Monday, 4 December 2017

How to kill brambles

Is this our worst weed?

 Impenetrable jungle
Despite what you read, so called native plants such as blackberries, nettles and bracken make a greater and often more harmful ecological impact than much hyped alien weeds

Another native thug
It is a moot point how you define native. If a plant has been endemic since 1500 it is dubbed by botanists as archetype, the oldest category on offer and one which includes plants that have been with us for thousands of years. (Ironically if a plant arrives from seed carried by a bird and successfully establishes over just a few years it qualifies as native)
I suspect brambles have been with us for a very long time considering blackberries, my favourite fruit, must have been prized by ancient mankind

Merton Thornless was not around in the Stone Age
Rubus fruticosa has been no respecter of national barriers as it has travelled via the guts of mammals and birds.
The name Rubus fruticosa describes a very mixed bag of genetic material which has involved natural hybridisation between closely related species, subspecies, varieties and clones. Apart from its fertility it also often sets seed by apomixis a vegetative process that does not involve fertilisation although sometimes, and not uniquely to rubus, a process that needs the female germ cell to have had contact with pollen

A valuable nutritious fruit

This strong one year shoot will yield copious tasty blackberries next year
Man has selected from nature and by breeding has created superior varieties of blackberries. Indeed blackberries, raspberries and many other related berries have been crossed with each other to create a wide range of ‘hybrid berries’. Unfortunately some are more vigorous and viciously thorny than wild brambles! I love my vigorous high yielding thornless blackberry that yields big juicy black fruit. Most of the rest of them are too much for me.

Unfortunately not mine
Look what jumped out of my raspberry
A very pernicious weed


‘Bramble’ literally means scrubland and in the UK that means blackberries. It is an aggressively invasive weed, initially from seed. It then spreads vegetatively by strong growing stolons and root suckers and takes over disturbed landscapes both in the open and under light tree cover. It overwhelms abandoned allotments in just a few years

Brute force versus weedkillers
A single blackberry perhaps one year from seed should be physically removed. In contrast removing an old thicket is for the strong, foolish or impatient. It will surely work but only after pulled muscles and several severe scratches. You will not get it in one go and it will take several months removing suckers from roots you have missed. You will need to extract every last piece.
It is best to kill it by spray.

Chemical control
Spraying is much easier. It will take a little longer and you will need a complete growing season. Even more for myself when I take a feeble and gradual approach! Spraying might take longer to achieve final victory but in comparison the man-hours expended are tiny

Combine physical and chemical methods
If you can gain access to within a large clump and it is in late Spring, Summer or early Autumn spray at the first opportunity. This will be impossible if the brambles are eight foot high and extensive. Perhaps an overgrown allotment is small enough to spray from the edge?
For large expanses you will need to cut back first. Although a considerable chore you will eventually need to cut back dead stubble anyway. Cutting back is much easier than trying to dig it out! Use an industrial strength strimmer or wearing heavy gloves a strong hedge trimmer. You might need a sharp saw handy. 
Although I usually emphasise that you need to spray an intact top of perennial weeds to be effective, cutting back brambles might not be too detrimental to herbicide uptake. It is a moot point whether a woody head of an old thicket absorbs your spray chemical better than perhaps not less than foot long regenerating shoots

No use spraying old tops like these
I would spray these
Some of the literature says that if you spray fresh six-inch high cut back stumps immediately with a heavy drench of a strong solution of spray it works very well. As little as a year ago I would have claimed that this was nonsense. With my recent experience spraying the stumps of equisetum and reports on my post about Japanese knotweed similarly treated I am not so sure. I withhold any opinion!

Whatever variation you use and whatever chemical you chose you are extremely unlikely to completely kill the bramble in one go and it might very well take several applications. Let new shoots grow strongly before you respray. It is probably a waste of time respraying old yellow leaves.

Which weedkiller?
With the proviso that you will need to spray more than once there are several weedkillers that kill brambles very well. That blackberries are sensitive to glyphosate I know to my cost. I remember it only gently drifted on the strong scrambling shoots of several hybrid berries of an employer and they turned rather sick. Fortunately he never noticed! 

As it happens this discolouration was not herbicide damage 
Even this year a few early shoots on my raspberries turned yellow. Never control distant garden raspberry suckers by spraying! 
In that many of my readers will already have a five litre tub of 360gm/litre glyphosate they need look no further than using it at 1 in 40 or 50.

