New shoots wilting on my Black Hamburg

[marcopolo]

Hello all, i'm in need of some urgent help or advice. About 6 days ago the shoots on my 8 year old Black Hamburg vine started to wilt. I have no idea why but I can go through the steps taken prior to that that may have caused it.
At the start of spring I mulched the area outside the greenhouse where the roots are (it's fed in through a hole in the bottom of the greenhouse) I was pouring in about 8litres of water once a week to get the nutrient down into the roots. Also it had rained once. Now for weeks and weeks there was no problem. All of a sudden the wilt happened. Also it had rained once heavily through the night a few days before the wilt occured.

Also another thing i'd done was wash the new brick wall just adjacent to the root area with a brush and hose (again can't have been more than a few litres.)

I'm worried there's maybe chemical or something that has leeched down and is killing the plant.

My instinct is to soak the ground with water from my water butt to wash away any harmful things but I have held off because it could just be it's overwatered and that would make it worse.
I have scraped the mulch off for just now.

I don't believe it's anything to do with the cold as the last few weeks have actually been warmer and the vine shoots had started growing vigorously.

HELP!!!! what should I do? Picture attached. Many thanks in advance.

 

[Rice_Guy]

* the chemical (family) I would be concerned about is 2-4D, unlikely to exist in a detergent
* you are correct over watering can kill the roots, unless you have a lot of clay it should drain before hurting the plant
* you mention cold, in Wisconsin we had night time at 26 with some frost damage last week, this should recover though
* greenhouse, , , are your automatic vents working?
* your color is still good, I would wait and hope at this point, farming is a risky venture

 

[marcopolo]

Thankyou for the reply.

Weed killer was applied about 6-8months ago in the close proximity, but not on top of, very careful to spray locally. Roundup, not 2-4D.This was because of Lilac shoots coming up too close to the area. However I never saw the vine react at all then.

It is Very clay soil I have, very heavy.

All auto vents working well and a doors either end of the greenhouse open to let air blow through. Heat is not too excessive. I have a heater to keep temps above 40F (5C) in the greenhouse as I have tenders growing in there also.

 

[marcopolo]

I wee update, over the last few days, regardless of no rain it has continued to wither and deteriorate. I dug a test hole a wee way away and the ground all the way down is very dry so it appears my ground drains well. I think i've got to go on the assumption something nasty went down into the soil.

So in desperation what i've done is put a small amount of liquid camellia/rhododendron feed into 10 litres and watered (as they prefer slightly acidic soil) It did appear to perk up a very small amount after a day and a half...but it could be me perceiving that....