Tag Archive for: Palo Brea

A Colorful Yellow April Display: Palo Verde Trees

April in the desert garden is, in my humble opinion, the most beautiful time of year for summer blooms.  Winter and spring-flowering plants (Damianita, Penstemon, and ‘Valentine’ Emu Bush) are just beginning to fade and summer blooms are beginning to appear (Coral Fountain, Lantana, and Yellow Bells).   

Clearly the most colorful event in April is the flowering of palo verde trees.  

Did you know that each species of palo verde has a different shade of yellow?  

It’s true. The differences may not be obvious unless you see them next to each other. I’ll make it easier for you and show you some examples below.

  • Blue Palo Verde (Parkinsonia florida)
  • Foothills (Littleaf) Palo Verde (Parkinsonia microphylla)
  • ‘Desert Museum’ Palo Verde (Parkinsonia hybrid ‘Desert Museum’)
  • Palo Brea (Parkinsonia praecox)
Blue Palo Verde (Parkinsonia florida)

Blue Palo Verde (Parkinsonia florida)

Foothills (Littleaf) Palo Verde (Parkinsonia microphylla)

Foothills (Littleaf) Palo Verde (Parkinsonia microphylla)

'Desert Museum' Palo Verde (Parkinsonia hybrid 'Desert Museum')

‘Desert Museum’ Palo Verde (Parkinsonia hybrid ‘Desert Museum’)

Palo Brea (Parkinsonia praecox)

Palo Brea (Parkinsonia praecox)

The arrival of these yellow flowers is met with delight by many and to the dismay of others. Those that like clean, pristine landscapes, without a stray leaf or fallen flower, don’t like the flowers that they leave behind.  

As for me, I like things mostly natural and the golden carpet that my ‘Desert Museum’ palo verde trees leave behind, is a welcome sight.  

A Contemporary Garden with Summer Blooms

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summer blooms are beginning to appear

I like the contemporary entry to the above front garden flanked by desert spoon and the columnar cardon cacti (no, they aren’t saguaros) surrounded by golden barrels, it was the majestic ‘Desert Museum’ palo verde trees that caught my eye.

summer blooms are beginning to appear

Summer Blooms

Exploring the Garden’s Design

The plant palette is limited. This works well with contemporary design. The trees are pruned a bit too high. I like the flowers from the palo verde trees along the street decorating the grass and sidewalk.

summer blooms are beginning to appear

My personal style is more informal. I do appreciate contemporary design and really like this pathway. I believe a better species of agave that can handle full, reflected heat without growing too large would have been better – maybe Twin-Flower Agave (Agave geminiflora) or Artichoke Agave (Agave parrying var. truncata)?  

I’m in love with the flowers. Aren’t they fabulous?

Victoria agave

My favorite picture is one of the entryways. The ground is a solid carpet of golden yellow flowers. This contrasts beautifully with the gray-blue walls and red door.  

How about you?  Do you like the way flowers look on the ground?  Or do you feel the overwhelming impulse to blow them away?  

I recently shared some examples of ‘butchered’ trees and asked you to try to identify what each tree was. You can take the quiz here, if you like before seeing the answers, below.

As promised, here the photos of badly pruned trees and what they should look like:

Badly Pruned Trees

Badly Pruned Trees

Desert Fern (Lysiloma watsonii)

Photo: #1 – Desert Fern (Lysiloma watsonii)

Badly Pruned Trees and What They Should Look Like
Shoestring Acacia (Acacia stenophylla)

Photo: #2 Shoestring Acacia (Acacia stenophylla)

Badly Pruned Trees
Chilean Mesquite (Prosopis chilensis)

Photo: #3 Chilean Mesquite (Prosopis chilensis)

Badly Pruned Trees
Palo Brea (Parkinsonia praecox)

Photo: #4 Palo Brea (Parkinsonia praecox)

‘Topping’ of trees is not only unsightly, it is also unhealthy – leaving trees susceptible to biological and environmental stresses and actually making them grow faster and use more water.

For more information on why ‘topping’ is bad for trees, click here.

Earlier this week, I was stopped at an intersection when I noticed the sad plants on the corner.

sad plants

I apologize for the poor-quality photo, but I only had a few seconds to take a picture with my phone through the window.

What was so sad about these plants was that they were mere shadows of themselves.

Many people would be hard pressed to recognize the over-pruned specimens above to what they look like when allowed to grow into their more natural shapes.

Here are photos of the same type of tree, taller shrub and cupcake shape shrub growing in happier  circumstances…

Palo Brea tree (Parkinsonia praecox)

The small mushroom-topped tree is actually a Palo Brea tree (Parkinsonia praecox), which has a beautiful shape.  The trunk is beautiful as it twists upward.

