[Wobblymoo]

We have a patch at the side of the house which the builders very kindly <koff> landscaped with plants purely for ground cover, one being periwinkle. I have so far spent 3 days trying to get rid of this and have got rid of the bulk but the plan is to plant potatoes in there this year to break up the soil and then next year turn it into a fruit garden, or technically not a fruit garden as I've just learned rhubarb is a vegetable.
I can't use something like round up on it as there is a hedge on one side and a lawn on the other but if I cover it with black plastic, how long will I have to leave it on to ensure root death.
Denise

[Trillium]

Depends on what strength of roundup you're using (there are several) and how well you sprayed, but on an average, 3-4 weeks should do it. Might take longer but rarely less. And be sure you don't do it on a windy day or more than the periwinkle will die.

[Wobblymoo]

That's what I really don't want to risk, , but would I be able to put potatoes in then straight away?
Denise

[richyrich7]

Yep