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How to prune ivy

Writer's picture: ClaudiaClaudia

Updated: Dec 5, 2019


I quite often get called to gardens which have become overgrown. Sometimes they've been left untended for years (I think my record is someone who said, "I haven't really done any gardening since I hurt my back 23 years ago"), sometimes the client has just moved to their new home and is daunted by the jungle facing them, and sometimes the owners say, "We had a low maintenance garden put in by a designer and it just needs a bit of attention."


Overgrown gardens can have brambles, self-seeded saplings (or even quite tall self-seeded trees), shrubs which have become distorted and unprunable in their competition for light, an array of lost toys and sports equipment, rampant perennial weeds, and generations of annual weed seeds waiting for the opportunity to burst into life, but the most common - almost universal - problem is ivy.


R.I.P. shrubs

Ivy covered buildings are picturesque, and young ivy leaves are incredibly decorative on fences and even the trunks of trees. Ivy is a hugely valuable wildlife resource, too. In late summer the flowers hum constantly with insects, the fruit provides food for birds over a long season in winter, and a really tangled ivy provides cover and support for nesting birds. Ivy is so vigorous, though, that it can swamp everything else in its path, and in a garden the choice sometimes has to be made between having ivy, and having anything else. Ivy can even kill trees by climbing to the top and spreading over the canopy, shutting out the light and preventing photosynthesis. Imagine what it can do to all those beautiful low-maintenance shrubs that were on your designer's mood board.


This was taken outside St. Thomas' Hospital. Poor, poor designer. N.B. here you can see the adult form of the leaves.

I'm not completely anti-ivy, but I've been into enough gardens full of ivy and dead shrubs with sad labels on that I can't stress enough that it must be rigorously controlled. So, how do we do it? As always, the answer to how to keep ivy decorative and harmless lies in how it grows:

Ivy doesn't produce a strong, weight-supporting stem so in order to get as high as possible to have the best chance of breeding and out-competing its neighbours it climbs up other things using tiny adventitious roots with suckers on. Once it gets to the top of its support it will expand further by throwing out shoots sideways. If these shoots are coming from the top of a tree they will hang down and just get bigger and stronger, produce more leaves for photosynthesis. This creates weight problems and makes the tree more susceptible to wind damage. Your solution here is a tree surgeon to remove the ivy.


The closer lump is Hawthorn, and the taller turned out to be an unidentified dead tree

If the ivy is growing up a fence or wall, these young shoots from the top will drop down to the soil of your garden where the adventitious roots will penetrate the earth and grow into a proper system strong enough to support a new ivy plant should it be separated from the parent plant. This new plant will send shoots out across the surface of your flowerbeds until it finds something else to grow up, and the process begins again. This leap-frogging method of vegetative reproduction (ie, cloning) is called layering.


Ivy creeping across your flowerbed, making new little ivy plants

Meanwhile, the parent ivy plant is still sending out shoots from the top of the fence, which scramble out over the first lot of shoots, getting further away from the fence each time.



I've seen garden walls with a mass of ivy growth extending 1.5m horizontally from the top of the wall. At the same time, the ivy has stopped bothering to produce leaves on the lower stems climbing the fence, because it's getting so much more sun on the ones it's sending out from the top, so the fence you wanted to conceal is back in all it's glory.


One other thing to note is that ivy has two leaf forms, the juvenile, which is the attractive lobed leaf we all associate with ivy, and the adult, which is a simple, non-lobed leaf, which is lighter in colour, photosynthesises more efficiently and accompanies the flowers and fruit. These adult stems are produced once the ivy has got as high as it can into the sun and wants to start reproducing.


So, how do we produce a wall or fence with a close, even covering of juvenile ivy leaves? Well, if you're starting with a young plant you'll need to tie the first stems in sideways, about 6 inches from the base of the wall across the area you wish to clothe. This is because left to its own devices it will make a single beeline for the top of fence. When you tie stems in horizontally, the chemicals that cause buds to sprout (auxins) will start to work on the nodes all the way along the stem, so you will get multiple vertical shoots. (Think of auxins as the bubble in a spirit level: they always want to be at the highest point. If you take the tip off a shoot, the auxins will activate the buds at the next highest node. If you tie the plant sideways so that all the nodes are at the same level, the auxins will travel to the uppermost edge of the stem, and activate all of them at once. )



When you have your covering of juvenile stems, clip the ivy with pruning shears once a year to keep it close to the fence and cut along the top to get rid of any burgeoning overhang. If stems start to get thick and hairy, cut them off low down to encourage new shoots from the bottom.


If you're starting with a huge mass of overgrown ivy, roughly cut back as much as you can to the top of the wall. Dig up any ivy rooting through the borders and cut away from shrubs and trees. Next, cut away any large knots and any non-pliable stems that have grown away from the wall. Then cut any stems over 1cm thick down to around 10-15cms above the ground. Your ivy will be starting to look quite feeble by now, but don't worry, it still has a good root structure, and splenty of vigour. Tie in horizontally close to the base of the wall any pliable stems. Have a last trim at the top of the wall to tidy it up and step back to congratulate yourself. From now on keep it clipped close (really close! ivy grows fast!), and keep an eye on where new shoots are going.




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©2019 by Claudia Rutherford Garden Design including all images.

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