If you are talking about rumex, I have one. It has not been a problem so far. I was worried about it at first but was told to control it just cut off the flowering heads so it does not seed. So far mine has not sprung up seedheads yet.
Beerhog

Yes it is Rumex. Cutting off flowering heads make sense. Thanks for sharing experience.

Opal

Red Veined Dock is a nice interesting plant. I live in Shreveport and grew it from seed. It has wintered well and seems to do better with above average water and for a colored leaf plant it seems to enjoy moderate shade.

Best wishes

I'm growing them from seed also. They are just putting on their first true leaf and I already see the red veins!

Thanks for suggestion of moderate shade. Seems many full sun plants actually do better with some protection from late afternoon sun here. But then, so do I :~)

I grew it for a couple of years...blood sorrel, I think it was called, because of the prominent red veins. It will get floppy and wilt fast if it is in full sun and doesn't get watered every couple of days. Mine got huge in full sun but I couldn't get around to watering it as often as it required, and I'd find it wilted, with its foliage splayed out in all directions. I moved it to a shadier location. It didn't take to the move very well and even loads of watering wouldn't revive it. I cut it down to the ground, thinking it'd probably never revive, but decided I'd give it a go anyway. It lived...sprouted new foliage very quickly and needed less water in its new, shadier location. In my experience, it wasn't a spreader...it got very bushy and tall, but didn't grow out of bounds. The only time it gets floppy is when it isn't getting enough water. So at least it "tells" you when it's thirsty ; )
It's a very striking plant. You can eat it, as you would lettuce, in a salad, but it doesn't taste very good. It's bitter. That's according to my mother - I wasn't about to taste it. Pretty to look at, but I have no desire to put it in a bowl with salad oil and croutons.

Renee

I love sorrel. Very edible and delicious plant. For some reason not many people know about it, maybe because it is a French herb.

It is like a mildly sour spinach. I always just pick it and eat it, I don't make salads with it, or soups. It comes up very early from under the snow, and lasts all the way through late fall. I am looking to plant more/or different varieties, because two of my sorrel bushes get eaten to the ground by my family faster than they can regrow.