Cashew Tree Guide by a Tree Expert: How to Grow, Uses, Nuts (Warning)

Image Credit: Judgefloro¹⁸

In regards to this particular species of trees, a cashew tree guide by a tree expert may well be required to find out crucial information before you go out to purchase one.

Unlike many other fruit-bearing trees, a cashew tree must be planted correctly in the right habitat to ensure a successful harvest.⁷

Advice from an expert will help to avoid the pitfalls when planting and the dangers when harvesting. What are they?

Cashew Tree Overview and Warning

Cashew trees either grow from a seed or from a grafted tree.

Growing one from a seed involves planting 3 or 4 fresh seeds in a 5 cm hole in a plastic bag or a pot that contains sterilized soil, not forgetting that the stalk ends need to point upwards.

Sterilized soil is recommended to provide a purified environment devoid of harmful organisms so that the seeds have a better chance of growing stronger and healthier.

If more than one tree is to be grown, leaving 30-30 cm between the seeds when sowing them is advisable, allowing room for the roots to extend outwards unhindered at this stage.

After watering regularly for 10 -12 days, the seeds will have germinated and be ready for transplanting, but during this stage, weed out the weaklings, those seeds that are not growing well, and leave the strongest to thrive.

Before transplanting, prepare the ground by digging 10-15 cm deep holes about 30 feet apart, then gently bury the seeds. This process would be the same as planting a grafted tree, including watering weekly until the tree has matured.

What Is the Lifespan of Cashew Tree?

So, when a cashew tree reaches the ripe old age of 20, is it ready for the wood chipper?

Not at all.

Free from pests and disease, a tree can continue to live a further 5 years, with some surviving up to 40 years in total if properly tended to and if in an optimal growing environment.

How Many Cashew Trees Per Acre?

With proper spacing using modern techniques, it is possible to plant up to 400 trees on an acre of land.

This is achievable by reducing the distance when planting the grafted trees or seeds, and selecting a variety that can grow comfortably closer to its neighbor.

This denser method of planting increases the number of trees significantly from the 100-tree limit that was previously possible. Being able to plant more is a major boost for farmers, affording them greater yields, and greater profits.

Cashew Tree Fruit

This period of growing to maturity and bearing fruit differs greatly between these two methods.

From a seedling, it takes three years before fruits can be harvested. With a grafted tree, that time is reduced significantly to 18 months.

(Image: Sarangib.¹¹)

During this adolescent phase, the root system develops laterally as the tree grows, establishing a strong base where water can be absorbed easily. The unsteady, spindly sapling requires support at this early stage and wooden stakes should be used so it grows erect.

It is important to use the correct fertilizer that contains nitrogen, phosphorous, and potassium. Again, this is vital for optimum growth and the tree’s well-being.

If in doubt about the exact quantity and timing, consult an expert.

Cashew Nut Pronunciation

Probably the easiest way to pronounce cashew is to break the word in two and pronounce the KA first, followed by SHOO. Ka-Shoo will then accentuate the word properly. Nuts is just nuts.⁵

Cashew Tree Cold Tolerance

Originally grown and reared in Brazil, cashew trees are accustomed to bathing in tropical sunlight for 6 hours with temperatures above 15°C or 59°F. It can even thrive at 40°C 105°F without breaking a sweat.

Try and grow these sun worshippers in temperatures that drop below 10°C or 50°F, will freeze the sap in their veins and they will quickly shrivel and die.

Cashew Tree Guide: Can You Eat a Cashew Apple?

A cashew nut tree doesn’t just grow a tasty morsel for snack time, it bears a cashew apple and together they have a slew of benefits and uses.

Although very perishable, the cashew apple, which is actually the pear-shaped fruit that the shell of the nut is attached to, is edible. Vitamin-wise, it has a high level of vitamin C, vitamin B1, calcium, and even iron.

The nut itself is known to help sufferers with type 2 diabetes control their blood sugar levels and is often blended to make cashew nut butter. Once it is puréed it can be used to make sauces, ice cream, and even cream for soups.

In many Asian and African countries, the entire tree has a multitude of medicinal applications.

For instance, in West Africa and India the leaves are used to reduce the fever caused by Malaria and to treat gum diseases, while the bark is used topically to combat snake bites.

Cashew Fruit Uses: Cashew Fruit Benefits

The popularity of the cashew nut goes far beyond its taste. Apart from being good for sore throats, it is great for bone strength and far, far more, such as for:

• Juicing the fruit, bark, and leaves to treat diarrhea
• Making a syrup for coughs and colds
• Ingesting the apple juice for treating cholera, kidney problems, and even syphilis
• Removing warts and corns with the caustic liquid
• Alleviating painful skin cracks
• Using the thick brown tree sap as inks and varnishes as it blackens naturally
• Fabricating glue from the stems
• An insect repellant from the gum of the bark
• Using the toxic oil in the shell to waterproof woodwork
• Manufacturing plastic products
• Fermenting the cashew apple to turn it into alcohol

How Many Cashews Can a Tree Produce?

It will take up to 10 years before a cashew tree has produced to its fullest potential. It starts to harvest after two years if grown from a grafted tree, but really hits its best years at age 10, and can produce 50 kg to 100 kg of nuts yearly.²

When it reaches 20 years old, its ability to produce fruit is at an end, and it can only watch as the surrounding youngsters continue to bear fruit.

