Not all trees are created equal, and neither are chippers.

You might know that white oak, hard maple, and American beech are extremely hard woods, for example, but did you know that there are some that are even harder?

Woods can range widely in density and their fibrous makeup. The types of trees you'll find listed below have some of the most difficult types of wood to chip. Your everyday chippers and chipper shredders won't be able to process them.

Instead, these require the power and efficiency of the strongest chippers, such as a commercial-grade PTO or skid steer wood chipper.

 

Hickory  

The Janka scale is a scale that measures the hardness or density of different kinds of wood. With Janka ratings in the 1800s, several species of hickory trees rank higher than even white oak or hard maple, making them extremely challenging to chip.

One of the most common types of hickory in the U.S. is shagbark hickory. Native to eastern North America, shagbark hickory produces wood that's known for being difficult to work with and capable of quickly dulling blades. There's a reason it's often used to make hockey sticks.

So why bother putting shagbark hickory (or any other types of hickory) into a commercial chipper? One word: flavor. Hickory wood chips are valued among meat smokers and barbecue pit masters for the flavor they impart in the smoker or grill.

 

Mesquite 

Hickory isn't the only kind of wood that barbecue aficionados prize. Mesquite's strong, distinct flavor makes it the mark of an experienced barbecue hound-and a boon for commercial wood processors.

But there are other reasons why mesquite (specifically honey mesquite, a kind found commonly in the southwestern U.S.) is good to harvest:

• It burns at extremely high temperatures, making it a valued firewood
• Its strength and stability make it useful for woodworkers
• It's considered an invasive species, so harvesting it helps control its spread

Just be prepared to use professional-strength equipment to break mesquite down after you harvest it. With a Janka scale rating of 2340, honey mesquite is even harder to chip than hickory.

 

Osage-Orange

You're likely to know Osage-orange by its grapefruit-sized, wrinkle-skinned green fruit, which has earned this tree the more common name of hedge apple.

Make no mistake, though. Although the fruit often clutters the ground beneath the tree, landscapers know that the wood poses its own challenges-and strengths.

In fact, because of its durability, the wood of Osage-orange trees was used to make livestock pens in the days before barbed wire was employed; today, Osage-orange is still used for fence posts and hedgerows. 

With an astounding Janka rating of 2620, however, Osage-orange isn't a wood that anyone with a consumer-grade chipper shredder can break down. Plus, due to the long, sharp spines along its stems and the sap inside its branches and fruit, which can cause skin irritation, Osage-orange is best left to the pros to handle.

 

Black Locust

Black locust isn't an invasive species within the United States. It is, however, a species of tree that will grow and spread aggressively in a favorable environment. Opportunistic might be a better word to describe it... and that might make people eager to chip it. 

But black locust is a durable wood with plenty of uses:

• Fence posts
• Railroad ties
• Wood chips for long-lasting mulch

The reason that the lumber industry hasn't invested more in these sturdy, plentiful trees is their susceptibility to the locust borer, an insect that can destroy these trees with ease. 

Due to its Janka rating of 1700, though, black locust is a type of wood that's impossible for the industry to completely ignore, and difficult for any chipper but the strongest ones to chip.

 

Bamboo

Why bother with bamboo if it's so difficult to cut or chip?

• It regrows quickly, so it's easy to replenish and therefore eco-friendly
• Bamboo chips can be used to make high-energy fuel
• The silica bamboo contains makes it an excellent mulch for soil

Freshly cut green bamboo is some of the densest wood you'll find, however. To cut through fresh bamboo, you need a heavy-duty commercial chipper with knife blades approximately four to six inches long and rectangular in shape

 

Palm Trees

Although they're beautiful to look at, palm trees are a real challenge to dispose of. Palm tree fronds and vines are some of the most difficult tree materials to run through a wood chipper.

You'll want a large commercial-grade chipper shredder for this kind of a load. The shredding capability will be useful for processing the fronds, and the commercial strength of the chipper blades will enable you to chip wood from the trunk.

 

Melaleuca 

Melaleuca trees go by a number of different names:

• Paperbark
• Tea trees
• Honey myrtle
• Swamp tea trees

Melaleuca trees are native to Australia. However, they were introduced to the U.S. via the coastline states of California and Florida, where warm climates allowed them to thrive. 

Because unseasoned melaleuca wood falls around 1530 on the Janka scale, chipping a melaleuca tree requires a large commercial-grade chipper, but it can generate supplemental income. Melaleuca wood chips are incredibly resistant to termites. As a result, they're popular for use in landscaping and can be sold to landscapers and homeowners alike.

 

NEXT: Top-Rated and Best-Selling Commercial-Grade Chippers