The definitive homeowner’s guide to pruning and trimming your garden trees

Decades working on our leafy neighbours throughout London, Essex and south Hertfordshire has given me a unique appreciation for how thoroughly diverse, complex and valuable trees are. Tree surgery is not just what we do, it’s who we are, so whether we’re working on your trees or not we’re always keen to share the knowledge we have acquired over the years to help homeowners, tenants and landowners to look after them properly. And, as pruning can either improve the health and life expectancy of your shade-giving trees, boost the yield of your fruit trees and the growth of your saplings, or kill off what’s taken hundreds of years to mature in your garden, this guide is an important first read.

Tree surgery is blighted by the many cowboys out there who hack and tear at limbs, strip crowns and chop down trees unnecessarily and there’s just so much poor advice out there that will lead to homeowners doing more damage than good. We therefore wanted to put together a guide, brief though it may be, on a few of the most important aspects of pruning, so anyone could attempt to do the simpler aspects, or at the very least recognise when a cowboy is doing it wrong so you can eject them from your premises.
 
So, here are our 6 top tips to pruning, the right way:
 

1. When to prune

The quick and simple answer is autumn/wintertime. The reason being that pruning causes wounds on the tree which need time to heal. In that time the tree is more vulnerable to moulds, burrowing insects and fungus taking hold or invading through that wound. However, in winter there are fewer of these pests around, reducing the risk to the tree. Of course there are exceptions to this rule, but you can ask your friendly neighbourhood arborist about this.
 

2. To trim or to move?

Trees grow: this may be an obvious statement to make, but some people plant their trees in places that just aren’t suitable. So, if you find yourself having to prune your trees back every year because they are extending into walkways, windows and pathways, then you may do your tree a better service by moving it (if it’s still young enough to do this without significant risk to its health). Trees grow, and different trees grow at different rates, so if your tree is too close to a path or property, let it flourish by moving it somewhere it can without you having to tinker with it all the time.
 

3. Don’t touch the collar

When you remove a branch it’s important to leave the branch collar intact. This is the wider area at the base of the branch, which on some trees looks a little like the woody version of a roll-neck collar on a jumper. The reason for this is that if you leave a branch stub, or if you cut your branch too flush to the trunk or parent branch then it will take far longer to heal, leaving it far more susceptible to infection or invasion. There is most definitely a right way and a wrong way to prune. The wrong way can not only compromise the health of the tree, it can in some cases have a permanent impact on its well-being.
 

4. Wound dressing

Removing a branch, just like cutting into any living thing, will create a wound which can either heal quickly and nicely, or it can get infected. For years it was common practice to paint a dressing on these wounds to prevent infection, but although the jury is still out on this one, it seems that some dressings can actually make matters worse by speeding up the wood’s rotting. So, these days we do not dress wounds, we simply make sure that they are as small as possible, as well cut as possible with equipment that is as sharp as possible and as clean as possible to avoid transmission of contaminants.
 

5. Crown thinning: the 10% rule

Trees are complex living organisms: throw them just a little off kilter by over pruning them and you could be limiting their life expectancy. Trees feed from root and leaf, so when you remove too many leaves by over pruning you are throwing a spanner in the photosynthesising machine that keeps the tree alive. A healthy rule to live by, unless you have professional advice otherwise, is never to remove more than 10% from the entire crown of your tree, especially in the case of older trees.
 

6. The 3-cut pruning method

Professionals do their best to minimise the chance of damage to your trees while pruning, which is why the 3-cut method is so commonly used.

• Cut #1: Cut a shallow notch, no more than 1.5 inches deep, on the underside of the branch where it meets the branch collar. This prevents the weight of a partially cut branch from tearing down into the collar tissue, creating a larger wound that will take longer to heal.
• Cut #2: Cut the branch from its top surface all the way through, but start just a little further up than the notch you just cut to avoid the possibility of breaching this safety net against tearing tree tissue. You’re now left with a short stub between branch and branch collar.
• Cut #3: Cut off the stub.

 
We’re considering producing a longer guide with a thorough step-by-step process, diagrams and more top tips, so if you’d be interested in such a thing do let us know. In the meantime, should you need any further guidance or a trusted local tree surgeon to manage the maintenance of your trees, give us a call, we’d be delighted to help.
 
And so, to summarise:
 

Only prune in winter		Most trees should be pruned when the risk of infection and infestation is at its lowest.
Only cut into branch tissue		The branch collar is actually parent branch or trunk tissue, so don’t cut into it.
Don’t dress pruning wounds		This can hinder the healing process in some cases, so we wouldn’t recommend it.
Don’t prune too much off		Over-pruning can actually damage your tree, possibly permanently.
First cut a notch on the underside		This will prevent the tree tissue from tearing when you cut the branch off.

 
 
To book a free survey and consultation with one of our ARB Approved arborists for advice on your trees or to book in our tree surgeons to prune/maintain or fell your tree(s), call us on 0208 292 8992.