What a Field Nursery Needs to Harvest Trees
Field-grown trees earn their money the day they leave the row. Every piece of tree nursery equipment exists to do one of four jobs: dig the root ball, lift it, move it, and hold it until it ships. Equipping a nursery well means covering all four without buying machines that sit idle.
- Digging: a nursery tree spade or nursery digger cuts a root ball of fixed size around the trunk.
- Lifting: a carrier, such as a skid steer, tractor, loader, truck or trailer, raises the spade and the root ball out of the ground.
- Moving: the tree travels from the row to a staging area, a truck, or a customer’s site.
- Holding: dug trees wait somewhere stable while the spade goes back to digging.
The carrier you already own and the way trees leave your property shape the decision as much as the spade does. For a primer on how a spade cuts and lifts a root ball, see Big John’s guide to tree moving and tree diggers. This page stays on the production side.
Start With the Inputs You Control
No acreage figure tells you what to buy. Two nurseries of the same size can need different machines because they grow different stock in different ground. Frame the decision around inputs you control.
- Caliper range. The smallest and largest trunk diameters you dig and sell, now and in coming seasons.
- Annual dig volume. How many trees you harvest each year, and how many of them fall inside a short dig window.
- Soil. Worked, prepared rows dig very differently from unprepared, hard, rocky or heavy ground.
- Carriers you already own. A skid steer and its auxiliary hydraulic flow, a tractor with a three-point hitch, a wheel loader, or a truck.
- Labor. Who runs the spade during the dig season, and how much experience they have.
- Where trees go. Moves within the nursery, loading out to buyers’ trucks, or delivery and planting on job sites.
These are the same questions a factory spec advisor will ask, so have the answers ready.
Matching Spade Size to the Calipers You Grow
Every spade model cuts a root ball of a set width and depth. Size the machine to the largest caliper you dig regularly, not the one oversized tree you might sell once. Too small a spade strips roots the tree needs. One far too large adds weight and carrier strain on every dig.
The American Standard for Nursery Stock, published by AmericanHort as ANSI Z60.2-2025, sets out recommended minimum root ball diameters by caliper for field-grown trees. It also notes that coarse-rooted plants, infrequently transplanted stock and trees dug out of season need a larger ball, while root-pruned or frequently transplanted stock may justify a smaller one.
That matters for equipment. Your root pruning and transplanting practice changes how much ball your buyers expect, and so the spade you need. When a buyer’s specification calls for a particular ball diameter, it governs.
Measure caliper the way the standard does. For field-grown trees it is taken six inches above the ground, up to and including the four-inch caliper interval. If the trunk measures four and one-half inches or more at six inches, measure at 12 inches instead.
For a quick estimate of ball size and the matching model, use the tree caliper to root ball calculator. Big John’s spec pages list the trunk diameter range and root ball size for its skid steer, loader, trailer and truck models. A sample across those carrier types:
| Model | Carrier | Trunk diameter | Root ball (width x depth) | Machine weight |
|---|---|---|---|---|
| Model 20 | Skid steer | 1 to 2 in. | 20 x 14 in. | 1,200 lbs |
| Model 44 | Skid steer | 1 to 4 in. | 44 x 36 in. | 2,000 lbs |
| Model 54 | Skid steer | 1 to 5 in. | 54 x 42 in. | 3,000 lbs |
| 42DL | Large skid steer, small loader, tractor | 1 to 4 in. | 42 x 38 in. | 3,000 lbs |
| 44DTG | Trailer | 1 to 4 in. | 44 x 36 in. | 5,500 lbs empty |
| 45D | Truck | 3 to 4 in. | 42 x 38 in. | 5,800 lbs |
| 55DTD | Trailer | 4 to 5 in. | 52 x 48 in. | 10,500 lbs |
| 65DTD | Trailer | 6 to 7 in. | 62 x 53 in. | 11,000 lbs |
Check each ball width against the minimum your buyers specify for the plant type and caliper you sell, since the standard’s tables vary by plant type. At the top of any spade’s caliper range, compare the ball it cuts with the standard’s minimum for that caliper, and step up a size when in doubt.
Nursery Diggers vs. Tree Spades
“Nursery digger,” “nursery tree spade” and “tree digger” all get used for the same kind of machine. The useful distinction is the ground it was built to dig.
