We have bought a house that has a lovely box knott garden.  During the months since we moved in some of the box trees have started to turn yellow and now many of them are completely yellow.  As yet the leaves are not dropping off.

Picture of the hedges

 We were told that it was maybe because the soil was too damp and indeed the box's are planted in soil which has a very tight weedproof membrane and then the blue slate on top. We tried cutting the membrane back about a foot fron the edge so the box were not totally surrounded by membrane but this doesnt seem to have helped.

Interestingly many of the plants are flourishing and odd ones in the middle of yellow ones are green. You cant see from this picture but we have whole sections that are still green and much taller and stronger than the yellow ones.

Does anyone know what else we should try.

Tried again and think the link is a link to your hard drive so still cannot access it

Sorry,claire

Hi stuart, I can access the picture now by clicking on the top 'Picture of the hedges' as you suggested.

Agree with Pamela, they do not look like box, although is not all that easy to see from the distance.

Ok here are some new photos where you can see the plants mostly green on the 1st of September and then some close ups of the leaves now

http://picasaweb.google.co.uk/stuartforrest/BoxHedges#

Box Hedge Pics

Okay John, I'm sorry, your wife is absolutely right...  they are box that are desperately in need of a good haircut next year.  Box are normally a bushy, dense plant because they have been clipped.... these look as though they have never been clipped since they were planted.

How long have you lived there?   Do you have any idea how long they have been in the ground?  Is it just possible that the people you bought that lovely house from did a swift makeover on that bit of the garden to smarten it up before putting it on the market (it looks new to me as the slate is still quite new and clean) and perhaps the shrubs hadn't really got their feet down and perhaps they have (in the summer) suffered from lack of water? 

The reason they may be different (side by side) is if a shrub is pot bound when it goes in the ground it is less likely to get it's feet down and take on water.  Sometimes a small shrub will get away faster because it's not pot bound.  Sometimes when you plant a shrub the roots have started to go round and round the pot rather than down and they have a memory and continue to grow round and round instead of down and out into the soil...  Often if you dig up a shrub like that you will see that the roots are going round in a spiral instead of down.  It's the only thing I can think of to explain why they are different side by side and some are green and others not.

There is a disease that box get that does turn them brown, but now you have shown me the close up of them I'm less likely to think that is what it is.

I would just leave them for now, these recent rains will have given them all they need! and in the spring look for new growth.  If you can see that they are still alive and starting to grow again... I would give them a prune (this may seem a bit severe, but I would probably take a third of the growth off) which will encourage them to bush out from the point you have pruned them to.  In my humble opinion, they are more than big enough for a knot garden and need to be shaped now (flat top and straight sides).  They should have been clipped a little each year while they were growing and their ultimate height and width achieved after a number of years.  So give them a good trim next year and then just a little bit each year after that.

You may find you will have to replace the ones that are really brown, but it is worth waiting to see.  I have my fingers crossed for you.

Someone may have a different opinion, but that is what I would do Stuart. 

Best of luck

Pamela

P.s. Fabulous view by the way.

Stuart Forrest

Hi

Firstly the hedge should have been planted closer together. You will find that they will not join together at the bottom because of that, in other words you will have gaps. As Pamela has said they should have been pruned in earlier growth to encourage branching. When you do prune them use some for cuttings to fill the gaps.

Good news is they do not appear to have box blight. They will tolerate a clay soil as long as it is not very heavy. The most likely cause could be a lack of nutrients caused by excessive rain or failure to follow a feeding regime. Box are heavy feeders and should be fed on a regular basis through the growing season. I would suggest a feed of a balanced fertilizer either Growmore or B.F&B. Sulphate of ammonia will also green them up pretty quickly as it is very fast acting.

Bazza 

Good idea about the cuttings Bazza.

I was thinking about this lack of nutrients.... it could well be that being on top of that hill that the nutrients have been washed away and the soil isn't as good.  A good feed will certainly help.

Pamela

If they have grown rapidly since you first saw them in July 07, then that suggests that what Bazza is saying is likely.  They haven't liked all this wet weather we had over the summer and autumn and it has washed the nutrients from the soil and as Bazza says... they need a good square meal !!!

Pamela

Thanks for all the help. The general thought is that we need to feed them. We have not fed them at all and I believe the soil was brought here when they planted them last year.  It is certainly not mature soil they were planted in. 

 I will arrange to get some of this feed. Are they likely to green up even in the winter months or should we not expect that until next summer.

Do you think we need to remove the membrane under the slate (we have already cut away the first foot from the edge as we thought this may have been affecting them.

I think it rather depends of your method of feeding them.  If it were a foliar feed (diluted in water) then I would have thought it would be fine, but if you want to roughly fork in some granular food around the base of the plants I think that it might be an idea to peel back the membrane, put down the food and then replace it as it will help to work as a weed suppressant.

 I'm avoiding your second paragraph because I don't really know the answer... Bazza will tell you, he's the expert.  My gut feeling is they might.  If not feed again in spring.  From what Bazza says it sounds to me as though they are greedy feeders and will want this sort of treatment anyway and so perhaps you need to buy in bulk !!  I will get some for mine.  I've been using chicken pellets on mine and perhaps they would be better with a new diet.