Unfortunately, the flowering shrubs underneath it have fallen victim to over-pruning.

Yellow (Mexican) Bird-of-Paradise (Caesalpinia mexicana).

The taller shrub from the ‘sad’ plant photo is a Yellow (Mexican) Bird-of-Paradise (Caesalpinia mexicana).

It can be grown as a small tree or tall shrub.    

over-pruned

Yellow flowers appear off and on throughout the year.  However, I doubt that the over-pruned Yellow Bird-of-Paradise is ever able to produce a single flower before it is pruned off.

over-pruned

Can you believe that the cupcake-shaped shrub in the first photo is actually the same kind as this gorgeous flowering shrub?

Perhaps more then any other type of desert shrub, those that belong to the family Leucophyllum (often referred to as Texas Ranger or Sage) are pruned into balls, squares, cupcakes and even disks.  

over-pruned

Unfortunately, due to a badly designed landscape, the lower shrubs don’t have enough room to grow. A single tree would have plenty of room to be able to grow, but not two.

A better plan would have been for there to be a single Palo Brea tree with 3 Texas Sage shrubs along the wall.  The groundcover, Bush Morning Glory (Convolvulus cneorum) works okay in this area.

**You know what is interesting about this small piece of landscape and countless others?  It would cost so much less if people would allow enough room for plants to grow to their full size, not to mention much more attractive.

There would be FEWER PLANTS to purchase, LESS WATER needed and far LESS MAINTENANCE required.

It makes you think about why people over-plant and over-prune, doesn’t it?

For more information on how to properly prune shrubs, check out my previous post, “The Good, The Bad and The Ugly”.

If you would like to see more badly pruned trees along with a link to how to properly prune trees, check out “Scary Pruning Practices and the Unfortunate Results.”

This is my favorite time of year in the garden.  You may be saying, of course it is….it is spring after all.  Isn’t that everybody’s favorite time?  Well, there is another reason.  This time of year I cannot go outside without coming back inside with a yellow flower or two in my hair.

yellow flower

Desert Museum Palo Verde (Parkinsonia hybrid ‘Desert Museum’)

All three of my Palo Verde trees are blooming.  Each one is covered in yellow blossoms.  Actually some of the branches are hanging quite low due to the weight of the flowers.  My Palo Verde tree above, is about 4 years old and will eventually grow to be about 30 ft. tall and wide.

yellow flower

 ‘Desert Museum’ Palo Verde flowers

Palo Verde trees are the iconic trees of the desert southwest.  The word “Palo Verde” is Spanish for “Green Stick”, which aptly describes their green trunks.

In times of extreme drought, they drop their leaves to avoid losing excess moisture and they will continue to photosynthesize through their green trunks.  What a great survival mechanism, don’t you think?

yellow flower

There are quite a few different types of Palo Verde trees.  My favorite is a hybrid that was found growing in the Tucson desert near the Sonoran Desert Musuem.  Appropriately, it is called ‘Desert Museum’ Palo Verde.  

It grow very quickly, is thornless, produces yellow flowers somewhat larger then their cousins and is quite low-maintenance.

Blue Palo Verde

Blue Palo Verde (Parkinsonia floridium)

Blue Palo Verde trees are also quite beautiful and an asset in the landscape.  Their bark has more of a gray-green color and is a slower growing Palo Verde.

Palo Verde trees flower in the spring and mine sometimes flower a little in the fall, although that is not always dependable.

Palo Brea

 Palo Brea (Parkinsona praecox)

Another type of Palo Verde is the Palo Brea tree.  Their trunk is bluish green in color.  They do have thorns and must be pruned often to keep their branches from growing downwards.  But, they are absolutely lovely in the landscape.

Foothills Palo Verde

Foothills Palo Verde (Parkinsonia microphylla)

Last, but not least, are the Foothills Palo Verde, which grow very slowly, but have beautiful branch architecture.  This is the type of Palo Verde that you will find growing out in the desert most often. 

Yellow flower

Yellow flower

Lately, every time I come back inside from the garden, I find a flower or two that has fallen into my hair. 

Did I mention that I love this time of year?

