Dead and Dying Yew Hedges and Trees
Yew has a reputation for being indestructible, and given fair treatment, there are yew trees planted today that will still be alive when mankind (if we survive) will have escaped the solar system.
At the same time, and like any living organism, yew can die prematurely, but because it is tough you may be able to save your tree or hedge with swift action. Here are a few reasons why yew dies when it should not.
Dogs and Cats kill Yew Trees and Hedging
Well sort of. Actually it is what comes out of the back end of dogs and cats that kills younger yew trees and hedging. Cats like to excavate holes in pretty much the same place and carefully bury their excrement. It is a bit like topdressing with raw lion dung. Not a good idea and, from the tree’s perspective, slow poisoning.
Dogs are worse, in that where one dog pees, others are sure to follow. And then the first one comes back to mark their marks marking his mark, and then they return…. and yews do not like uric acid on either their roots or leaves.
Yew dies by drowning
Yew grows just about anywhere - there is a lovely yew hedge by the river Wylie that is flooded whenever it rains. But then the ground drains. The moral of the story is that you can plant a yew hedge in any kind of soil as long as the roots do not sit in water for extended periods of time. Dig a trench in solid clay and fill it with lovely compost and top soil and you have created a death trap for your hedge. The clay does not drain and the trench will fill with water and stay that way. So if you are planting on poorly draining soil either ensure there is drainage, or DO NOT PLANT IN A TRENCH. Clear the ground, and plant bare-rooted stock in slits which you close up firmly when you have finished. There is an excellent planting video on our site which shows the technique.
Salt
The salt that is spread on roads whenever there is a hysterical reaction to the possibility of freezing conditions is bad for all plants. Full stop. If your hedge is in a place where thawing ice, snow or just rain will run off, then think about a wall or fence. Most plants hate salt. If your hedge will not suffer from run off, but gets splashed, go out the day after the thaw and wash it with a hose until it has been in the ground for at least 12 months. Given our climate you probably will not have to do this at all.
Root Rot
Root rot is caused by a number of organisms most notably Phytopthora. Some form of pythopthora exists in all soils ( a bit like cold germs in tube trains…). Just because it is there does not mean your plants will die, like most diseases it needs the right conditions to cause damage. It is always best therefore to improve the soil with organic matter to help drainage and to encourage new root growth. Expensive plants like yew are also helped if you use a mychorrizal additive - it is not cheap but the benefits are considerable.
Honey fungus
As with phytopthora there are a number of forms of Honey Fungus, not all of which are dangerous to plants. However the ones that are kill any tree or woody plant whose defences they penetrate. Yew included although the number of reported deaths of yew cause by honey fungus is very few as it is extremely resistant. Honey fungus travels underground and attacks trees and hedge plants through their root systems. If you cleanly trim off any broken bits of root with secateurs before planting, and if you improve the soil with organic matter, you reduce the chance of a honey fungus attack.
Watch your hedging grow, and enjoy
July 31st, 2008 at 12:09 am
[...] presents Dead and Dying Yew Trees and Hedges posted at Ashridge Trees, saying, “Yew (taxus) hedging sometimes causes trouble in the summer [...]
September 15th, 2008 at 5:36 pm
I have over 60 dying Yew tree down to poor drainage and water logging after a particularly bad summer of rain in SE Ireland… I could cry looking at the brown and dying trees! Anyway, my husband and I spend the weekend taking them up and re-planting in a raised bed to try and save them from dying completely. Most of them are very brown, my question is should I cut back the brown and dead leaves or leave them to get established (hopefully) in their new home?? Any help would be very helpful as we are at a loss what to do with them for the best. Just out of interest I am planning on planting an Alder hedge this time around - likes wet and water logged soil I hear!?
September 15th, 2008 at 11:49 pm
Hi Liz,
Thanks for your query.
Yew first (no pun intended). They are either dead already, in which case there is not much to be done, or they are just poorly. You must work on the assumption they are poorly. Give them a foliar feed, which will boost the plants. By all means cut the really brown stuff off - yew regrows from old wood, so it won’t hurt. And be patient - even if you think they are all dead, wait at least until the spring. Yew is incredibly tough and can come back from the edge of the grave. You have done the right thing geting them out of the water - they hate it. Now let time take its course.
