Plant growing like wildfire - what is it?

[LittleRedYoshi]

Hello wise Mumsnetters - hoping you can identify a plant for me, please...

Bought a house in mid April, no sign of said plant at that time. But in the 10 weeks or so since then, it's completely taken over - growing over the other plants in the flower bed - and having just pulled it all up, it's filled 2 black sacks. It's weirdly stringy, so has stayed low to the ground, except where it's found fences and obelisks and has happily climbed those. It has what looks like little yellow buds, but I haven't actually seen any flowers. Photos (hopefully) attached.

What is it and how do we keep it under control?

It’s chickweed and pulls up easily.

Wow - that was a fast response! Thank you!

I'm not sure but I think those look more like seed heads than buds.
You'll almost certainly find more springing up - hoeing is a good way of dealing with weeds when they're at the seedling stage.

Yes, those are developing seed capsules. It’s in the same family as pinks, carnations and Lychnis coronaria

Oh dear, seems like this is going to be a problem for a while then! We wouldn't have let it spread to the extent it did if we'd known. Will keep a close eye out and deal with any more as quickly as we can.

Ah don't worry just pull most of it up then use a quick burst of Roundup on the stalks. It'll be gone within a few weeks.