hi

picture the scene, i have a front garden comprising rectangular lawn surrounded by 4 x borders, within which i've planted various (mainly everygreen) shrubs. within the centre of the lawn there is a circular area of soil with no plants/shurbs in it.

the borders and circular area suffer badly from what i think is 'sheeps sorrel' and, after reading online and being advised on here, i now realise the best way to tackle this weed isn't to turn the soil and pick out what you can but rather to use a suitable weedkiller on the leaves without disturbing the soil, right?

i tried this approach towards the end of last summer in the circular area (really good dose of weedkiller, haven't turned the soil since) and whilst i can see a few bits of the weed reappear it's nothing to worry about. the easy thing about the circular area was no plants/shrubs to worry about, i only had to ensure the grass surrounding the soil wasn't touched by the spray.

my challenge with the borders is all the shrubs, i need to protect them and the grass. someone advised i brush the weedkiller on by hand but i'd rather spray. based on this will the following work and, most importantly, will my shrubs survive?

1. cover all shrubs in plastic sheet tied at base i.e. all leaves protected.
2. cover edge of lawn with plastic sheet.
3. this leaves me to liberally spray all exposed areas of soil in the borders.

my hope is the weedkiller will be absorbed by the leaves of the weed and kill the weed by killing the root system ... however if the roots of the weed are entwined with my shrub roots is there a risk my shrubs will be affected, or will they be okay due to their leaves being covered during spraying?

bear in mind i'm intending to give the soil quite a good dose to try and eliminate what is quite an unsightly weed which spreads like mad!