Nuts: How Are Cashews Harvested? (How To Know When To Harvest)

The color of the cashew apple and shell is the giveaway, as well as when the occasional fruit starts to fall from the branch. But generally, when the cashew apple has a change of color from yellow to a dark pink and the nutshell darkens,⁶ it’s time.

(Image: Giovanni42¹⁰)

At this stage, both the cashew apples and nuts are collected and go their separate ways. The fruits are washed, transported to local markets, sold, and eaten raw.

They taste similar to mangoes but due to their thin skin, the cashew apple perishes quickly so it is often made into a juice in its native Brazil.

The harvested nuts head in another direction still encased in their shells.

Processing of a Cashew Nut

Arriving at the processing plant, the nuts are roasted either in steam or boiling oil to remove a substance called urushiol, a substance harmful to humans. Afterward, they are finally shelled, dried, peeled, then roasted again to instill the flavor.

A second roasting may be omitted if they are being sold raw, but the second roasting process also removes any traces that may remain of the urushiol.

There can be no doubt that the cashew nut is power-packed with beneficial nutrients, helping to reduce inflammation and prevent diseases due to its high content of antioxidants.

But more than that, they just taste good.

Cashew Nut Tree Warning

In an ideal world, the cashew nut tree would grow a warning label alongside each fruit as it matures and is ready for harvesting.

It is easy to forget for the casual grower, that the nut encased within the shell is immersed in a toxic liquid called urushiol. This reddish-brown, oily substance, if coming into direct skin contact, will cause blistering and a severe allergic reaction.

This allergic reaction is similar to the skin rash received when exposed to poison ivy and the severity can vary from mild to severe depending on the sensitivity of the person.

Cashew Nut Allergy: The Cashew Nut Oil

The caustic reaction promotes a mild itchy skin condition, inflammation around the infected area, and pus-leaking surface bumps as well as a harsh burning sensation.

(Image: Philipp Legki¹⁷)

If this substance leaks out onto the shell, all these symptoms could be experienced during harvesting. To this end, care needs to be taken during harvesting, with protective clothing being used.

A further note of caution needs to be added when it comes to burning any part of the cashew nut tree. The smoke may contain traces of urushiol from burning the sap, the leaves, or the flowers, and this can be poisonous if inhaled.

It is important that people realize that this tree it is not possible to just pick a cashew nut from a tree,³ shucks it out of its shell and you’re good to go. Try that and the only place you’ll be going is a quick trip to the hospital.

Are Cashews Poisonous?

Cashew nuts are safe to eat. The only portion of the nut that can cause allergic reactions, is the urushiol oil that surrounds it in the shell.

Problems could arise if a shell is picked from the fruit, broken open and the nut eaten directly, with blisters and rashes similar to those from poison ivy breaking out quickly.⁴ Fortunately, cautionary instructions on how to pick and when to eat are given to new growers.

In the processing plant, this toxic element is safely removed and the nuts are prepared for human consumption. It is highly unlikely that any residual urushiol oil will remain to cause any adverse reactions after this careful process.

Types of Cashew Trees

Gigante and Tardio are the two main types of cashew trees grown, the first named because of its large size, the second because of its late fruit bloom. These are the traditional sizes, but in Brazil and India, they have cultivated the dwarf cashew tree that is gaining in popularity.

(Image: Sarangib.⁹)

These trees yield 5 varieties of nuts, ranging from the W-180 grading, which is the largest, to the W45, the smallest.

The price for them on the market is based on their size, but even so, the lengthy production process can make the cashew nut an expensive treat at the end of the day while relaxing with a cold beer.

Dwarf Cashew Tree: Dwarf Cashew Tree for Sale

The dwarf version was cultivated primarily so farmers could increase the number of trees they were able to plant in a given area. Being more compact and requiring less water makes them more commercially viable.

The actual nut is the same size, and for the same area of land that a farmer could plant a traditional cashew tree, he can now harvest over twice as much with a dwarf tree.

Dwarf Cashew Tree Size

In a sense, a dwarf cashew tree is superior to its bigger compatriot.

Not only can it be packed in a denser formation, but it gradually grows to a maximum height of 20 feet over a 10-year period. It requires less water and within the space of just one year, it reaches maturity and produces fruits ready for harvest.

Dwarf Cashew Tree Seeds

Before sowing the dwarf seeds, it is recommended to soak them in water for better germination. Once placed in a bag filled with a soil mixture of soil and compost, place them in a 2.5 cm hole, and just watch them grow.

Cashew Nut Family

The scientific name for a cashew nut is Anacardiaceae.¹ It has 860 familial relatives known as the sumac family, which comprises the pistachio nut, certain species of plums, mangoes, gum trees, and even as diverse a cousin as poison ivy.

Where Can I Find a Cashew Tree for Sale Near Me? Find Cashew Trees for Sale

Florida, Hawaii, and Puerto Rico are in the perfect planting zones for growing cashew trees in the United States.

But if you don’t live in any of these zones that are cashew tree compatible, and you really want to grow a cashew tree in your greenhouse.

The following list of state local growers is just a guide. Always search for a nursery nearby if possible, to reduce the carbon emissions generated by shipping and packaging.