Mystery Invader

[FrankUnderwood]

Can anyone tell me whether this plant is friend or foe?
It's slowly filling an otherwise empty flowerbed and I'm curious. Shall I kill it or feed it?

I'm guessing Ajuga. Very pretty (bee-loving) flowers. Can be quite rampant but if it's an empty bed then it's a lovely weed!

how high does it grow? Looks like the lysimachia that's starting to show through in our garden but that eventually gets to around 1.5 feet and has yellow flowers on

here's ours, starts off as tight, small rosettes and gradually gets taller

Hmm, I'm not sure how tall it grows, as I've only been in the house since October. I've emptied the bed but not planted it yet, and this chap appeared.

Gatekeeper, tight small rosettes is exactly right, and there are similar upright woody stems around it too.

Looks like both the above seem to flower in May-June time, so I'll give it a chance!

or is it mint?

Yep, looks like the yellow flowering Creeping Jenny that blooms in June.
It is a ground covering plant but will climb up plant stems that are in its way. It is quick growing but easily pulled up and dumped as does root as it creeps.

Lysmachia.We have it and just pull it up when it spreads too far.

Definitely Lysmachia, thank you for all your help!
It's a persistant little thing, and has had a growth spurt in the week or so - I think it's days are numbered chez Frank!