Arborvitae toxic to horses... need privacy screen ideas

Yesterday my farrier asked me for ideas on a privacy screen around a property he is buying. He said it’s about 2.5 acres. He wants to put something around the entire perimeter, leave a path, then fence. I don’t know if he is planning to have a horse at home, only that he’s establishing a shop where clients can haul in. He said he’ll have stalls where clients can drop off. At the moment that’s all I know.

My first thought was arborvitae. He said he didn’t want to just plant trees (such as fir). I told him I’d do some research on arborvitae varieties, etc., and in doing so found out it’s toxic to horses.

Okay… so now I need some other ideas. What have any of you used as privacy borders for your farms?

Did not know thuja was toxic to horses. Around here it’s considered to be deer candy.

My suggestions would be (depending on the USDA zone) cedars, junipers, privet, some species of viburnum. Or a mixed hedge of several of these. The first two are evergreen, (here privet is so-so, and the berries are toxic to dogs and humans). Viburnum has pretty flowers, berries and fall color depending on type chosen.

Good of you to do this research!

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What area of the country / USDA zone? That might inform suggestions for what will actually grow.

I second the ‘mixed hedge’ approach – different heights, different densities, depending on the season. Make it a wildlife habitat with some berry bushes, etc.

I’d also call the agricultural extension agent for your area… our tax dollars pay for them to know this kind of stuff.


An often overlooked good animal habitat for privacy screening is the Eastern Red Cedar.
Grows fairly fast, has berries that feed many birds and wildlife, is evergreen and provides winter habitat and nesting areas for many birds and is cheap when you buy seedlings.

Many county extension offices have a seedling plant sale periodically and you can buy them for pennies. Also when birds eat the seeds, they drop the actual seed and it starts new plants for free.
I have a couple naturally seeded by birds on my farm and wish I had many more.
For wildlife they can’t be beat.


Miscantheus x giganteus is a variety of miscanthus grass that grows 12-15 ft tall by its 2nd year and is not invasive. It will not spread beyond where you’ve planted it. This is not true of every miscanthus variety, most of the ornamental varieties of miscanthus that you see in landscaping centers can spread by seed. The specific variety I’m recommending is a sterile hybrid and it will not spread. I’ve planted 3500 acres of it, I know this to be true.

It’s quite attractive, too. In the winter it will go dormant and be yellow & dry, but stays upright so you still have that privacy screen. In the late winter / early spring, you can just bushhog it and the next season’s growth will jump right up. You don’t have to bushhog–new growth will just grow up/around the dry stuff–but I think it looks nicer.

Hardy up to Zone 5b, though in that zone it’s a bit vulnerable to a winter kill its first season if you have a very cold winter. Mulching would help that, but of course that adds cost. I wouldn’t rule out Zone 5a or even 4, if you’re willing to take the risk and if you get through its first winter you’re probably ok. Tolerates most soil conditions as long as it’s not too sandy/dry or constantly boggy.

ETA: not toxic and even though it’s a grass, grazing animals and deer don’t bother with it. The leaves are quite sturdy and a bit sharp edged, so they quickly decide it’s just not good grazing.

here’s what it looks like in winter and summer

It’s planted as a rhyzome so you have to dig a hole and cover. More time consuming to plant than just scattering seed, but way easier than trees/shrubs. If I were doing a 2.5ac perimeter, I’d rent a trencher and do it that way.

Here’s a possible supplier. Hope this helps!!

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Italian Buckthorn (Rhamnus alaternus). There are other Rhamnus varieties that may work as well; several varieties are native to the PNW. Do you have the gardenter’s scriptures available? (aka Sunset Western Garden Book)? May be some suggestions in there; its recommendations are based on west coast micro-climates.

My Italian Buckthorn is about 10 ft high now (5 yrs old); I water it about 4 times during our scorching summers. Lush and green; I prune it occasionally to thicken it. My SIL’s is in a much more mild climate and is about 15’ tall.

