What is this plant?

Can anybody help me identify this plant and if it is a weed or not? My dad planted this in lockdown and it has grown ×20 the size but is unsure what it is and if we need to get rid of it .

Thanks

 

I'm not sure which weed it is, but if that was in my garden i certainly wouldn't wait till it goes to seed!
It has a menacing weedy look, (dandielion family?) and I'm sure someone will soon put the right name to it.

 

It does look like horse radish leaves although the one's I've seen usually throw up some feathery fronds too. I guess they might still develop..

 

I think its evening primrose.

 

Welcome Beej118.

It also looks like dock, the picture is rather small to tell properly. Both dock and horseradish both have tap roots and are difficult to remove once they get a hold. If the root is broken and some left in the ground it will re-shoot.