SW (low desert) adapted trees safe for horses

[cardinale]

There are extensive lists of plants toxic to horses that I am checking before buying trees to plant in a small pasture area, but the preponderance of species listed are commonly used in the Eastern or Midwestern U.S.

I need trees that withstand extreme heat, i.e. desert adapted. Information seems to be more difficult to find for these. Has anyone from the Phoenix, Tucson, SE California, or other hot weather areas seen these trees planted safely around horses:
Willow Acacia Acacia salicinia
‘Drake’ Elm Ulmus parvifolia ‘Drake’ I’m assuming this one is O.K. because I’ve never heard of any problems with elms in horse pasture.

They are the best candidates I’ve identified so far because they are available and throw fairly good shade. There are other trees that do well here but are toxic to horses–live oaks, pistachios. Others I’m ruling out because they have invasive root systems are figs and Sissoo. Some others–Palo Verde and similar pea family trees–have a lacy branch system that doesn’t make much shade.

Any other suggestions are most welcome.

Thanks

[Willesdon]

What species grow naturally, where you are located? They will be adapted to the climate. Then find the ones that do the job you require. Sometimes a clump of trees is better than a single or a line.

[Where_sMyWhite]

What state and county are you in?

I would recommend contacting your County Extension office and talk to their ag Agent.

Most trees native to the Sonoran Desert have small leaves. Helps them not loose too much water through transpiration. So, yes, shade but not a traditional “shade” tree.

A tree you might consider (depending on location) would also be the Joan Lionetti Live Oak (Quercus fusiformis ‘Joan Lionetti’ PPAF) from Civano Nursery in Tucson.

Named for the founder of Trees for Tucson, the Joan Lionetti live oak is the first and only oak cultivar that was selected and bred specifically for our unique growing conditions in the arid Southwest

Having said this, any young tree you plant in the desert SW will need water until it gets established. This summer in Maricopa County plants that didn’t get some sort of irrigation did not do well because we didn’t have much of a monsoon.

Don’t know where you researched your two choices… don’t know that the Weeping acacia would be my first choice for a pasture tree based on its structure.

http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/acaciasalicina.html

From a structure perspective the Chinese Elm might work better but you’ll need to supplement water it as it isn’t native to the desert southwest.

http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/ulmusparvifolia.html

FWIW, I am Maricopa Master Gardener

[Amym600]

The willow takes forever to grow, and if you look in the desert they tend to low branch and make terrible shade trees. They also shed like crazy. Add to that they flower heavily and attract bees. I would hard pass on those. I have mesquite trees around my arena and turnouts. But far enough away I can keep them trimmed and horses have no access or they eat the beans, and ruin the trees.

[Amym600]

@Where'sMyWhite

What state and county are you in?

I would recommend contacting your County Extension office and talk to their ag Agent.

Most trees native to the Sonoran Desert have small leaves. Helps them not loose too much water through transpiration. So, yes, shade but not a traditional “shade” tree.

A tree you might consider (depending on location) would also be the Joan Lionetti Live Oak (Quercus fusiformis ‘Joan Lionetti’ PPAF) from Civano Nursery in Tucson.

Having said this, any young tree you plant in the desert SW will need water until it gets established. This summer in Maricopa County plants that didn’t get some sort of irrigation did not do well because we didn’t have much of a monsoon.

Don’t know where you researched your two choices… don’t know that the Weeping acacia would be my first choice for a pasture tree based on its structure.

http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/acaciasalicina.html

From a structure perspective the Chinese Elm might work better but you’ll need to supplement water it as it isn’t native to the desert southwest.

http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/ulmusparvifolia.html

FWIW, I am Maricopa Master Gardener

OHH! I am going to pick your brain now! Master Gardener here is hard to find. I had an oak tree in my backyard before my horse place. The damn acorns were horrible. Dogs ate them and threw them up and they were a mess, but I think it was a southern Oak.

[Brown_Derby]

Possibly fruitless mulberry and hackberry; they love the heat. There is a hackberry that is native to the desert, though it does not grow as tall as the Chinese and Australian varieties…

[Where_sMyWhite]

@Amym600

OHH! I am going to pick your brain now! Master Gardener here is hard to find. I had an oak tree in my backyard before my horse place. The damn acorns were horrible. Dogs ate them and threw them up and they were a mess, but I think it was a southern Oak.

