Help with our dogwood...

Hello friends. New here. Can you help me?

I received a cornus from family which I subsequently planted in our rockery. I watered it diligently and it was pot bound when I planted it, but all the time I had it, it's been developing black stems (from end downwards) and now its leaves are turning white...can you help?

 

Here's another pic

 

Not sure but a couple of things.....pot bound isnt great. No matter how much you water it a pot bound plant will dry out and struggle. I would dig it up, loosen roots and soak rootball in a bucket of water for half an hour or so. I would prune all those woody stems back to ground level.
The white leaves? Sounds like mildew. Hopefully, replanting as above will help with the mildew too

 

Thank you.This is all consistent with the black stems and yellowing leaves then? It's a bit scary cutting back right now, but will go with it...Many thanks.Soil is alkaline by the way...if that matters.

 

Not chlorosis then?

 

What variety of dogwood do you have Sarah?

Ah Sarah, You said leaves are turning white originally but now looking at pictures they dont really look white, do,they?. Chlorosis then could well be avproblem so I would spray with epsom salts.....works fast. Incidentally, I sprayed a few plants with epsom salts today and will repeat again in a few days.
If roots were pot bound the plant would struggle to take up nutrients.
Spray a couple of times ...let us know if there is a change.

 

It's a winter flame variety. Should I dig it up and soak the root ball too/tease out roots?

 

I'll say that again...Midwinter Fire..close

 

Midwinter Fire can be fickle in my experience Sarah...
It all makes some sense to me now.
Right, if mine, I would dig it up, loosen any congested roots and then soak for 30 minutes. Replant, cut the woody stems back and water it well. Dont water every day.....in a few days water it well again, mulch and give it a spray of epsom salts. Give it a chance then to grow and water once a week or so during hot, dry weather.
I have to say most of the other coloured stemmed dogwoods are easier and more robust

 

Many thanks. I have now dug it up and got some of the roots out. It's now soaking in a bucket. Assuming ordinary multipurpose compost will be ok for it. I shall spray with Epsom. A table spoon to a gallon, I read elsewhere - would that be the thing?

 

@Verdun could you expand on that please?

 

Very instructive! Thats the reason this forum is so friendly and informative!

 

I grow it but it is quite tender/weak I think? The latest growth prior to winter on mine is always blackened come Spring and needs to be pruned off. @Sarah Eley you don't say what part of the world you live in? I was told the reason this variety can be a bit "fickle" as verdun puts it (correctly in my experience) is that it has been so highly engineered by the plant breeders, they have weakened it in the process. Bit like variegated plants not being as strong a grower as pure green. A a virus introduced and B can't obviously photosynthesise as well. I grow mine in a pretty sheltered spot (admittedly in Scotland!). It sulked for ages post being planted but has now got it's act together and grows reasonably well but nothing like as strongly as my other red, yellow and green stemmed Dogwoods.

 

Yep - it's not in a pot. It's in the ground.