‘Leslie Roy’ is a fast-growing mesquite hybrid that offers several improvements over the two parent trees, including being thornless and producing very few seed pods. Here’s everything you need to know about planting and caring for this patented hybrid.
‘Leslie Roy’ mesquite (Prosopis x ‘Leslie Roy’) is a medium size shade tree that’s a cross between velvet mesquite (Prosopis velutina) and Chilean mesquite (Prosopis chilensis). It was developed by Tucson’s Civano Growers and provides a few significant benefits over either of the two parent trees.
Unlike most mesquites, this patented hybrid is thornless and has very few seed pods. (Some mesquites drop thousands of pods every summer.) It stays a manageable size for urban and suburban lots, typically reaching a size of 25′ by 25′. (Compare to Chilean mesquite, which can reach 50′ tall by 100′ wide!)
Its fern-like foliage casts dappled shade, a welcome feature in any desert garden. It grows up and out by several feet per year, which is important when you want some shade fast.
When in bloom, ‘Leslie Roy’ mesquite attracts bees and other insect pollinators. It always provides a haven for birds who use it for perching, nesting, and shelter.
Why I Like This Plant
- Attractive, fast-growing shade tree
- Low water, no fertilizer
- Few seed pods, no thorns
- Attracts wildlife
When I moved into my new construction home in the spring of 2022, there was literally nothing growing in my backyard. It was bleak, but I was excited to create a garden of my own design. I knew I wanted one large tree as the focal point. After much research, planning, and visiting nurseries, I decided on this tree.
It’s filled in faster than I expected and provides pleasant dappled shade. My husband and I refer to it as the “tree of life” since it’s always buzzing with birds. Here’s a picture of mine at 2 years old. (It’s about 8 feet tall and 12 feet wide at this point.)
Things to Watch Out For
‘Leslie Roy’ mesquite grows as a multi-trunk tree. It should not be trained into a single-trunk “lollipop” tree, if that’s what you’re looking for.
This tree is semi-deciduous, typically losing some of its leaves in the winter or in the spring just before the new leaves push out.
Don’t plant this tree if you are not willing to have it professionally pruned (by an arborist, not a guy with a chain saw.) If pruned incorrectly, it can grow water sprouts near pruning cuts anywhere within its crown. (I was dismayed that the few cuts I made encouraged these. And I thought I knew what I was doing!) 😟
Training this tree definitely takes skill and experience, so be prepared to hire professional help.
Optimal Growing Conditions
If you’re thinking of adding a ‘Leslie Roy’ mesquite to your garden, you need to find a suitable place that will keep your plant healthy and looking good… while minimizing maintenance for you.
Here are the key factors to keep in mind.
Temperature
Leslie Roy mesquite should be grown in USDA Hardiness Zones 7 – 11. It is tolerant of extreme heat and cold and can withstand temperatures down to 10℉.
Sun Exposure
Like all mesquites, it thrives in full sun and should get at least 6 hours of full sun per day.
Size and Growth Rate
This tree is a fast grower. When mature, you can expect it to be 25′ to 30’ high and wide.
Soil
‘Leslie Roy’ mesquite is not particular about soil and does well in any native desert soil provided it’s well-draining.
Other Location Considerations
‘Leslie Roy’ is a fairly garden friendly tree. Unlike other mesquites, it has no thorns and very few pods, which can make a real mess. However, it has fine leaves and stems which it loses throughout the year. These are largely inconspicuous on gravel or mulch, but you wouldn’t want them falling into a pool.
‘Leslie Roy’ Mesquite:
The Essentials
| Common Name | ‘Leslie Roy’ mesquite |
| Scientific Name | Prosopis x ‘Leslie Roy’ |
| Origin | Sonoran Desert/ South American hybrid |
| Plant Type | Semi-deciduous tree |
| USDA Zones | Zones 7 – 11 |
| Cold Hardiness | To 10℉ |
| Flower Color | Creamy white |
| Flower Season | Spring |
| Mature Size | 25’ high x 25’ wide |
| Growth Rate | Fast |
| Sun Tolerance | Full sun, part sun |
| Water Needs | Low |
| Pests & Diseases | None |
| Garden Friendly | No thorns |
| Wildlife | Attracts birds, bees |
How to Plant
The rule of thumb when planting any tree in the desert is to dig a hole three times as wide as the root ball but no deeper. Amending the soil is not recommended. Counterintuitively, backfilling with the same native soil you just dug up helps your plant develop a stronger root system.
When to Plant
The best time to plant a mesquite is in the fall. This gives your tree three seasons to grow roots and get established before the following summer.
The second best time is in spring, the earlier the better. This still gives your plant time to get established before the intense heat of June arrives.
How to Care for ‘Leslie Roy’ Mesquite
Whether you’ve recently planted a new ‘Leslie Roy’ mesquite or have an existing one in your yard, here’s how to take care of it to keep it healthy and looking its best.
How to Water New Plants
Once you’ve got your ‘Leslie Roy’ in the ground, watering is your most immediate concern.
Here is the recommended watering schedule for new trees planted in the spring or fall.
| Weeks 1 & 2 | Every 3 – 4 days |
| Weeks 3 & 4 | Every 6 – 7 days |
| Weeks 5 & 6 | Every 7 – 10 days |
| Weeks 7 & 8 | Every 10 – 14 days |
After week 8, gradually extend the time between waterings.
How to Water Established Plants
As your tree becomes established, there are two watering factors to consider.
- First is how often to water. This will vary with the seasons.
- Second is how much water to give your tree with each watering. This depends on its current size.
To determine the ideal watering schedule for any desert tree, you’ll find everything you need to know, including easy-to-use charts, at How to Water Desert Trees: How Often? How Much?
Once your tree is established it won’t need much water. My tree had been in the ground 2 years when my arborist recommended that I stop giving it supplemental water, unless there is extreme drought. Too much water promotes overly rapid growth, resulting in weak wood.
Should You Fertilize?
‘Leslie Roy’ mesquite does not need fertilizer.
Pruning: Professional Care Highly Recommended
Mesquites are multi-trunked trees that get big fast. Unless you have experience pruning this kind of desert tree, I strongly urge you to hire a professional to prune your tree. Hiring an arborist (not a so-called “landscaper”) to get your tree off to the right start is an excellent investment that will result in a beautiful tree that will grace your yard for decades to come.
Plant Lover Facts
This plant is a patented hybrid officially known as ‘Leslie Roy’ PP23360. Civano Growers developed this tree and named it after the patriarch of Civano Growers and Nursery’s Shipley family.
Mesquites were previously in the Proposis genus but were recently moved to the Neltuma genus. However, I’ve used the genus Prosopsis in this article for these reasons:
- It’s still the most commonly used name for this tree.
- It’s the name still being used by Civano Growers. (I’ll revise the name when they do!)
- It’s the name on the patent.
Have you grown this plant?
Was it a “hit” or a “miss” in your garden?
Please share your experience in the comments below!
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Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for 15 years.
Hello ! Just discovered your newletter during a Google search ! One of my trees died (way past its life expectancy) and when I read about the Leslie Roy Mesquite I thought I’d found the perfect replacement ! Unfortunately, I live up north in Kingman and I am unable to locate an arborist locally, so very reluctantly, I will take your advice and not plant one, even though it would otherwise be perfect. If you have a suggestion for an alternative with similar characteristics, please LMK. Thank you !
You might want to check out the Facebook group Ask an Arborist Arizona. The people in this group are very knowledgeable and maybe someone knows of an arborist in your area who could help you.