Palo Verde Tree Growing, Care Tips: No Water Tree? Edible Flowers and Seeds?

How To Identify Palo Verde Tree

The Palo Verde has several distinctive characteristics that make it relatively easy to identify.

You can check the characteristics below:

Palo Verde Tree Leaves

The leaves are usually pinnate, although they can occasionally be bipinnate, which sport many leaflets. These leaves are usually borne for a relatively short time after rain because much of the plant’s photosynthesis can be carried out by the tree’s trunk and branches.

Palo Verdes are deciduous.

Palo Verde Tree Flower

The flowers are symmetrical or nearly so, with five yellow or white petals.

They are edible.

Palo Verde Tree Seeds

The fruit is a green-brown pod, about 2-4 inches in length. It contains several seeds.

Palo Verde Tree Size

A Palo Verde Tree can reach a height of around 10-12 meters. The canopy is of roughly equal width.

Types of Palo Verde Tree

The Blue Palo Verde Tree (Parkinsonia florida) is the most common species. It is usually spotted near water sources.

(Image: Department of Horticulture¹⁸)

The foothills Palo Verde (parkinsonian microphylla) favors rocky slopes; they commonly have a more yellowish trunk. The Mexican Palo Verde (Parkinsonia aculeata) is native to Mexico but found also in the USA.

There are various other species as well, including the “Desert Museum” Palo Verde, named after the Arizona-Sonora Desert Museum.¹¹ It was named in the 1990s when staff members there began to notice thornless species that bloomed throughout the summer.

Palo Verde Tree Growth Rate

Blue Palo Verdes bloom first. They can grow up to 40 feet high over the course of about 30 years.

They may die long before reaching 100.

The foothills Palo Verdes are usually about 15 feet high but can get up to 40 feet. The leaves are about one-tenth of an inch long with about three to five pairs of leaves along the stem.

Their life span can be 100 years or more. The Mexican Palo Verde can grow up to 8 feet per year and reach up to 40 feet high.

They bloom through August. They have leaves that are about the same size as the foothills species that usually consist of 10 to 40 pairs along the stem, which can be up to a foot long.

The Mexican Palo Verde life span is around 30 years.²

Palo Verde Ecology

One of the Palo Verde’s major pollinators is Centris pallida (aka the digger, or pallid bee), a solitary bee. It obtains nectar and pollen from the Palo Verde to fill a brood pot that feeds its larvae when they hatch.

Palo Verdes themselves provide a desert canopy microhabitat – warmth in the winter and shade in the summer- for plants like saguaro cacti. Over the course of a Palo Verde’s life, it can be replaced by the cacti it reared, which will have a longer life span.

The Palo Verde is also a foraging ground and food source for numerous birds. Various species of mammals – from small rabbits and feral burros to bighorn sheep and mule deer – browse them.

During the Palo Verde’s flowering period, they attract numerous pollinators, including various species of beetle, fly, and bee.³

Companion Plants for Growing Palo Verde Tree

The best garden compliments to a Palo Verde would be other desert plants. The desert willow tree is an excellent tree choice.

For lower plants, the marigold, desert agave, yucca, and ocotillo will all go excellently. Different types of palm trees (Arizona) would also work.

For more examples, you can use this desert plants chart.

Growing Palo Verde Tree From a Seed

Fruiting times vary by tree species, but you can collect a pod from the ground under a tree after it has dropped. Then, open the seed pod with scissors and remove the seeds.

There are two ways you can prepare your seeds to give them a better likelihood of sprouting. One is to knick or sand a small hole in the outer shell.

The second is simply to soak the seeds for 24 hours to soften them.

Then place the seeds in small planters with soil including at least one-third sand or gravel to make sure it drains well. You want to keep them at around 70 degrees FH and the soil moist until sprouting, which should be about two months or less.

When to plant Palo Verde Trees for the best yield (where to grow them) is probably late summer, so the tree has time to spread its roots before the stressful winter.

Once the seed has sprouted, transfer it to your planting location. Remember Palo Verde Trees can be as large as 40-50 feet tall and with an equally large canopy.

The Palo Verde can grow in almost any well-draining soil, so you won’t really have to worry about fertilization or pH.

Water the surrounding soil until it is soaked to a depth of several inches. Continue to water fairly regularly – every couple of weeks in the summer, and once a month in the other seasons – until they have established themselves.

This may take up to two years.⁴

Growing a Palo Verde Tree From a Cutting

Unfortunately, growing Palo Verde Trees from cuttings aren’t possible. There’s nothing you can propagate, meaning you have to start from seed.

Growing a Palo Verde Tree From a Seedling

Palo Verdes are also rarely started from separate seedlings. It would be difficult to establish an existing seedling in a harsh dry climate.

Locating a Palo Verde Tree (Palo Verde Tree Growing Zone)

The most important planting tips for Palo Verde trees have to do with where to grow. In particular, spacing, sun, and soil.

