Generally, wherever a tree starts its life is where it stays. But then how does a large, mature tree get from a nursery to a local garden center? It's plucked from the ground by a post-hole digger on steroids, that's how.
Tree Spades come in a variety of sizes and blade styles depending on the species and height of the tree—anywhere from 12-inch-diameter spades up to a whopping 118-inch model. They can be mounted on many common construction vehicles, from Bobcats to flatbed trucks. And while there is design variation between companies, most tree spades operate with a four-blade system.
The spade's four blades are mounted onto hydraulically-powered towers. The towers are fixed to a circular hinged frame, which allows the blades to surround the tree on all sides. Once the spade is properly positioned around the base of the tree, hydraulic rams plunge each blade sequentially into the earth. A nozzle pumps water onto each blade to help lubricate the process.
When the blades dive in and converge, several feet underground, directly beneath the tree trunk, the tree is then lifted from its hole and transplanted. In the case of truck-mounted models, like the Arbor Co 2100 Super Spade from the video above, the entire tree is hoisted onto the bed of a truck for transportation. Larger units, like the Dutchman 100-inch TruckSpade, can gouge a 15-inch diameter tree from the ground, along with its 15,000-pound root ball, in a matter of minutes.