@EssexFells HOLY COW! I did not know there was a variety of miscanthus that grew like that.

For others who asked, I am in Willamette Valley of Oregon. So I can grow “almost” anything. I did float the idea of using a mixed hedge for birds, bees, etc., and may even suggest Douglas Spirea.

Yes, I do have the Sunset Western Garden Book, LOL. I will look into buckthorn varietals.

I kind of need to see the property in person, to gauge sunlight and other things that affect what will or won’t grow. I have no idea what the soil will be, the water table, any of that.

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Be sure to evaluate for fire resistance as well.


I’m in SE Ohio with the same grass @EssexFells is talking about. It’s gorgeous, impossible to see through, and does not spread.

Down side is where we have ours we can’t brush hog it so in the spring I go out with a weed whacked with a blade and cut it down. It also provides great nesting spots for mice in the center of the grass. Ours our near the pool so we often are fishing mice out of the pool.

He could plant Arborvitae and probably be okay. My horses think it is inedible and won’t touch it, but it makes a superb scratching post. My horses love to go under there and scratch their backs and rumps against the branches. They don’t even try to eat it. Sort of like pine trees. They don’t think those are edible either.


I don’t know. I planted some Green Giant Thujas as a winter wind screen 15 or so years ago. two of them succumbed to our hot dry summers but the other are 20+ feet tall. The horses never touched them until…I had some workers here when I was not here and I was running a tape fence between two trees. One of the guys had a bright idea that the lower limbs on the Thujas needed trimming back to the trunk. Then the horses got in there and started to gnaw the bark on those trees ( thujas). Before the lower limbs were gone they could not reach the trunks and left them alone.

I was pissed and put hot wire around the trees and the branches grew back enough that the horses couldn’t mutilate the Thujas. I have no idea why they developed a taste for the trunks. They even were observed gnawing on some leaves. The horses were fine and that game became not as fun for them and they moved on to other things and no longer eat them.

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Honestly, if it isn’t something lethal in one mouthful (Japanese Yew or Oleander for example); I’m not sure I would worry too much? I mean, presumably the horses will be tied and not free to eat the privacy fence while at the farrier’s?
I’d prefer to aim for something that creates a really solid, horse proof barrier over toxicity in this situation because I don’t see horses out there grazing, but I do see the potential for a loose horse in an new spot that needs to get turned back. I’d go for a mixed border, using a variety of plants with an aim at things that hit 10 ft, like to sucker and create dense growth, and grow fast. Willow family, some viburnums (not all!), arborvitae, rhododendron, holly, native ilex, grey or red dogwood, hawthorn, that sort.
Oregon grape (mahonia) is an option too
Osage orange (I just recalled a post on that!) Now you want a fence?! That is a fence!


Some of these suggestions are actually invasives. Please check on that before planting.


Please do not plant invasive species, like privet (shudder, I can’t believe it’s still legal to sell that nonsense) - these plants cause widespread damage. Google your state + “native plant society” for a good place to start.


I second this. Tell your farrier if he plants all native plants for a luxurious hedgerow, he be providing a natural place for many beautiful songbirds and wildlife.
Native plants not only provide nectar, berries,and seeds and nuts but also habitat for nests and
places to rear their young.
We need to bring back native hedgerows for farms.

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Don’t worry. I’m an experienced plant person and I am aware of a number of invasives, and will be doing full research before recommending anything.
I am considering natives that would work, such as Douglas Spirea. There is a natives nursery not far from me that I might consult with also.
He texted me a picture last night and said ‘what about this’, OMG I shuddered. It was just your standard laurel hedge. LOL. The gardener in me just wanted to roll on the floor and die!
I asked him if I could see the property before I make any more recommendations and he was most enthusiastic about that.
Whatever I recommend, I will be doing as much research as I possibly can before planting anything.
This will be a fun winter research project!!


OOOOH! I just came across this…