When it comes to shredding trees, yard waste and similar debris, you need a whole new class of shredder. Chippers or chipper shredders, sometimes known as tree shredders, are available at a wide range of power and price points.
Commercial chipper shredders, the models that many municipalities, tree-trimming companies, arborists and landscaping professionals use, cost thousands of dollars and can make short work of tree trunks, large branches and so on. PTO chipper shredders, are equipped to use a tractor as a power source and are used in farm settings and by groundskeepers. Because a PTO (power take off) chipper shredder doesn't have its own power source, it will be less costly than a model that does. Chipper Shredder Brands include MTD, Wood/Chuck Chipper Corp., Asplundh/Altec, Vermeer Manufacturing Company and Bandit Industries. For large-scale home or business projects, commercial chipper shredders can be rented, as can less intimidating models.
There are fairly heavy-duty combination chipper-shredders available for home use (such as with pruning and landscaping tasks) that run from $400 to $800, depending on RPMs, horsepower and other factors such as the number of blades and shredding knives. Some higher-end models marketed for high-end home or small-scale farm use, such as Merry Mac Tow-Behind chipper/shredders, can run $1,500 to $3,000. These shredders typically have a chute for feeding in branches and a hopper for tossing in leaves and twigs. Features may include filter screens, the ability to re-circulate debris for another pass at being shredded, and a collection bag. Some also mulch. Chipper shredders are available at hardware stores and chain retailers like Sears and have names such as Bear Cat, Troy-Bilt, Earthquake, McCullough
There are a few compact shredder models on the market that run on electricity or gas and cost as little as $200 (such as the Grizzly G0595 and the McCullough MCS1400), but reviews are mixed as far as their durability, power and how much they can handle. These shredders usually have wheels and are promoted for home use as a way to chop up very small branches and other yard and garden waste for composting or disposal without the stress on the back or the need to use hand tools.
With shredders such as these, safety is paramount. Get trained on equipment use, use safety goggles and follow all safety guidelines to protect yourself and others.