You can water the pots with nematodes when the weather warms up so don't lose sleep!

Probably, but do as Steragram suggests. Do not use Provado Vine Weevil Killer on Pelargoniums, it kills them as well as the grubs.

Gosh I didn't know that!!

Says so on the packaging!

Why not use Armillotox as a prophylactic treatment. Your green house will pong of gas tar for a while and it treats moss and algae on paths too. It is a natural product that cannot be advertised as a pesticide due to some daft EU rules.

Test it out on an unwanted plant first though. I find Pelargoniums do not like a lot of chemicals.

I lost some of my heucheras to the horrors, the grubs ate the roots, some are ok and one....stoplight....was only halfeaten so I scrubbed the roots under running water..........its still alive....just!

Meant to say conservatory. So nematodes best in an enclosed space. Looks a bit expensive too. Hate using Provado but needs must. Pamg I have had that trouble too. My Stoplight Heuchera was nearly eaten away. I rescued it just in time, and its coming on quite nicely now. I still intend to try Armillotox on the on some potted up sprigs of Heuchera rather than on some of the huge mature ones I have. If they survive well. I shall use it on the big ones.

Oh dear Owdboggy, it would be such a help if I could read.

Thank you all, I did think about Provado, (got a bottle full in the shed) but something stopped me, good job I did cos I feel sure I would not have read the label !
I took the sensible course and asked advice from you wise ones.
Nematodes already on order.
Once again thank you.