller Asulox is best used when the bracken is at waist height or just below. Treat when the fronds (leaves) are at full extension using Asulox together with the non-ionic wetter IMPETUS. This reduces the surface tension of spray droplets on the leaf allowing the Asulox to work effectively.

Please see our Asulox listing for more information about the restrictions facing Asulox and the dates when it is available for use.

Follow up treatments:

Owing to the nature of bracken growth and the difficulty of spraying sheltered or uneven terrain, 100% bracken control is rarely achieved. Any bracken surviving should be sprayed as soon as it recovers to full green frond. This may be the year following the initial application but more likely the second year following initial application. If a programme of follow-up sprays is undertaken the bracken-free period will be greatly extended.
If no follow-up treatment or land improvement programme is carried out, re-spraying may be necessary within 5 years

Please speak to a Progreen Technical Advisor for information on how to control Bracken on 01778 394052 or email us [email protected]

Treating bracken with Roundup

There are several methods of application depending on circumstances. These include, application using a knapsack sprayer, a tractor-mounted or handheld Weedwiper and a tractor or ATV mounted boom sprayer. Both Roundup Proactive 360 & Roundup Provantage have full approvals for these uses.

Application rates of Roundup Proactive 360 are 5 L/ha or 25 ml/L water and equivalent rates of Roundup Provantage are 3.75 L/ha or 19 ml/L water. It is best uesd in conjunction with an adjuvant sticker: VALIDATE

Timings for control of Bracken control using Roundup are similar to Asulox – with spraying recommended as fronds approach full size and are fully unfurled in July/August, but before tip die-back. This window normally closes at the end of September depending on locality, altitude and season.

Treated fronds will die back within four weeks of treatment; future re-treatment may be needed. It is important that livestock are excluded from the treated area until bracken foliage has completely died back.

Equipment to use

At ProGreen we offer a variety of different types of equipment. When it comes to applying weed control to bracken there are a few options available. To start with a knapsack sprayer can be used with RoundUp ProActive, RoundUp Provantage and Asulox. A boom sprayer is also be a suitable piece of equipment to apply weed control to bracken especially if it is over a larger area. It is always important to check the product label to ensure that it has approval for knapsack or boom sprayer application. If you are unsure on what is the best method is best for you or which has approval, call us on 01778 394052 to speak with one of our technical advisors.


What willkill bracken ferns?

There are a few weed killers that are available to help you control a bracken problem, such as Roundup or Asulox. Asulox is however a specialist choice option and does have certain restrictions for its use – for more information on this take a look at the Asulox product listing, or if you think you would like more information give our technical advisors a call on 01778 394052.

Can you completely kill off bracken plants?

Unfortunately it is extremely difficult to kill off 100% of the bracken plant however, with effective chemical treatment you can gain 98% control over the bracken ferns.


To see more "By Problem" pages on how to deal with other plant/weeds, click here.

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