Big John nursery diggers for skid steers, Models 20 through 54, are designed for prepared-ground nursery digging. They are lightweight, use cold-formed AR400 straight blades, fit a variety of skid steer loaders, and cover trees from 1 to 5 inches in diameter.
Blade profile is a choice: pointed, semi-truncated or truncated. On the Model 54, Big John offers a truncated version to reduce digging weight and height. The factory can also change blade size, number, shape or position, and add hydraulic stabilizers or adjustable leveling pads.
The Model 44 nursery digger shows the class well: trees from 1 to 4 inches, a 44-inch root ball, a 2,000-pound machine, a hydraulic gate lock and a wireless remote as standard.
Heavier spades do a different job. Big John describes its loader-mounted 42DL as made for unprepared soils, and its truck-mounted spades carry on-board water to lubricate unprepared digging. Worked rows suit a nursery digger. Hard or unworked ground is where a heavier spade earns its weight.
Carrier Options and When Each Fits
The carrier supplies the hydraulics, carries the weight, and decides how far a tree can travel on the spade. Start with what you already own. For a mount-by-mount comparison outside the nursery setting, see Big John’s tree spade buying guide.
Skid Steer
For a nursery growing 1 to 5 inch stock in worked rows, a skid steer nursery digger is the natural starting point. The spade runs off the loader’s auxiliary hydraulics; every Big John skid steer nursery digger lists a 10 to 16 GPM minimum drive system. Big John’s skid steer tree spade buying guide covers carrier compatibility by brand.
Weight is the other check. The Model 54 weighs 3,000 pounds and lifts a root ball Big John rates at 2,400 pounds, all carried out in front of the loader. Compare both against your machine’s rated operating capacity, and confirm its auxiliary flow on its own spec sheet.
Adjustable valve-body speed lets you slow the spade for a new seasonal operator and speed it up for an experienced one, which helps when dig-season labor changes.
Tractor Three-Point Hitch
If your nursery runs tractors rather than skid steers, Big John builds a three-point hitch tree spade that attaches to the front or back of most tractors. It is designed for prepared soil in tree nurseries, has a wireless remote and stabilizing pads, and maneuvers easily in small spaces.
Wheel Loader
Big John’s loader-mounted DL spades come in sizes from 42 to 100 inches and are designed for production digging in tough conditions; the company notes they are popular in sandy soils. The 52DL and 62DL call for a 20 GPM minimum drive system and ship with blank attaching plates, so expect some in-field fabrication to fit your loader.
Trailer-Mounted
A trailer-mounted tree spade tows behind a truck and is not tied to any one carrier. The lineup covers the 44DTG and the 54 trailer spade for 1 to 4 inch trees, the 55DTD for 4 to 5 inches, and the 65DTD for 6 to 7 inches, with an extendable tongue, hydraulic jack and rear stabilizers.
One caution for production growers: Big John describes its trailer line as built for occasional use, aimed at landscapers and municipal work. It fits a nursery that digs periodically or shares one spade across tow vehicles. If you plan to dig daily through a compressed season, discuss the duty cycle with the factory first.
Check the tow side too. The 44DTG lists 5,500 pounds empty and 6,850 pounds loaded, on an 8,000-pound axle with electric brakes. The 55DTD and 65DTD list total machine weights of 10,500 and 11,000 pounds.
Truck-Mounted
Truck-mounted tree spades carry the tree on the road, which matters if your nursery delivers and plants for customers. Big John notes that nurseries use its 45D, built for 3 to 4 inch trees, both for balled-and-burlapped harvest and for dig-and-deliver work. It carries a 125-gallon water tank as standard.
Above that, the truck line runs from the 55D and 65D up to the 100D for 12 to 14 inch trees, for growers who move specimen-size stock.
Moving and Holding Dug Trees: Pods and Pod Trailers
A spade carrying one tree to the loading area is a spade that is not digging. As dig volume grows, separating digging from hauling keeps your most expensive machine in the rows instead of on the road.
Big John’s tree pods and pod trailers are built for that split. Pods come in 44, 55, 65, 80, 90 and 100-inch sizes, as several pods on one trailer or as free-standing pods. A pod trailer moves multiple trees in one trip, with fewer miles and less fuel, and frees the spade during transport.
Free-standing pods, which Big John sells as pod packs, can be built to any size and attached to a skid steer. They hold dug trees in place while the digging gets done, so they work as a staging tool as much as a transport tool.
