Antirrhinum lurgy

I have some of last year's antirrhinums that have come back after taking a pounding in the winter. They are flowering but the leaves on all of them are mottled yellow and green and they have not been as vigorous as i'd expected. I wanted to let them set seed and self-sow.

Should I let them get on with it or pull them out now? I have some new small snapdragons that I want to plant out. Are they likely to also succumb? Should I avoid the places where the old ones are planted?