On Friday, January 5, 2018 at 3:09:00 AM UTC, brian mitchell wrote:
stuart noble wrote:

On Thursday, January 4, 2018 at 3:51:08 PM UTC, Jeff Layman wrote:
On 04/01/18 10:17, stuart noble wrote:
Based on my observations over the years, I intend to support my newly
acquired grapevine with 4" x 2" posts bedded in fine gravel. They
always rot at ground level, so maximum drainage for the first 6" or
so would seem to be the key to post longevity. Well, at least you can
yank them out easily enough when they do rot. Anyone any comments?
Metposts are not really approved of by the allotment establishment!

Have you considered cutting up an old railway sleeper and using that
instead of new wood? Some of those old sleepers, particularly those made
from exotic hardwood such as jarrah, are basically rotproof,even when
untreated.


--

Jeff

Sure, but not very practical for me, either finding such a sleeper, or cutting it to size!
There are plenty of silver birch in the local woods, and some are bound to be on the ground after the recent storms. Probably the most attractive option, if not the longest lived.

Not sure how it is in your immediate area but near to me in Wales
there are retail agricultural suppliers that sell pressure treated
fence posts for light stock (sheep) that are halves, flat one side.
They can be bought individually and are about six feet long with a
pointed end. To do the job you are doing I've got some of these and
sawn them into quarters but they could be left as are.

I think silver birch would rot very quickly, but are there any
overgrown leylandii you could acquire? They last well and are usually
straight.

Not very rural here in SE London, but some fencing suppliers list silver birch posts, so I suppose they must be reasonably long lasting and, in my case, available for free very close by. I have some old softwood floor joists but a bit brutish for the job in hand.