As for the Alder. They will grow in very wet ground as long as it drains occasionally. However Common and Grey Alder in particular are susceptible to root rot (Phytopthera). If any of your yew had mushy black roots when you lifted them, I woudl be inclined either to plant Italian Alder, or to use willows to be on the safe side.
Hope this helps -
Good luck
Julian
September 16th, 2008 at 1:32 pm
Julian, Thank you for the comments, it gives me some hope as the trees were so beautiful to begin with. The ground is very wet but does drain eventually, climate changes here has meant that it is extremely more soggy than normal. The Yew for the most part still held the size and shape of the pots they came from when I pulled them up -with the exception of the very evidently dead ones which had practically no root left. So maybe they will survive. I will look at alternative alder - thanks again for the advice. Liz
September 16th, 2008 at 11:13 pm
Liz, I hope there was something there that helps. Foliar feed is a miracle worker with almost all hedging that is in trouble.
If the yew roots still were pot shaped, it either means that they were pot-bound when you got them, or the planting holes were not prepared as well as they could have been. All pot grown yew hedging likes large holes (a little deeper than but twice as wide as the pot) with good soil containing plenty of well rotted organic matter returned around the roots. The roots themselves are pretty tough and can be teased away from the root ball a bit to encourage them to grow into the surrounding soil faster.
Let us know how you get on.
Best
Julian
September 20th, 2008 at 8:55 pm
An alarming number of plants in a yew hedge planted this spring are turning brown and look as if they might be dieing. It could be that they are waterlogged after the recent very wet weather. But they are also planted under a walnut tree. I understand that walnut trees can give off a chemical that prevents some plants growing underneath them Could this be the problem for my yew hedge.
September 20th, 2008 at 11:32 pm
If the walnut is a Black Walnut (Juglans nigra) then very possibly. It would not touch an established yew, but newly planted hedging is another matter.
If you are not sure if your walnut is black walnut or not, then English and Black walnut are easily distinguished by looking at their leaflets. Black walnut leaves have between fifteen and twenty three leaflets, whereas English walnut has between 5 and nine. English walnut leaflets are much larger and oval, while black walnut leaflets are slimmer and smaller and have serrated edges.
There is not much point in moving the yew at this stage. It is an incredibly tough plant and it may be brown for other reasons (and totally brown yew can still recover). The wet weather (if you are on heavy/clay soil may also have something to do with it. Give them a foliar feed and leave them alone.
Good luck
Julian
September 23rd, 2008 at 12:21 pm
Julian,
I am trying to find a reason for a young yew hedge suffering from individual plants bronzing and whole branches dying. Hedge is 4 years old, from cell grown plants. Each year a plant will go brown and the branch is clearly dead. Trimming off the dead branches leaves a stump but some life remains and the plant looks like it may come back.
I live in North Scotland and the hedge is on a south facing slope on a clay soil. I also lost a specimin conifer to the same problem last year.
Thought I had got away with it this year but noticed one of the larger plants now a dark brown colour. We do have dogs but problem seems to affect whole branches rather than the whole plant.
Any thoughts?
Regards Alf
September 24th, 2008 at 8:33 am
Hi Alf
Yew hedging bronzes or goes brown because the yew plants in it are stressed (physically rather than mentally). From what you describe, if I had to pick one cause, it would be root rot. It sounds as if you are on clay, which drains badly and we have had a succession of wet winters and/or summers. Being cell grown plants I guess you planted your yew in holes or a trench, and either would have spent a good part of the last four years full of water. (For future reference, you may find it better to plant bare root hedging plants). They are cheaper, establish better and can be slit planted so there is no hole to fill with water and drown the roots. The is a film on our main website on How to Plant a Country Hedge which shows the technique you should use.
I hate to say this, but if you dig up one of the affected yew plants in late October, you will almost certainly it has some see soft, black rather smelly roots. If so, you might think about
- giving your yew hedge a foliar feed now to try give it a boost,
- digging up the whole hedge & trimming the diseased roots off (and burning them)
- trying to improve the drainage by digging a relief drain so water flows down the hill
- replanting and mulching heavily.
Yew is a wonderfully resilient hedging plant and your existing plants can recover if they are given a little help (and if it is not too late). But it must be worth a try.
Hope this helps, and good luck
Julian