Depending on the species, your tree could grow to a height and width of 30-40 feet.

The most important consideration is appropriate soil. Also, Palo Verdes don’t do well when planted in grass and will decline over time.

You probably will not want to plant them close to swimming pools due to flower litter in the spring. How far apart to plant Palo Verde Tree, will depend on the species, but plan on a distance of at least 25 feet.

If you plan on planting trees on property line, read this guide first!

How Long It Takes To Grow Palo Verde Tree (Planting Tips for Palo Verde Tree)

The growth of each tree depends on multiple factors, the most important of which will likely be its species.

Blue Palo Verdes can get up to 40 feet over the course of 30 years and can die before reaching 100 years old.

(Image: Chic Bee²⁰)

The foothills Palo Verde can reach less than half of that height but can live over a century. Mexican Palo Verdes can grow around 8 feet per year and reach up to 40 feet.

However, they live around only 30 years.² Here you can find further descriptions of different species.¹²

Watering Needs for Palo Verde Tree Plants

Since the Palo Verde is a desert tree, it doesn’t need much water to thrive. In fact, you’re probably more likely to overwater your tree rather than underwater it.

The exception would be for a very young tree. One watering option, if you want to give your young Palo Verde Tree extra attention, is to dig a shallow basin around it, at a diameter of about 2-3 feet from the trunk.

Deeply water the basin about once a week, and as it soaks into the ground, it will encourage the tree’s roots to stretch out and establish, making it even more drought-tolerant in the future. This can be continued after a couple of months after which time the basin should be refilled with soil.⁵

No-Water Tree

One of the best parts of Palo Verde tree growing is that once the tree is established, it generally does not require much if any additional water. For this reason, it is commonly called a ‘no-water’ tree.

Without supplemental water, however, Palo Verdes can be slower growing and tend to remain more shrub-like. As previously mentioned, the main concern is over, not under-watering.

If you suspect your soil is lacking in drainage, work some sand or pea gravel into it to a depth of about a foot.

Once the tree has been in the ground for at least 3 years,  you can follow these general guidelines and modify as needed: Water one to two times a month in spring/fall, two to three times a month in summer, and monthly in winter.

Palo Verde Care Tips

• Staking

A young Palo Verde may want to stake if it cannot evenly support its upper growth or if wind threatens to uproot it. In that case, consult this guide on staking.¹³

• Fertilization

In general Palo Verde Trees do not require fertilization. However, if you are going to use one, organic fertilizers are best!¹⁴

• Pruning

Palo Verde Trees benefit from pruning their low branches during warm weather while they’re established to raise the canopy and promote a more upright form. One mistake to avoid is called ‘lion tailing’ which is basically pruning up too high, leaving only the upper branches.

This deprives the tree of foliage needed to produce energy and increase strength. It also increases the amount of overhanging branches toward the top making the tree more likely to fall.

‘Desert Museum’ Palo Verde trees generally need pruning at least once a year. The best time is close before the monsoon season.

Remove any heavyweight or branches that are weakly attached.⁶

Common Pests of the Palo Verde Tree

Palo Verde trees are known for being extremely hardy. But there are some pests that put the tree’s health at risk.

• The Palo Verde Beetle

Several tree species have beetles that prey on them. The birch tree has the birch beetle, for example.

And the Palo Verde has the Palo Verde Beetle, aka the root borer or borer beetle. It’s a type of longhorn beetle native to the same area as the Palo Verde Tree.

They hatch from eggs into grubs, which are cream-colored to pale green, typically with a brown head. These feed on the roots of trees – in the wild the most commonly the Palo Verde Tree – which causes the branches to die back.

The larvae will live underground for up to three years. Huge specimens (up to 5 inches long) are sometimes uncovered by gardeners doing yard maintenance.

Here are some pictures of the Palo Verde Beetle and its larva form.¹⁵

Adult beetles usually emerge in late summer to mate. In this form, the Palo Verde Beetle is also one of the largest beetles found in North America, reaching up to 3 ½ inches in length.

They are black or brown in color and have long antennae and spines on the thorax. They have wings and can fly, though not particularly well.

Adults do not eat.

They live on energy reserves, mate, and die in about one month. They are not considered harmful to humans.⁷

• The Palo Verde Gall Mite

These mites are quite tiny, about .2mm long, so often you will notice their damage before the mites themselves. One symptom is when small, dense clusters of darker branches develop on the outer parts of the tree with the resulting structure resembling a broom or a bird’s nest.

The mites live inside this area, and while the condition is mostly cosmetic, it can weaken the tree’s health and appearance. Eventually, the infested branches could die if not treated.

Gall mites do not have wings, they can make their way to nearby trees with the help of the wind, birds, or bigger insects.

Natural Pest Control for Palo Verde Tree

Pests usually only thrive on weakened Palo Verde Trees. So as usual, an ounce of prevention is worth a pound of cure.

