Healthy Hedgerows survey guidance
When can I survey?
You can do this survey at any time of year. You do not need to identify any hedge species; it is more about the structure of the hedge itself.
Healthy Hedgerows App
We have created a phone app to speed up hedge surveying. This app makes health checking your hedges in the field fast and easy. The data will be displayed on your dashboard when you log in to this website (the same login details are used for the app and this survey website). From this area, you will be able to see all your survey results displayed on a map, helping you piece the management options for each hedge into a farm scale management plan.
How to survey
Measuring the start and end of a hedge:
We need to define a ‘start’ and ‘end’ point for each hedge. For the purposes of this survey, a hedge starts and ends where:
- another hedge meets the hedge you’re surveying (on either side)
- there’s a gap in the hedge of 20m or more
- the hedge structure changes dramatically for 20m or more
- your hedge meets another feature such as a wall or woodland
- your hedge turns a corner of 90 degrees or more
Estimate or measure the average height of the woody structure of the hedge. If your hedge is on a bank, measure from wherever the woody shrubs begin to grow. Don’t count herbaceous vegetation and brambles in this measurement.
Estimate or measure the average width of the woody structure of the hedge. This can be difficult to see. Using a long stick to poke through can help. It’s best to take a couple of estimates to get your average.
The base canopy is the lowest leafy growth coming from the structural woody plants in the hedge. In cases where the hedge is extensively grazed, where it’s overgrown and ‘leggy’ or where tree guards have been left on a young hedge too long, the base canopy may not extend to the ground. Please estimate the average height of this canopy from the floor, excluding herbaceous vegetation growing underneath.
Number of trees
Please count the number of trees in the length of hedge you are surveying. A hedgerow tree is distinct, and is managed separately from the hedge itself.
Please don’t include woody shrubs that make up the structure of the hedge, only those that have a clear stem and are obvious as individual trees with isolated canopies above the height of the main hedge line.
This can be more challenging for hedges of H8 structure and above where the hedge structure plants have grown to a point that they could be described as ‘trees’. In an over-mature hedge, don’t count the plants that make up the main body of the hedge, even if they are approaching what could be classed as a tree, unless they are clearly identifiable as distinct from the rest of the hedge structure, i.e. it was likely to have been a hedge tree before the rest of the hedge was allowed to grow up.
These trees must be in the line of the hedgerow or the nearest point of the tree trunk must be less than 1m from the edge of the woody canopy of hedgerow.
Please chose which hedge structure illustration and description best matches the hedge you are surveying. Please read all the descriptions of the hedge structures
before confirming your choice. If you’re unsure description to choose, it may help to see how these stages fit together in the hedgerow management cycle, below. The heights and measurements in the hedge structure descriptions are there as a guide only, please make your choice based more on the description than the measurements.
Sometimes you may come across a hedgerow that doesn’t fit into any of these categories. If this happens, have another read through the descriptions and chose the category it fits in best, even if the description is not perfectly describing the hedge in front of you. In the cases where no structure represents your hedge, please mark ‘not similar to any of these structures’. Unfortunately, this will reduce the usefulness of the management advice generated.
There are galleries of hedge photos illustrating hedges at each of these stages on the hedgerow survey here. It may be helpful to spend a bit of time looking through these before surveying to familiarise yourself with the different structures and how they look.
A gap is any point where there’s a break in the woody structure of the hedge. Please include both small and large gaps in your calculations. Any gaps of 20m or larger should be considered the end of that hedge, see ‘Measuring the start and end of a hedge’’
Occasionally you will see gaps in a hedgerow that are starting to fill with bramble etc. These should still be counted as gaps as there is no woody hedge structure component.
At times, the presence of a large tree can cause some gappiness around the base. If the tree canopy overlaps with the hedge canopy this is not considered a gap. Only regard something as a gap if there are no overlapping canopies of woody species to maintain connectivity.
How do I use the results?
Each survey will generate some management options suitable for a hedge of its life stage. More details and tips about each of these management options can be found here. Which explains what these options are and how they will help.
It’s important to make sure you make a farm scale management plan which staggers management over time rather than doing too much cutting or rejuvenation in any one year. Ultimately, aim to for rotational management across your hedges, so that you always have different hedge lifecycle stages represented across the farm. When this is achieved, it can reduce the number of hedges that will need cutting or rejuvenating at any one time, and benefit wildlife which thrives with a diverse selection of hedge structure.
The map of your surveys will show colour coded lines which represent the hedge structures chosen, and are labelled with a code that reflects the structure, the gaps, the base canopy and the number of trees.
H2-10G-3T-HBC demonstrates that
- H2 is the strucure
- Gaps equate to 10% of the hedge length
- The hedge has 3 hedgerow trees
- It has a high base canopy
You can find some advice on how to turn these individual hedge management options into a farm scale hedge management plan here.
Some surveys may come back with inconclusive results, where the structure and the measurements do not match typical hedge stages and the app is unable to locate them on the hedge management cycle. For these hedges, we can’t give management advice options, but suggest seeking further advice.