Brambles often invade grassland and MCPA bought as Agritox kills the brambles without harming the grass. So does its sister chemical 24D.
Use them at 1 in 50 and give a good drench.

Most brushwood killers do a good job and a chemical called triclopyr is particularly effective. I have used it as Grazon 90 ( Now called Grazon Pro) that is a mixture of triclopyr and dicamba. Absolutely superb although a litre costs nearly as much as five litres of the others - mitigated by its efficiency and that it is used at a third of their rate of dilution. It will also control almost all the difficult weeds in your lawn.
All the above are professional products readily available on the net but not at your garden centre.

A significant case study, Worsbrough cemetery


Twenty years ago this was solid with eight foot high brambles
I find this difficult to write as I am emotionally attached to this project started more than twenty years ago and one that I have now relinquished. 
I did not expect to tackle three acres of eight foot high brambles when I had offered to demonstrate my Bolton Percy techniques in the more public, and less weedy, parts of the overgrown cemetery.
We had unexpected help from the probation service when the ‘naughty boys’ came with their brush cutter strimmers! They were there for ten weeks. Normally after such attention and when no further action is taken the blackberries are as strong as ever two years later.
I felt obliged to continue. 

It was now possible to gain access and I waited until regenerating growth was nearly two foot high to spray with grazon which was very effective but challenged my budget. I reverted to using glyphosate and MCPA. It took eighteen months to get rid of it spraying several times.
No longer was it necessary for two men to take a couple of days to cut a swath through the brambles as a corridor to a new grave on the rare occasions the ‘old part’ of the cemetery was needed.
Although the brambles were beaten the area was charged with a huge number of blackberry seeds and for at least two years their germination was prolific. That was no problem as my garden weed maintenance is by regular spot spraying which has continued ever since. Of course the ground cover of desirable plants does most of the work now!


When ground cover like this is given a completely clean start from perennial weed it does most of the weed control for you
Sadly I have made my last visit to Worsborough. At seventy five it has become too much for me to hold back a four acre cemetery from nature! 


Plants such as this rhododendron give succour to seedling blackberries
Brambles even still appear from seed and have the constitution to infiltrate even my best ground cover plants and they also regularly emerge from large attractive clumps of Rhododendron ponticum and other thick growing shrubs such as six foot high hebes.
I have my doubts that the church has the resources and know-how to continue regular professional maintenance. I do hope I am wrong.
Without regular spot spraying (but not a scorched earth policy) I fear the brambles will return. Perhaps locals will welcome a season of blackberry picking. Even two before a dark shadow descends.

I like to think that the Worsbrough fisherman enjoys the view
I read somewhere that in olden times brambles were sometimes planted on graves to keep the devil away

Links
This was my post about spraying cut back mares tail and Japanese knotweed
The story of the Worsbrough fisherman
My articles about Worsbrough cemetery can be accessed by clicking on Worsbrough at the bottom of the theme column
If any new readers are inexperienced with glyphosate they will find the blog is littered with information - use the search box or theme column.

6 comments:

  1. One of our plots in particular was infested with brambles when we took ot on and it still emerges with stealth often amongst other plants. After years of wrangling a thorny specimen, I really appreciate our thornless Loch Ness. Last year we planted a black raspberry which looks very spiky so I hope that the fruit is worth it.

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    1. Some of the hybrid berries are lethal - and so vigorous! Hybrid vigour I suspect

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  2. Stunning pictures, Roger. When my time comes I would happily lie under that view. Not that I have anything against blackberries, but I am going to have to follow you advice on their control as they are growing like mad around me. Their thorns are lethal when they are at head height

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    1. Yes Jim, I know places where they scramble up to 4 metres high into tall hedge and hanging down are deadly

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  3. The cemetery looks such a wonderful place. Even without ever having been there myself, I can understand your attachment to it and your worries that it will not be looked after as well as it used to be.
    Near where I live, an unused rail track borders an area of fields where I regularly go for runs and walks. It is overgrown with brambles, much to the neighbours' pleasure - they all pick the fruit as soon as it is ripe, not leaving any for the walkers.

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    Replies
    1. Yes we do have a love hate relationship with them and so does nature. A newspaper has recently published a query as to why plants advantaged by their edibility to spread seed are so prickly.
      My worry about Worsbrough is that there will be no maintenance until it is too late. It needs to be maintained as a whole and it is not enough for people just to care for individual graves - although I was always grateful to those who do maintain family graves. Worsbrough is one of the few cemeteries where planting on graves is welcomed

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