Have nematodes killed my plants?

Edlf

I used vine weevil nematodes and slug nematodes this year on some container plants in my London garden. First my (dwarf) wisteria died as it was coming into bud. Then my viburnum died as it was coming into leaf. And my Rhododendron looks very sickly with soggy flowers that have shrivelled before opening. I’ve done nothing different this year apart from Nematodes. Could this be the reason? All thoughts gratefully received. Emma 

Lyn

I’ve used both, never lost anything.
If you put photos  of your sickly plants on here, maybe we can identify the problem. 

Singing Gardener

More likely to be the temperature extremes we've had I should think. Nematodes are unlikely to cause a problem.

Edlf

The Dead wisteria and dead viburnum have both been disposed of but here’s a photo of my soggy sickly rhoddy flowers. They are normally pale pink and glorious..

NewBoy2

Not slug nematodes.

Fairygirl

Nope. That's weather. 
Most likely- too dry at the time of buds forming.
Common problem this year - lack of water last summer. 

Edlf

Oh. My. Goodness.  Well that's one mystery solved!  Thanks so much.  

Edlf

I’ve just found out another possible cause for the Rhododendron flowers turning brown and soggy could be Petal Blight. It is a fungus that lays dormant until the conditions are right, those conditions being too much moisture such as torrential rain (as we had earlier this year) when the buds are getting into their active growing phase. This causes the opening flowers to suddenly become faded and soggy, eventually turning tan/brown. All the flowers have to be picked off and the top inch of mulch removed and replaced. Sharing this in case others have the same problem. It’s heartbreaking seeing the poor bees trying to get pollen from the useless blooms :-(

Fairygirl

There are indeed other problems with flowers not performing, but you said the blooms were shrivelled before opening. 
I think its more likely the lack of water last year. None of them would ever flower here if it was some excess rain in February 

You haven't shown photos of the Viburnum and Wisteria though. There could be other factors affecting your plants, but it's difficult without good  photos - close up and the full plant. 

Edlf

Hi Fairygirl - I’m afraid I disposed of the viburnum Kilimanjaro and wisteria (both in containers) so I can’t take photos of them. But what happened took place very suddenly, within 24-48 hours. The plants were just coming into leaf, looking fresh and healthy. Then within a day or 2 all the leaves on both plants turned brown and dry. They shrivelled up and dropped off. The plants then completely died. (Incidentally I have another viburnum Kilimanjaro in a container and it is fine. It’s doing really well. It was situated next to the dead one either side of the front door. So I’m utterly mystified. )
Regarding the Rhododendron with flower problems; whatever is wrong with it, I think it’s different to the wisteria and viburnum. The main plant is still alive. Here’s another hopefully better photo of the flowers. They feel wet and soggy. They started to open (I got very excited - it’s normally a fabulous display)  then they stopped opening, started turning yellowish and went limp and soggy. 

Fairygirl

I'd say it's weather then - with the rhodo. Often - rough weather just when flowers open means they get annihilated, and the pale ones often suffer more readily, so it could be that, as opposed to lack of water the previous year. Camellias are the same - I had a pale one in a previous garden, and I rarely got to enjoy the flowers because the weather was always dire at that time. 

With your two in pots at the door - it's surprising how one can get more wind/rain etc even though we think they're in identical spots. The one getting the brunt of the prevailing wind will always suffer more. 
Another possibility is animal urine. If you have cats appearing in your garden, that's a common problem - often reported on the forum. 
I don't grow Wisteria, but again - it could be the same problem there.