Sometimes when I am driving around, I see a poorly pruned tree or shrub, and I just cringe.  It never ceases to amaze me the crazy ways that people take care of their plants.  Whenever I see plants like this, I whip out my camera and quickly take a photo and then drive away before the homeowner asks what I am doing.

poorly pruned tree

 Butchered Palo Brea Tree

I mean if they catch me taking a photo, I can’t very well tell them, “I am taking pictures of the horrible way you prune your trees ?” Can I?  Well, I probably could and should, but I am too chicken to confront people that way.  I have no problem confronting people about their horrible pruning if they have asked me over to do a consult on their landscaping.  I just like an invitation first before I tell people what they are doing wrong 😉

poorly pruned tree

 ‘Topped’ Willow Acacia

poorly pruned tree

 Willow Acacia as it should look like.

Although, the primary purpose of this post is to entertain with photos of truly awful pruning disasters.  I just have to step up on my “high horse” for just a minute regarding one type of pruning that is widespread.  So please bear with me…

One of the most harmful types of pruning in regards to trees is called ‘topping’ the tree.  It removes a lot of the top growth.  This is usually done to shorten the tree and to preserve a view.  The topping is NOT good for the tree and accelerates more top growth.  The new branches are weakly attached and are much more liable to break, which can cause damage to what is underneath.  Also, topping trees greatly stress the tree which can make them susceptible to insect and certain environmental factors.  You can read more about topping trees here Tree Care.

poorly pruned tree

 Chilean Mesquite with a ‘kink’ in its trunk.

poorly pruned tree

  ‘Poodle’ Olive Tree

 Okay, the vast majority of trees should not be prune into round shapes.

Palo Brea tree pruned into a 'ball

 Palo Brea tree pruned into a ‘ball.’

Palo Brea tree as it should look

 Palo Brea tree as it should look.

Blue Palo Verde tree

 A Blue Palo Verde tree that lost its head.

A few years ago we suffered a severe micro-burst during the summertime at the community where I was working.   The tree above snapped off in the high winds at a weak point in the trunk, which was weak due to improper pruning that was done a long time before the storm.

Orange tree

 This is an Orange tree that has been pruned correctly.

The Citrus tree, above, has been pruned the right way, but I just had to include it in this post because it is so humorous.  Look closely (you can click on the photo to enlarge)…. the homeowner tied CDs to the tree to scare off the birds from eating the fruit.

Many people prune their Citrus trees up so that they look more like a ‘typical’ tree.  But what many people don’t know is that the lower branches produce the most fruit, the sweetest fruit and protects the trunk from sunburn.

Now for some truly awful examples of shrubs….remember the “cupcakes” from a previous post?

Cordia

 Little Leaf Cordia pruned into a ‘ball.’

In an earlier post, we covered the epidemic of pruning shrubs into the shapes of ‘cupcakes.’  Well, there is another epidemic in where people prune their shrubs into the shape of a ‘ball.’  We call this type of pruning, “Poodle-Pruning” because the shrubs resemble the ball shapes that poodles have when groomed.  Either way, ‘cupcakes’ or ‘poodle,’ neither are good for your shrubs and take away from their beauty.

Feathery Cassia shrubs

 Feathery Cassia shrubs with large areas of dead growth.

One of the results of repeated shearing of your shrubs into specific shapes (cupcakes or balls), results in areas of dead growth.  This is because sunlight cannot penetrate inside the shrub and it is constantly trying to replace the growth that is cut off constantly.  There is a cure, which I will cover in a spring time post, which is when corrective pruning should be done.

Thunder Cloud Sage

 Thunder Cloud Sage, unpruned

Now I don’t recommend going to the other extreme, above, and not pruning.  Just do it correctly.  So, if you have any ‘cupcakes’ or ‘poodles’ in your landscape, do not panic!  I will cover the correct ways to prune many shrubs in the spring, which is the time that it should be done.

So, take care to prune properly, because you never know when I will come driving by with my camera….

Large blooming palo verde an Iconic tree

  Iconic tree, Blue Palo Verde (Parkinsonia florida)

When people think of the Sonoran desert, hillsides studded with saguaro cactus and cholla often come to mind.   But interspersed between the cactus, you will find the palo verde, an iconic tree with their beautiful green trunks and branches.

An Iconic Desert Tree; The Palo Verde

The word “Palo Verde” means “green stick” in Spanish, referring to their green trunk, which is a survival mechanism in response to drought.  

Palo verde trees are “drought deciduous,” which means that they will drop their leaves in response to a drought situation.  Their green trunks and branches can carry on photosynthesis, even in the absence of leaves. 

'Desert Museum' Palo Verde planted in groups along a walkway

 ‘Desert Museum’ Palo Verde (Parkinsonia hybrid ‘Desert Museum’)

Palo Verde Trees Are Nurse Plants to Saguaro Cacti

Palo verde trees act as a “nurse plant” to young saguaro cacti by protecting them from the cold in the winter and from the intense sun in the summer.  Beautiful, yellow flowers are the product in the spring.    

