Euphorbia - probably a weedy one that should be pulled up (but watch out for the sap which can cause skin irritation)

Thanks Andrew

I agree with the Euphorbia name, but I think it looks quite decorative.

Decorative yes but it seeds all over the garden an does nothing useful... REmove!

I see this one growing in a garden a few doors down from me - I think it's a weed one.

I'd agree - Euphorbia lathyrus, mole plant. Definitely a weed - unless you have moles which it is supposed to deter.(highly unlikely)

I like this plant and to be honest, would just leave the odd one here and there. It's unusual too as one of the few in the huge genus Euphorbia to be biennial. This is the first stage, it branches quite mathematically next year. It's easy to remove the plants you don't need so don't panic and go all guns blazing. If you have a wilder part to the garden, leave a few. Small Hymenopteran wasps such as Ichneumon and Chalcids feed off the flowers and these insects are amongst the gardeners helpers as being parasitoids, their larvae feed internally on the larvae of various caterpillars down to even aphids.

I agree....I like Euphorbias, especially the big ones like Wulfenii....they are great structural plants. I also have E. griffithii, which has red stems like the one in your pic, Andrea.