How large can thistles grow?

I know there are gardeners who would regard the giant cotton thistle, Onopordum acanthium, as a weed, but I love it and carefully dig up the seedlings wherever they pop up in clusters, and then redistribute them for better effect in our borders. read more

The word “thistle” is a blanket term that refers to a whole bunch of species. The largest in my garden are cynara cardunculus (commonly known as “cardoons” in the UK.) I’m 6′ tall, and they are a fair bit taller than me. read more

John Lowde, 86, believes the prickly plant, which is taking up most of his front garden, could be the tallest thistle known to man. He has grown the common garden weed before, usually only reaching a modest height of 4ft, but this grey scotch thistle is his new pride and joy. read more

The dwarf thistle, Cirsium acaule, is the one with an incredibly spiny rosette, which pricks your behind when you sit on the grass. Wherever they spike you, thistles hurt, and of course it's even more of a pain if you do find your garden filled with them. read more