Aerial Tree Pruning

Pruning course for aerial work (CS40) for effective pruning techniques from a rope and harness to crown thin, reduce or lift a tree canopy.

Aerial Tree Pruning

(formerly CS40)

Whether you have been carrying out aerial tree pruning for years or are just getting going in the world of arboriculture/tree surgery. Nevertheless, there is always something new to learn that will help you get to where you want to be and complete jobs to an even higher standard. Aerial tree pruning is about taking your time to achieve the best outcome possible for the tree, despite what the customer is wanting you to do!

The Aerial Tree Pruning CS40 course is one of those courses where you may be thinking:
  • ‘do I really need to do this one’,
  • ‘pruning is obvious isn’t it?’ 
  • ‘how can there be a course just for pruning trees’
  • ‘you just lop it off, jobs a good un!’

Hopefully, you’ve worked past the above comments and can see the importance of correct pruning. In, above all, it is about the health of the trees you are working with. Through correct aerial tree pruning, you can prolong the life of the trees and limit the potential of infection such as pests and diseases entering and weakening the tree.

No doubt you will have seen for example the ‘pineapple’ effects after pruning. Often this is due to the tree getting stressed and undoubtedly finding a way to cope with that stress.

Therefore if you are wanting to know how to not only carry out aerial tree pruning for the benefit of the tree but furthermore create possible repeat customers then you are in the right place. 

Covering specifically but not limited too: 
  • crown thinning
  • lifting a crown
  • crown reduction
  • pollarding

Our 2-day aerial tree pruning course above all allows you plenty of time to learn about and make comparisons about the different equipment that can be used. Along with carrying out correct cuts and finally understanding target pruning ready for the assessment on the 3rd day.

The aerial tree pruning CS40 course is one of the aerial units where you won’t be using a chainsaw. The course is completed through the use of secateurs, loppers and pruning saws such as silky saws. 

Many of you are already actively carrying out aerial tree pruning tasks. However, you may have discovered that as a professional operator you need a certificate of competence to enable you to carry on doing so and keep your insurance. Above all though carrying out the right cuts to ensure the longevity of the tree for years to come. 

You may have been asked by:
  • your membership body e.g. Arboricultural Association 
  • your employer
  • or a new contract opportunity to demonstrate competence through certification

Are you new to the job or been doing it for over 40 years and things have changed, if so and you are planning to gain your aerial tree pruning CS40 qualification have you been:

  • struggling to find the right fit in terms of a training provider?
  • confused by all the names, numbers and acronyms for the land based courses that are available to you?
  • worried you will get it wrong or waste your hard-earned money?
  • concerned that it will feel like going back to school?
  • looking to gain a qualification to continue with jobs because legislation has changed?
  • offered a new and exciting contract, but need another ticket/qualification to seal the deal?
Aerial tree pruners, we can help you!

No matter which sector you are coming from, and the level of experience. We can work with you to understand your training needs. To tailor a programme and provide courses that will be suitable for you.

Providing award-winning training through tailored, flexible, friendly, approachable trainers and assessors.

All courses run with small groups to ensure you have as much time as needed to learn and experience what is required for the assessments if you chose to take them. Trainers and assessors have the experience, are friendly, and approachable.

Finally, as with all Lowe Maintenance courses, you get support and advice via email or on the phone, if you need it in the future, just because you’ve completed the course doesn’t mean you can’t get in touch if you need more information or guidance.

City and Guilds accreditation

Is the certificate you will gain on successful completion of your aerial tree pruning assessment. 

A  two-day course, with a third day for the assessment.

Group sizes are no more than four candidates to one trainer, so nice small group sizes. To allow for plenty of discussion and questions. 

You will have access to the Lowe Maintenance portal on booking where you will find leaflets and updates to look through before attending the practical session. 

On this aerial tree pruning course you will be learning about:

  • assessing the risks involved
  • what you need to do in an emergency
  • how health and safety legislation will affect you, specifically in respect of the two-rope climbing system
  • biosecurity and furthermore the importance of clean tools
  • importance of sharp cutting tools
  • identify an occupied tree, and signs of activity of birds, bats, squirrels, and wasps!
  • identifying cavities, decay or decay fungi
  • deadwood and broken branches
  • the implications of dead or flaking bark
  • awareness of power lines or telephone wires
  • things not to hit! So, in other words high value targets and obstacles underneath the tree such as greenhouses, sheds etc

You just need to bring your arborist climbing helmet and tree climbing kit with current LOLER inspection records. 

Bear in mind that this course is physically demanding and requires the carrying of equipment in woodland and countryside environments. You will have to carry the kit and equipment, you have been issued.   

Candidate portal

On booking your course you will be given access to the candidate portal, where you will find lots of leaflets and documentation to read through, ideally before you attend the course. This helps you with the terminology during the course and gives you a heads-up of what to expect in any discussions and practical sessions. There could even be some videos we need you to watch to help embed your learning in preparation for your assessments. 


The aerial tree pruning course is two days, and on a third day, you will be assessed by an independent City and Guilds assessor. 

We may be stating the obvious and it is sad that we have to be saying this as it appears it is not common practice. 

When attending a course with us, you must follow any instructions that are given when using any equipment and carrying out tasks, for the safety of all involved. 

For further details please see our terms and conditions for courses.


Other courses of interest to you


Pruning is a way of removing branches that are causing harm or damage to the tree.

It is a way of reducing weight in the tree without encouraging heavy regrowth.

As a result the type of tree decides the severity of the pruning how much you can do at any one time.

Clearly, it is easy to ruin and destabilise a tree by just hacking away at it

Yes, a proper pruning cut can allow the tree to self-protect. Yet if you hack a branch off and leave a large wound then it will encourage pests and diseases to enter and therefore damage the tree in the long term.

CS39 is more to do with cutting bigger wood that is hard to control, whereas

CS40 is for when you can easily get to points of the tree that are in need of thinning out and the wounds are better put in with a thin blade than trying to cut a little twig with a chainsaw.

Depending on the work you are doing not always. Although, it is being used a lot more by railway and utility companies, as they have realised that a properly pruned tree lasts longer and is easier to manage. Whereas a tree that has been sided off with no regard for pruning techniques is therefore at greater risk of failure.

Yes. The pre-requisite for aerial tree pruning 21-07 (CS40) is the aerial cutting of trees with a chainsaw using free fall techniques 21-08 (formally CS39). Therefore if you have passed CS39 you can do CS40. Besides, they cover different topics. nevertheless it’s quite a straightforward next step.

Of course you can but it will be a lot to take in. Although the assessment fee may be a bit more as the assessor can only do a certain number of tests per day.

However, we would recommend doing them separately. So that you learn everything required in a reasonable time frame and you are not putting excessive pressure on yourself.

There is no lowering involved in this unit even so it is best to have someone on the ground in case you have a hand saw strike and need assistance.

Crown thinning removes all the crossing limbs and thin out the canopy of the tree to let air through and limit the weight of the tree while keeping the shape of the tree.

Crown reduction reduces the overall canopy to a manageable size and staying within the percentages required to keep the tree healthy.

Whereas a crown lift removes the lower limbs of the tree to allow movement around the base of the tree. This does not have to be a large limb just taking off some side branches will allow the main branch to lift.

In spite of what many people may think there is no rope work or rigging is covered in aerial tree pruning. Whereas the rigging and rope work is covered in aerial tree rigging 21-09 (formally CS41).

The main cutting tools used are loppers, secateurs and handsaws, although sometimes a chainsaw is used to deal with bigger limbs.

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