Pods can also keep the soil plug from a receiving hole containerized, which means less shovel work at planting. If trees travel on public roads in a truck spade, Big John also offers dirt skirts and mats in its truck spade sizes to keep soil on the load.
Buying New vs. Used Nursery Equipment
If you are searching for nursery equipment for sale, the used market is worth a look, provided the machine fits your carrier and caliper range. A used spade in the wrong size is no bargain.
Big John regularly lists customer trade-ins and demo equipment in its used tree spades and nursery diggers inventory, inspected and maintained before sale. Recent listings have included a 40N nursery digger, a 65-inch nursery-style digger, a 30-inch skid steer demo unit and pod trailers. Inventory turns over, so confirm what is available now.
Buying used can also get you a model that is no longer in production. Buying new lets you specify the blade profile, stabilizers and leveling pads for your ground from the start. Either way, Big John states that parts ship the same day in most cases, and financing applications are available through its sales team.
A Simple Decision Table
A starting point only: confirm fit against your carrier specs and your buyers’ ball sizes.
| Your situation | Look at first | Why |
|---|---|---|
| You grow 1 to 5 inch stock in worked rows and own a skid steer | Skid steer nursery digger, Models 20 to 54 | Built for prepared ground; 10 to 16 GPM minimum drive system |
| Your nursery runs tractors, not skid steers | Three-point hitch tree spade; confirm the caliper range with the factory | Mounts front or back of most tractors; designed for prepared nursery soil |
| Unprepared, hard or sandy ground | Loader-mounted DL spade, such as the 42DL for 1 to 4 inch trees | Built for unprepared soils and tough digging |
| You dig occasionally and want a spade not tied to one machine | Trailer-mounted spade: 44DTG, 55DTD or 65DTD | Tows behind a truck; Big John positions the line for occasional use |
| You deliver and plant for customers, or grow past 5 inches | Truck-mounted spade, 45D and up | Carries the tree on the road; on-board water tank |
| Dug trees wait to ship, or you haul several per trip | Pod packs or a pod trailer sized to your spade | Keeps the spade digging while trees are staged or hauled |
| First machine on a tight budget | Used inventory | Trade-ins and demo units; check carrier and caliper fit first |
Getting the Spec Right Before You Buy
Big John Manufacturing has built tree spades in Heber Springs, Arkansas, since 1975, and today’s lineup covers skid steer, tractor, loader, trailer and truck mounts. That range lets a nursery match the machine to its stock and its carriers.
When you are ready, bring your caliper range, annual dig volume, soil type and carrier details to Big John’s sales and service team. They can match a nursery digger, spade or pod setup to your operation, new or used, and spec it for the ground you dig.
Tree Nursery Equipment: Common Questions
What equipment does a small tree nursery need to dig trees?
At minimum, a spade sized to your largest regular caliper and a carrier that can run and lift it. A common starting point is a skid steer nursery digger on a loader you already own. Pods or a pod trailer come next, once dig volume justifies keeping the spade in the rows.
Is a nursery digger the same as a nursery tree spade?
Yes. Both terms describe the same kind of machine. Big John uses “nursery digger” for its lighter skid steer spades built for prepared nursery ground, which is what most growers mean by a nursery tree spade. “Tree digger” is a common regional name for any tree spade.
What size tree spade do I need for nursery stock?
Match the spade to the largest caliper you dig regularly and to the ball size your buyers specify. ANSI Z60.2-2025 publishes recommended minimum ball diameters by caliper. Big John’s skid steer nursery diggers cover 1 to 5 inch trees with root balls from 20 to 54 inches wide.
Can my skid steer run a nursery tree spade?
Usually, if it delivers the flow and the capacity. Big John lists a 10 to 16 GPM minimum drive system for its skid steer nursery diggers. Then add the spade’s weight to the root ball weight and compare the total with your loader’s rated operating capacity, using your machine’s own spec sheet.
Is a trailer-mounted spade a good fit for a nursery?
It can be, when digging is periodic or one spade needs to work behind several tow vehicles. Big John positions its trailer line for occasional use, so a nursery planning to dig every day of a short season should discuss duty cycle with the factory before choosing one.
Where can I find used nursery equipment for sale?
Start with the manufacturer. Big John lists inspected trade-ins and demo units, including nursery diggers and pod trailers when available, in its used equipment inventory. Buying from the builder keeps factory parts and service support behind the machine.