Thursday 2 December 2010

Blackthorn. (Prunus Spinosa)

I thought I'd share my thoughts on some of my favourite native UK timbers I like to work with. Starting with Blackthorn. Prunus Spinosa translates as 'Spiny Plum', it has various local names in the UK such as Sloe in English, and Slae in Scots. It is the original indigenous Plum which, crossed with the Cherry Plum, is the parent of our domestic Plums, Damsons and Greengages. Blackthorn is a true native tree, with some fossil evidence from the last interglacial period.

The Latin name is very apt . the numerous thorns are hard and as thin and sharp hypodermic needles. They were used by country women as pins for sewing. Extreme care must be taken when handling Blackthorn as the thorns can cause serious infection if they become embedded in flesh.

From ancient times Blackthorn was used as hedging around livestock enclosures due to its predator proof habit of forming dense thickets. Nowadays, it is less common than Hawthorn due, in part, to the fact that Hawthorn grows readily from seed where as Blackthorn more readily reproduces through suckering.

The easiest time to tell the 2 apart is in early spring when the unique white blossom of Blackthorn comes out weeks before Hawthorn and before its own leak buds burst open. The bark varies regionally and with age; from light brown to a deep black with ruby brown hues in between. The leaves are small oval shaped and 1 1/2 " long, turning yellow before dropping in Autumn. In Autumn the round plums ( Sloes), up to 3/4" in diameter, grow in bunches along branches.

The wood is possibly best known for making walking sticks and the fabled Irish club- the Shillelagh. The side branches being cut back to leave the that give the finished stick shanks their character:


As you can see from my previous post the Sloes can be used to flavour Sloe Gin.
Where I live in the north of England, Blackthorn is quite ubiquitous so I have worked extensively with the timber. It is typical of most fruit wood being hard, close grained and hard wearing. The wood has a lovely orange glow and the the heart of older wood becomes tinged with green/brown which makes a nice contrast.

If you intend carving treen from Blackthorn I would recommend removing the bulk of the material , close to the finished design, as possible whilst it is still green and easy to work. As it dries, the wood hardens severely to a hard plastic like consistency. The wood has a beautiful polished surface direct from a sharp edge tool, once seasoned. Here are a few examples of items I have carved from Blackthorn.





The 2 caddy spoons just below the knife handle with the orange hue are Blackthorn.

Hope this is useful.







4 comments:

  1. Indeed it´s useful, got a blackthorn for a staff recently.;-) Hung it up (sealed the ends) to dry and straighten. What I found out is that it cracks relatively easily. Would you recommend sealing a carving with some glue to dry? I have no possibility to dry it outside, so have to do it in the attic, where it is quite warm (quite obviously the reason my first try cracked, having not sealed it). I left the bark on it to dry.

    Thanks for your thoughts!

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  2. Hello and thankyou for commenting. With regards to seasoning a Blackthorn shank/staff, I think the most critical factor is when to cut it in the first place. If it is cut whilst it is heavy in sap, not only is there a greater risk of the staff cracking through rapid moisture loss but also the bark becomes wrinkly and can even detatch from the wood. So cut the shank whilst the tree is dormant in winter. I do indeed seal the ends of the staff with PVA to slow down the rapid moisture loss through end grain which causes 'shaking'. I have loads of Blackthorn shanks I cut last winter and none of them have cracked. I have stored them in a draughty shed with no heating or windows, so the differential moisture content of the timber and circulating air is not too severe. I would have thought an attic would give the opposite conditions - being warm and very dry, so maybe this is where the problem lies.At least it is out of direct sunlight, which causes cracking. With carvings, the principle is the same really- creating conditions where the blank is prevented from rapidly losing moisture through end grain because of a severe differential in moisture content. I usually store a carving piece in a plastic carrier bag with some of the wet shavings I have produced to keep things evenly moist. This works fine but beware that mould can form and badly stain some timbers if the piece is left like this for too long. Wille Sundqvist recommends smearing the carving with baked or boiled potato in between carving sessions- I can only presume this does the same job as the aforementioned PVA in blocking the severed end grain fibres.
    Having said all this air drying timber seems to be a black art to me, with many a hit and miss, even with logs from the same tree in the same conditions! These are just my own thoughts, no expertise in the field I'm afraid. I will post more about stick shanks and stickmaking generally soon as I am a member of a club with some excellent stickmakers.
    Cheers, John

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  3. Whoa, thanks so much for the load of advice, it has given me new insights indeed!! Have to get that book by Wille Sundkvist, there are many people advising me to it.

    It´s certainly a black art;-), but only because it is a natural material, and to me this is part of my fascination and joy in working with wood...

    Keep up the great work!;-)

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  4. I've been trying to locate some blackthorn turning blanks and knife scales for gifts for our fire department pipe band. Can you point me in the right direction or can you help out? I am in the US.

    Thanks,
    Brian

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