Both the Palo Verde Beetle and the gall mite can be deterred with simple regular pruning. In the case of an existing problem with gall mites, wait until early spring when they are dormant, then prune away all clusters of witches broom.

Alternative solutions include things like applying neem oil, which can be diluted and sprayed onto the affected area. In a worst-case scenario contact your local eco-friendly pest control service.

In reality, the palo verde is at relatively low risk of perishing by pests or of any pests it attracts causing a serious inconvenience to its surroundings, including you.

Can You Grow a Palo Verde Tree in a Pot?

The Palo Verde is a desert tree, so it does best in quick-draining sandy or gravel-rich soil. You can pot the Palo Verde in a commercial mixture designed for cacti and succulents, or make your own.

Just combine two parts of standard potting soil or humus, one part perlite, and one part of small-size gravel or coarse sand. Don’t place a saucer under the pot.

Again, rapid drainage is best. It’s also best to choose an unglazed ceramic vessel which will afford quicker evaporation.

Regarding size, look for a pot about 6 inches wider in diameter than the tree’s root ball, to allow for growth.⁴

What Will a Palo Verde Bring to My Garden/Yard?

As a native tree, the Palo Verde will provide food and homes for our wildlife. Hummingbirds love to nest in the tree and raise their young, as well as many other species of birds including mourning doves and white wing doves.

The seed pods are devoured by small animals. Rabbits will eat the fallen litter and quail will roost in Palo Verdes during the night.

Plus, both the wildlife and you will enjoy their shade in the summer!¹⁰

What Are Some Fun Facts About the Palo Verde Tree? (Palo Verde Tree Facts)

Palo Verdes can live over a century.

Their pollen causes little to no allergy symptoms in most people.

(Image: ksblack99¹⁹)

They can also nurse cactus growth beneath them.

What Is a Thornless Palo Verde?

Usually, Palo Verdes have rather large and imposing thorns protruding from the trunk and branches, however, some species lack them, and as a result, are usually more popular for domestic planting.

The desert museum Palo Verde Tree is probably the favored species.

Its trunk is a remarkably deep green; it produces large flowers, its thornless, and a quick grower.

How To Identify Palo Verde Tree (How To Stop Palo Verde Tree Disease)

Like most all trees, the Palo Verde is susceptible to some pests. The most common are listed below:

• Root Rot

The most common Palo Verde fungal disease is Phymatotrichopsis Omnivora – also known as root rot.⁸ This fungus infects the roots of mature plants and causes deterioration in health and eventually death.

It occurs in the soil and has no aerial or soil-borne spores that spread it. Its strands grow and colonize nearby tree roots, using them as an energy source.

They then grow short distances through the soil to infect other healthy roots, and can even produce survival structures called sclerotia. This ability to grow between hosts explains how the fungus kills patterns of adjacent plants in gardens.

An entire group of plants may succumb together. The process is slow.

The fungus may only kill a plant or cause obvious signs of decay years after initial infection. Unfortunately, there is no removal method for P omnivora.

However, if you keep your tree healthy it can survive for years even after infection. The best prevention against the fungus is simply making sure the soil in which you plant your Palo Verde is well-draining.

Learn more in-depth about P Omnivora from an NIH analysis.¹⁶

Culinary Applications

The Palo Verde Tree was used in various ways by the indigenous Quechan, Mojave, and Pima peoples. They carved ladles from their wood and used the beans as their food source.

Often the beans were taken when soft and immature and cooked whole. They also ground the ripe seeds into flour and ate them as atole or gruel.

The Palo Verde’s flowers are edible fresh or cooked and have a sweet flavor.¹

Edible Seeds

Immature Palo Verde seeds are edible raw, but they can also be prepared in a variety of ways. You can blanch and blend them into a paste, freeze, brine, or ferment them.

Mature Palo Verde seeds are best cooked and can then be toasted and ground into flour.

This can then be used in a variety of ways. For example, add water to the flour from the toasted seed to make Pinole, a type of porridge.

Fresh green seeds should first be blanched, either in the pod or after shelling. Place them in boiling water for a couple of minutes.

Then remove and shock in cold water.

Drain and dry them thoroughly. Then store in an airtight container.

The seeds, if dried, are best eaten sprouted- either raw or then parched/roasted. To sprout Palo Verde seeds, soak them and then rinse once daily until the seed splits open and the sprout emerges.

Then remove the seed coat to isolate the sprout. Then rinse. Cook if desired.⁹

Edible Flowers

The Palo Verdes flowers are a fantastic raw treat.

(Image: Alan Levine¹⁷)

While less substantial than the seeds, they can add color as a garnish and have a pleasant sweetness.

Nutrition

Palo Verde seeds are 41% protein. Like most seeds, they offer an array of healthy vitamins and minerals.

In any case, make sure you are eating from a tree that has not been exposed to toxins or carcinogens like those found in pesticides or synthetic lawn treatment products.

Nutritious fruits are just another benefit of growing a Palo Verde Tree!

Frequently Asked Questions About Palo Verde Tree