The formula
On a rectangular or square grid, the number of plants per hectare is 10,000 divided by the product of the two distances: row spacing and in-row spacing, both in meters. A 7 × 7 m spacing gives 10,000 / 49 = 204 trees per hectare; 6 × 5 m gives 333; 3 × 1 m, typical for agave, gives 3,333. In acres, multiply trees per hectare by 0.405.
On a triangular (equilateral) grid, where every plant sits at the same distance from its six neighbors, 15 % more fit: 10,000 / (0.866 × side²). With a 7 m side that is 236 instead of 204. In practice the triangular grid is rarely used in mechanized orchards because it complicates machinery passes.
Common spacings per crop
Hass avocado. The traditional spacing in Michoacán is 7 × 7 m (204 trees/ha) or 8 × 8 (156). New plantings go to 6 × 4 or 5 × 5 (416 to 400) with containment pruning, and high density to 4 × 3 (833). Denser produces earlier per hectare but demands yearly pruning and irrigation.
Persian lime and orange. 6 × 4 m (416) is the most common; 6 × 5 (333) or 7 × 5 (285) on fertile soils where the tree grows large. In old orchards in Colima we measured 3.8 to 4.3 m between trees and 6 m between lanes.
Pecan. Wide spacings because of the size of the adult tree: 10 × 10 (100) to 12 × 12 (69). Many orchards plant at 6 × 12 and thin to 12 × 12 at 15 years.
Blue agave. Rows 3 to 3.5 m apart and plants 0.9 to 1.2 m apart: between 2,400 and 3,700 plants per hectare. Planting density is one of the variables that moves piña yield per hectare the most.
Plants per hectare calculator
Theoretical density over planted area; subtract roads and unplanted zones to get plants per hectare of plot.
Why the real count does not match the theoretical one
When we inventory an orchard by drone, the real number of living trees is almost always below the theoretical density, and sometimes above. The most frequent reasons:
- Gaps and replants. Between 3 and 10 % of the positions are empty or hold a tree of another age. In the mosaic they show as gaps in the row or small canopies among large ones.
- Roads, ditches and edges. Not all of the plot surface is plantable. In a 10 ha plot it is normal that 0.5 to 1 ha are roads and maneuvering areas.
- Mismeasured area. Deeds and registries often carry areas that do not match the real polygon. We always divide by the flown area, not the one on paper.
- Irregular spacings. Orchards planted in several stages mix spacings; the average misleads. That is why the inventory is delivered per block.
How to use density in your inventory
Theoretical density is useful for three things: estimating how many trees to expect before the first flight, spotting blocks with many gaps (real count far below theoretical) and computing linear meters of row to budget irrigation, pruning and harvest. Our inventory delivers all three numbers per block: trees counted, real density and meters of row.
Frequently asked questions
Does density include roads?
The formula gives plants per planted hectare. If you want plants per hectare of plot, subtract the area of roads and unplanted zones first; in orchards it is usually 5 to 10 %.
Which spacing do you recommend for a new avocado orchard?
It depends on irrigation and on whether you will prune every year. Without irrigation, 7 × 7 is still the safest; with irrigation and pruning, 6 × 4 or 5 × 5 produce earlier per hectare. Our plot design module simulates costs and harvest for each spacing on your terrain.
How do you count trees from the flight?
We detect every canopy on the orthomosaic, measure it and group it into rows; gaps show up as missing trees. A person reviews on screen whatever the image leaves in doubt. It is explained on the plant and tree counting page.
Other guides
- How to fly an orchard with a drone for tree counting
- From orthomosaic to inventory: what you can and cannot measure from the air
- NDVI vs NDRE in perennial crops: when each index lies to you
- Orchard yield estimation: age, density, canopy and past harvests
- Frost in cold hollows: why the forecast says 4 degrees and you wake up to ice
- All guides