Q Could you please tell me what this plant is? can't remember if I planted it or not!
Joyce Burnham, via email A That looks like the caper spurge - it's a euphorbia whose seeds resemble capers but are, like the rest of the plant, poisonous.
Euphorbia lathyris is Ialso known as the mole plant as its smell is reputed to deter moles. It's biennial so will set seed this year and then die off.
If you don't want this plant to self seed, get rid of it now.
When doing so, make sure to wear gloves and protect your eyes as the latex in this plant can really burn skin.