What nitrogen fixer for orangery plants

Hi,

I live in a 7a zone, and I love plants that need to be in 8-11 zones.
I know it's bad, but anyway, it's a pleasure to eat fresh citrus fruits in winter.
As I put them back in the orangery during the autumn, I have to grow them in big pots.
I use organic fertilizer, but would love to get nitrogen fixers in the same container.

I'm looking for crawling plant that would cover the mulched soil. As much as I like climbing peas, my wife won't like it, so crawling or small is good.

Any idea?

Thanks.

Birdsfoot trefoil (Lotus corniculatus)? Or some form of clover?

Both don't get too tall, but can be 'mowed' with a pair of scissors to be kept lower.

Thanks Charli.
I have some red clover seeds, so I will give it a try.
If anyone has an idea for other nitrogen fixer, crawling if possible, let me know.

What about sensitive plant (Mimosa pudica)? It's a small creeping legume, tropical so it's amenable to your treatment of the citrus. And the way the leaves fold up when you touch them is way cool!

I have had this plant in the past, several times indeed.
My kids and myself must have killed them by "overstressing" them.