Posted: 02/10/2014 at 09:12
Hi Tingly - as others have said the answer depends on the plant. It also depends on the size of the root left.
I have found that ash tends to sucker so I would think you have a risk of regrowth if there are large ash roots left & I think that most bamboos will regrow from small pieces of root. The other plants you mention are less likely to be a problem.
I suggest you look at some of the sprays for killing tree stumps if you think the ash roots are large enough to warrant it. Failing that - dig out what you can when you can & glyphosphate when you see any green growth.
With the bamboo take out every bit of root you see & glyphosphate every bit of green growth. If this was one of the spreading ones it can be a bit of a battle (but winnable!) to eradicate it.
It might be sensible to not replant the area until you're sure there is no regrowth (ie into early summer) - trying to spot & glyphosphate tiny bamboo shoots amongst new planting could be more trouble than it's worth - depends what you plan to do with the area. I had one year when I spent all spring just zapping regrowth & digging out small bits of bamboo root. I grew a load of expendable annuals to plant for summer colour then in autumn I was able to replant properly.