Cupressus Arizonica

xxiamherexx

Hi. Iam a newbie so apologies for any errors. I purchased one of these beautiful trees from a reputable garden centre 18th April. But it seems like it is dying? I initially was watering it about a can a day. I have since repotted in a ceramic pot and watered only about once every 4 or 5 days. I have looked exhaustively online and cannot find an answer or remedy to help. It has no mites, still has sticky sap spots on the main stalk and I have been regularly brushing the brown crusty, dead bits off. I will be devastated if it dies. I have added a picture of when I brought it and how it looks now which hopefully helps someone reading. Any advice would be greatly appreciated. Many thanks. 

Pianoplayer

Hello. My instinct is lack of water. Trees in pots are totally dependent on the water they are given. Did you repot it using loam/soil-based medium (eg John Innes no 3)? Multipurpose compost won't be sufficiently water-retaining, so that might be making it worse.

xxiamherexx

Hi Pianoplayer, thanks for your reply. I thought that, as in lack of water, purely as it looks parched and dried out. I repotted using Aldi multi purpose soil, which I have found is not as good as it used to be, as it had a lot of wood chippings through it. Maybe I should repot and try giving it good deep watering. I did feed it with liquid food I use for my palm and topiary. So JI No3 is a good choice as I will happily repot as desperate to save it further distress. 😞 

xxiamherexx

Hi, update I repotted my tree with John Innes No3 mixed up with a bit of Miricle Gro moisture control on Thursday. Must say the JI was very wet so after drilling a few more holes in the base (as there was only one little Diddy one and no drainage) I have given it a good deep watering and will leave it and see. Although my neighbour has a garden full of conifers (all that he stupidly, imo, planted along all sides of every fence panel he has!) anyway he stopped me last night to say he had to dig one out as it had died and that there is some sort of disease in the UK this summer that is killing off greens, as in Firs? Not sure if he's just talking waff or what. So I am keeping my eye on mine but unfortunately it still looks like it's dying as there is more browning of the fir. Although the really weirdest thing is the top/tip of the tree is totally lush green!? Odd. I shall keep clearing the dead away but I have a horrid feeling it won't end until I just have a  baldy stalk left in a really nice pot 😩

Fairygirl

Looking at that 2nd pic, I'd say it was beyond recovery to begin with , regardless of anything you do. 
They don't cope well if allowed to dry out, and in pots, a specimen of that size and maturity needs a lot of attention. To be honest, it looked a bit dehydrated in the initial photo. If it's been in sun and wind, that dehydrates it very quickly.
A soil based medium is vital, not compost, as already said. It doesn't have enough heft to support a mature shrub or tree for any length of time. Feeding is also pointless, and can be counter productive, as a stressed plant can't cope with food as well.
 
Firs of all kinds can certainly  fall prey to Phytophthora. 
Here's a link
https://www.forestresearch.gov.uk/tools-and-resources/fthr/pest-and-disease-resources/phythopthora-austrocedri/
However, many firs/conifers etc have also suffered in recent years simply due to drought in the UK. Many areas have had severe problems with a lack of consistent rainfall, and although established trees can cope with regular shortages of water, they can still succumb if there are frequent spells of severe drought.