What state and county? I can really only answer questions about gardening in the low desert in Maricopa County (Phoenix). Tucson has a fairly different climate so what might work in Maricopa County may not work as well in Tucson (Pima County).

If you are in Tucson, the University of Arizona has a nice arboretum.

http://arboretum.arizona.edu

If you are in the Phoenix area, Arizona State University also has a number of Plant Collections throughout the campus.

https://cfo.asu.edu/arboretum-plantcollections

These plant collections would give you an opportunity to see the mature trees to decide if you like it or not.

[cardinale]

Thank you for the informative replies. I’m closer to Phoenix than Tucson.Trees will be irrigated (otherwise, as people have pointed out, no trees :lol:).

My understanding is that oaks are toxic to horses? Maybe only some oaks? I love the Southern live oaks (Quercus virginiana) which are widely planted in Phoenix but are any oaks safe around horses? Trees will be fenced in around the trunk but some leaves will fall–would that be a problem if they end up in the(limited) grassy areas and horses eat them? This live oak is in a different section of the oak family than e.g. red oaks which are apparently the most toxic so maybe the live oak would be OK? I just however called the nursery in Tucson that sells the Joan Lionetti cultivar and was told it produces a lot of acorns but that you can spray in the spring to prevent fruiting.

The willow acacia is different from the desert willow (yeah, it’s confusing)–Amym600 you are right the desert willow isn’t suitable, but the willow acacia is quite lovely. If it’s pruned at the top it can have a nice shape instead of getting spindly.

Mulberrys are a good suggestion–they do grow vigorously around here and provide shade–but I’m concerned that they would get too big for the available space. Hackberry is a good idea but I’m hoping for something that grows pretty quickly, which I’m not sure they do.

[Where_sMyWhite]

OP, did you ask Civano about the toxicity of the Joan Lionetti and what parts of the tree are toxic?

I am focused on urban horticulture and not ag so I am not that familiar with the toxicity of trees. Your county (Pima? Pinal?) ag agent could help with that.

I wouldn’t recommend desert willow as a shade tree although I love my desert willow in my back yard

The acacias can do well here originating in Australia. I’d be worried the ‘drape’ nature may not be suitable once the tree gets established and matures.

If you don’t like the shape of the willow acacia, please don’t prune at the top, select a tree that is what you’re looking for.

Whatever tree you choose, make sure it is suitable to withstand not only our summer heat but our alkaline soil. Some plants just don’t do well in our soils.

We learn, right plant, right place

[js]

@Brown Derby

Possibly fruitless mulberry and hackberry; they love the heat. There is a hackberry that is native to the desert, though it does not grow as tall as the Chinese and Australian varieties…

Check with your county extension office, in ABQ NM the mulberry is illegal to plant due to its very high pollen content. We have one in our backyard (planted many years ago), it is huge! It does provide wonderful shade but the branches are low and there are a lot of leaves to clean up in the fall.

[walkinthewalk]

I lived in SoCal five years and there were at least half dozen mature Eucalyptus trees right in the horse area, when I bought the property.

The problem is you HAVE to fence the trees off from the horses, even after they are well established, as the horses will eat the bark and kill the trees.

[poltroon]

I would talk to your vet about the oak trees.

The acorns are toxic… but different species have different toxicity, and also IME it’s typical for them to be in horse pastures without a problem, IF the horses have plenty of better stuff to eat. Your vet will know the difference, in your area between the plants that are real problems for toxicity and the plants that are on the list but not really a practical issue. Your extension agent is a good source also. I’d talk to both.

I would plant the trees outside the fence if possible, especially on the western side. If you have the space they’ll give afternoon shade but leaves and acorns will fall outside the fence. In a small pasture trying to keep trees inside happy is already a challenge.

[Where_sMyWhite]

@walkinthewalk

I lived in SoCal five years and there were at least half dozen mature Eucalyptus trees right in the horse area, when I bought the property.

FWIW, So Cal is not the low desert In general eucalyptus can do well but it will depend on the variety as our soil is often more alkaline, we are hotter and less humid than So Cal.

For me, consult your local County Extension ag agent (you have one and both Pima and Pinal (don’t know where you are)) should be able to give you good recommendations for your location.