Thank you for a very timely thread!
I have landscape timbers that went in about 4 1/2 years ago, and last year I was already replacing broken posts. This winter I already have spotted three more that have broken. The pallet of remaining timbers is getting low so I have been wondering whether to get the same again 
or what would be better. The ground here is gravel (w/ lots of boulders - putting that fenceline in originally was a reeeeaaaalll stinker!) but we do get a fair amount of rain/snow.
I have used them in 2 diffrent locations/state 2 diffrent soil types.
While they may not hold up for the main fence that would get alot of pressure not only from horses but fence itself. For what you want they will work.
Cchewing if the chew it doesn’t matter if its granite they will chew it.
I have some who eat oak fence boards and other who won’t eat anything on the fence line ever.
I have used them as cavalletti ground poles and some are 12 years old, stay on the ground and are sound while my round rails rotted.
Guess Im lucky here in Vermont. Made a cedar post fence in 1980 which is still as strong as the day it was made. We cut spruce and poplar posts right here in the woods and use them to. Most of our dairy cow fence was spruce posts. Had to replace a few once in a while but not so much that it wasn’t worth the savings.
We used landscape timbers as fence posts for our Electrobraid fence (we did use regular fence posts for corners, gates, etc.) They were put in almost 5 years ago and have held up well.
This is the best picture I have that shows the posts:
I have used them around a riding ring with 2 boards on top - it worked ok I think because of the drainage and we dipped the bottoms before we put them in. If one did break, it wasn’t that hard to replace.
Would not use them for pasture though - not strong enough to hold up a regulare fence and have seen too many break if a horse leans on them - termite damage or not.
We used pressure treated 4x4’s - easy to put fence on and have lasted many years - just re-did (made it larger) a section - pulled up the old posts, repainted them and have used them as braces and for other fencing projects.
Nope
Previous owners of my place did it. They don’t hold up to the weather as well or horses bumping into them. I’m having to replace them one at a time.
Thanks for all theb advice. The reason it even crossed my mind is that the jump poles I have that are made of landscaping poles seem to hold up extremly well to the elements.
Ours are on year 4 and show no signs of rot or weakness. We put them 3 ft. deep with concrete in the holes. We have high water level and clay soil so it is wet soil a lot. No problems here.
We have electrobraid though and so the horses stay away from the fence. And I don’t have any problems with horses chewing wood, thankfully. Neither in the barn or in turnout.
A lady down the road did that for her pastures and it looks terrible. You can tell that they are landscape posts/rails and it doen’t look sturdy to me at all. I wouldn’t do it my self.
We used 4 x 4 pressure treated for posts and some corners, with T-Posts( capped) in between and woven livestock fencing. We’ve since found a source for used telephone poles that are wonderful as corner posts and a now and then post between the Tposts. we buried them about 5-6’ down and they’re goin’ nowhere! Our original turnout areas were done in cedar and that’s about 30 years ago. Some have fared better than others, but most seem still useable as we replace them. We didn’t reuse them, but they were in not too bad shape.
Nope, we don’t recommend them at all. Have seen way too many installs using them
with warped posts. They are not nearly as strong as 4-inch or better posts and round
fence posts are stronger than square fence posts of the same diameter–has something
to do with the growth rings.
I also do not recommend them. They tend to warp and aren’t very strong. I strongly believe in doing something right the first time and using these will result in needing to replace posts considerably sooner and spend more money than if you did it right in the first place. We have them here but did not put them in. They are breaking off at the ground and just weak. The nail-in type insulators do not stay in them as well either (kinda soft). For all the new fencing we are using 4"x6’ or 4"x8’ and are put in using a post driver. Corner posts are 6"x8’ with braces. Very strong and no need for concrete. They are round but it is not a problem nailing in insulators and they do lay flat on the surface.
Don’t do it!
Ours are rotting after about 6 years. Hubby regrets using them. Most recent fence is made from 6-8" 8ft fence posts. Lots more expensive, but will outlast many times over.
SD
I went the landscape tie route once too, and ended up replacing those posts shortly after due to rot.
I have to say though, I worked for parks one summer and was given the task of repairing an old split cedar fence. Out of about 2km of fencing we only replaced a few posts, and those were mostly ones that had been broken by falling trees. Records indicated the fence was built in the 1930’s when the park was a farm! The property was donated in the 50’s so there certainly wasnt any maintenance after that till we tackled it - the size of the trees growing around and through it are testament to that. It appeared the posts had the bottoms burnt before planting them, not sure if thats what kept them so strong? Too bad my horses have a taste for cedar, it’d only have about a 5 min lifespan round here 
We have used them very successfully with hot tape. I have some that have been in the ground for ten years and look just fine.
Mine are over ten years old as well (see earlier post). None have rotted or broken. Well, except the one I ran over with the tractor.
I did make sure that the ones I used were pressure treated just like lumber is and not surface treated. Maybe that is the diff. between ours and everyone here saying they are bad.
Landscape poles as fence posts
We put in a 3 acre pasture using landscape timbers (except for the corners and holding the gates) with the 2x4 no climb wire mesh Diamond fence. 15 yrs later the fence still looks great and the landscape timbers are holding up very well. I also use the landscape timbers for ground poles and for the jump course on an outside grass course and again 15 yrs later all is well. It must be the part of the country you live in. No complaints here.
I have 4 acres done in landscape timbers with generic electrobraid. Clay soil with few rocks, in front of pasture gets a bit wet. So far so good, the poles have been in 4 years with absolutely no issues.
No!! I second everyone else. The previous owner used them here for a beautiful white 3 board fence…I’ve seen the pictures from 10 years ago. When we bought the property 2 years ago most of the fence was no longer standing due to the posts rotting (both below and above ground). The part that was standing could be pushed over. The pressure treated boards of the fence are in bad need of a coat of paint, but are still strong and sturdy. We collected all of them and piled them up to make a new fence. The posts all went in the trash. The extra money for posts made to be used as fence posts is more than worth it.
I didn’t read through the other answers you got, so mine might be redundant.
But absolutely NO. Do not use them. I put them in (assured by the landscape material seller that they would last- -they were treated) and within 4 years they ALL rotted at ground level and had to be replaced.
There are degrees of ‘treated’ lumber-- and landscape poles have the lowest degree/concentration as they are really meant to stay above ground, not buried. Plus they are made of less hardy wood to begin with. I have a bunch of them still laying on a pallet-- covered by a tarp-- and even those are rotten through and through.
I wouldn’t even use these types of poles for the use they were intended. Nothing but rot!