Desert Museum Palo Verde Flower

 Desert Museum’ Flower

There Are Several Species of Palo Verde

There are three species of palo verde that are native to the desert Southwest; blue palo verde (Parkinsonia florida), formerly (Cercidium floridum), foothill palo verde (Parkinsonia microphylla), formerly (Cercidium microphyllum) and ‘desert museum’ palo verde (Parkinsonia x ‘Desert Museum’).

Grab my FREE guide for Fuss-Free Plants that thrive in a hot, dry climate!

Another species of palo verde that is prevalent in the landscape are called palo brea (Parkinsonia praecox), formerly (Cercidium praecox).  They have a dusty green trunk and branches that twist and turn.  Their cold hardiness range is around 15 to 20 degrees F.

Palo verde Iconic tree

 Iconic tree, Palo Brea

Palo Verde Landscape Uses

Palo verde trees serve as beautiful specimen trees where their green trunks, branch structure, and flowers serve as an attractive focal point in the landscape.  They are drought tolerant, once established and provide lovely filtered shade year-round.  

When deciding where to place your tree, be sure to take into account that they need a lot of room to grow, mature sizes are listed below.  

Palo Verdes don’t do well when planted in grass and will decline over time.  Locate away from swimming pools due to flower litter in the spring.

Because of their more massive thorns and branching tendency to point downwards, palo brea trees aren’t recommended in areas close to foot traffic.  

Mature Sizes:

  • Blue Palo Verde – 30 ft x 30 ft
  • ‘Desert Museum’ Palo Verde – 30 ft high x 40 ft wide
  • Palo Brea – 30 ft x 25 ft
  • Foothills Palo Verde – 20 ft x 20 ft

As with many desert trees, Palo Verde trees have thorns, except for the ‘Desert Museum’ Palo Verde.  

Palo verde in bloom Iconic tree

 Foothills Palo Verde

Basic Palo Verde Maintenance

Pruning for Canopy Elevation and Structural Integrity:

Pruning Palo Verde trees in your desert Southwest garden is a crucial aspect of maintaining their health, aesthetics, and structural integrity. One of the primary objectives of pruning is to elevate the canopy, ensuring it remains well-balanced and visually appealing. This practice involves selectively trimming the lower branches to create a more elevated and open canopy. By doing so, you allow for better air circulation and light penetration, which can promote overall tree health and reduce the risk of disease.

Steering Clear of Hedging and Topping:

While pruning is essential, it’s equally vital to understand what not to do. Avoid two harmful practices: hedging and topping.

  1. Hedging: Hedging involves indiscriminate shearing or cutting of branches to create a uniform, artificial shape. This practice is highly discouraged for Palo Verde trees, as it not only compromises the tree’s natural beauty but also disrupts its growth patterns. Hedging can lead to dense, bushy growth with weaker, more susceptible branches.
  2. Topping: Topping is the severe cutting of the uppermost branches, often leaving stubs or bare trunks. This practice is detrimental to the tree’s health and stability. When Palo Verde trees are topped, they respond with a vigorous burst of new growth that tends to be weak and prone to breakage. Topped trees are also more susceptible to pests and diseases.

The Proper Tree Pruning Approach:

Instead, adopt a thoughtful and strategic approach to pruning your Palo Verde trees. Start by identifying dead, diseased, or damaged branches, and promptly remove them. This eliminates potential entry points for pests and diseases, promoting tree health.

Next, focus on elevating the canopy by selectively pruning lower branches. When selecting branches for removal, prioritize those with narrow crotches or those that cross and rub against each other, as these can weaken the overall structure.

Consider hiring a certified arborist or a professional tree service to ensure that your Palo Verde trees receive the care they deserve. These experts have the knowledge and experience to prune your trees correctly, preserving their natural form and promoting robust, healthy growth.

By following proper pruning practices and avoiding hedging and topping, you can help your Palo Verde trees thrive in your desert Southwest garden. A well-maintained Palo Verde tree not only adds to the beauty of your landscape but also provides valuable shade and habitat for local wildlife while remaining resilient in the harsh desert environment.

Palo Verde is My Favorite Tree

As a landscape manager, horticulturist and arborist, I have grown and maintained all of the palo verde species mentioned, and I truly enjoy them all.  However, at home, I have 4 ‘Desert Museum’ trees. 

In comparison to the other species, their trunks are a deeper green; they produce larger flowers, are thornless and grow very quickly in the desert.  Also, they require little, if any, tree staking when planted. Simple amazing!