[RichardA]

I bet this has been asked before but I could not find a reference. Can I ask please what experience anyone has had with preserving posts in contact with the ground. I have a supply of untreated sawn softwood 4 by 4 posts to build a frame for fruiting canes. What is the best way to extend their life both above and below ground.
Many thanks
R

[daisy1990]

I think any sort of wood treatment keeps the wood OK for ten years maximum.  I used metposts (available from garden centres) which are metal spikes that you drive in the ground and then put the posts inside.  They weren't cheap but I recently took some up after 13 years and the wood posts looked like new
Daisy

[Wild Pony]

We found using todays version of creosote called creocote and if you have some waste oil from an engine oil change mix some in and use an old bucket to put it in and put the end of the post in there for a few mins to soak then let them drain a bit before heaving them in, if its a permanent placing use post crete or similar for rigidity.

Hope this helps

[8doubles]

I think any sort of wood treatment keeps the wood OK for ten years maximum.  I used metposts (available from garden centres) which are metal spikes that you drive in the ground and then put the posts inside.  They weren't cheap but I recently took some up after 13 years and the wood posts looked like new
Daisy

Another vote for metposts, they keep the posts in good condition and are removeable/re-usable.

[corco2000]

if you have an ongoing unlimited supply of these untreated posts, I wont bother treating, if not cheapest is old engine oil, as mentioned. Putting drainage stones around post could also help.

[peapod]

First soak in treatment (oil etc) , then nail on damp course plastic (bought in a roll about 3 inches wide)and make sure the edges overlap so theres no gap for the earth to touch the posts

Ours are still going strong in the garden, and we expect them to for many a year

[Trillium]

I went the easy route and used metal post spikes:
http://www.click4garden.co.uk/index.php?getcatid=31

Got some on a good sale and I'm using them in quite a few places. Be sure to hammer it in straight (using a bit of waste wood) or it's a headache to deal with.

[8doubles]

I went the easy route and used metal post spikes:
http://www.click4garden.co.uk/index.php?getcatid=31

Got some on a good sale and I'm using them in quite a few places. Be sure to hammer it in straight (using a bit of waste wood) or it's a headache to deal with.

It helps if you make a vertical pilot hole in the ground with an iron bar or pipe just to make sure there are no large stones or roots to deflect the post spike.

[Slowgrind]

I'm not sure that old engine oil is safe around food stuff.
I think it may be carcinogenic check it out first.

[philskin]

fix some dpc around the post at ground level were the water lie.s this will help

[TheEnglishman]

I'm not sure that old engine oil is safe around food stuff.
I think it may be carcinogenic check it out first.

Yea, but you're not 'sploshing it all over', you're just covering the fence posts in them, like paint.   People creasoted everything wooden for many a year without anyone worrying about carcenogenic effect on foodstuff.  And I'm sure there's many an ambulance chaser looked into the statistics....


Something like dipping the ends in waxoil will work too.   

And don't forget to put a cap on the top of the post - that'll stop water getting down the pores.