What is the white dusty stuff for n my alseeet pea?

[Cutandpaste]

And how do I get rid of it please? Will it spread to other plants?

on my sweet pea... am on my phone in the garden!

It looks like mildew, plants get it through lack of water. They need to be watered more frequently and should improve.

Thank you. I've given them a really good water and will keep an eye on them. They're not doing so well to be honest. I'll try tomato feed this weekend as well.