How many trees per hectare?

How many trees do I need for my healthcare site? 

Assessing your planting area/s 

Your site’s scope for trees will be limited by the amount of land available, so the first step will be to establish the approximate area to be planted. It is possible to calculate area from physical on-the-ground measurements, but we recommend using one of the many free online digital mapping tools to plot potential planting areas over satellite imagery. For example, Google Earth has an inbuilt measurement function based on user defined polygons.

Don’t forget to exclude areas that won’t be planted such as buildings, paving and roadways, existing tree cover, and planned open spaces within the new planting. If you are considering multiple locations, it is most straightforward to measure the smaller parcels of land individually. 

A quick note about units: there is no ‘correct’ unit of measurement, but hectares (abbreviated ha) are the decimal unit most commonly used to quantify tree cover. A perfectly square hectare would have 100-metre sides, and is equal to 10,000 m², 0.01 km², or roughly 2.5 acres. 

Planting density and tree spacings 

With your measured areas in mind, the number of trees that will fit can be determined based on the planting density, or the number of trees per hectare of planted land. Densities will vary depending on the species and use of the site, but between 1,000 and 2,500 trees per hectare is common for broadleaves and a native amenity woodland might contain 1,600 trees per hectare. The density will in turn dictate the spacing between trees as planted: 

	Tree spacing		Total number of trees
	Metres	Feet	Per hectare	Per acre  (0.4 ha)	Tennis court  (c. 0.02 ha)	Football pitch  (c. 0.64 ha)
V. dense	1.0 m	3 ¼ ft	10,000	4,050	200	6,450
	1.5 m	5 ft	4,450	1,800	85	2,850
Recommended	2.0 m	6 ½ ft	2,500	1,000	50	1,600
	2.5 m	8 ¼ ft	1,600	650	30	1,000
	3.0 m	9 ¾ ft	1,100	450	20	700
V. sparse	3.5 m	11 ½ ft	800	325	15	500
	4.0 m	13 ft	625	250	10	400

The native bundles are NHS Forest’s most popular tree offer, and come in fixed sizes (10, 30, 60, 120 and 240 trees). Based on the common planting densities outlined above we recommend the following as being the minimum areas needed to accommodate each bundle size (excluding any open space): 

Bundle size	Trees	2.0 m spacings		2.5 m spacings		3.0 m spacings
Extra small	10	0.004 ha	40 m²	0.0065 ha	65 m²	0.009 ha	90 m²
Small	30	0.012 ha	120 m²	0.019 ha	190 m²	0.0275 ha	275 m²
Medium	60	0.024 ha	240 m²	0.0375 ha	375 m²	0.0545 ha	545 m²
Large	120	0.048 ha	480 m²	0.075 ha	750 m²	0.109 ha	1,090 m²
Extra large	240	0.096 ha	960 m²	0.15 ha	1,500 m²	0.218 ha	2,180 m²

Planting patterns and species distribution 

Once you have determined an appropriate number of trees for your site you will also need to consider the best approach to setting out these trees within the planting areas. There is no one size fits all approach here, and your choice will likely be informed by aesthetics and intended use. 

Tree planting: strict grid (A), offset grid (B), wavy lines (C) and ‘random’ distribution (D) 

It is quickest to lay out the trees in rows and this makes keeping track of the spacing more straightforward; however straight lines can produce an artificial ‘pyjama stripe’ effect that may not be aesthetically pleasing (albeit useful for access and maintenance). Truly random distribution is difficult to achieve in practice without creating clumps of denser tree cover, so NHS Forest recommends the ‘wavy line’ approach to give an impression of naturalistic tree cover with more even tree spacings. 

It is good practice to mix up the trees and avoid large single species blocks; small groups of the same species mixed together, with larger trees towards the centre and shrubbier species around the perimeter of planting areas will look more natural as the trees establish. 

What about shelterbelts / hedging? 

Shelterbelts are linear bands of dense tree cover. Planting 3 – 5 rows of trees with 1 – 2 metre spacings will give the shelterbelt enough mass to be effective as shade, shelter or screening. 

Hedgerow planting is also linear although the spacings will be a lot tighter than for tree cover. There are two common approaches to hedge planting: thinner single row and denser double row. 

Hedge planting: single row (E) and double row (F) 

We recommend c. 5 stems per metre of hedging – so for a single row place the trees 30 cm and for double row in a zig zag pattern with 45 cm spacings; the two rows should be 50cm apart. 

What about orchards / fruit trees? 

Orchards are traditionally planted in a grid layout for ease of access. Spacings will depend on the vigour of the rootstocks, but a minimum area of at least 0.01 hectares (100 m² or 0.025 acres) would be required to accommodate 10 trees with dwarf rootstocks and we generally suggest at least 200 m² (200 m² or 0.05 acres) per 10 trees for a more traditional community orchard. 

You will need to leave broad avenues between and around the fruit trees to allow for fruit collections; it’s preferable to encourage fruit trees to grow outwards rather than upwards for ease of harvesting. 

Advice, guidance and next steps 

We hope you have found this guide informative. If you’d like to read more about tree planting you can also read our guidance pack.

If you are feeling inspired, why not take the opportunity to learn more about NHS Forest’s free tree offers for the coming planting season?

And please get in touch if you have any questions or would like to talk through a planting proposal; just complete the contact us form or email info@nhsforest.org and we’ll be in touch.