Posted: 16/08/2015 at 18:41
I too have a garden that backs on to fields and get all sorts of weeds coming through. I don't mind clover and speedwell as they are pretty and green but big leaved stuff like plantains and dandelions are a bit obvious.
You could use glyphosate as a spot weed killer on big stuff like dandelions but otherwise wait till autumn and apply the appropriate weed and feed mixture, following instructions on the pack.
You can also aerate the lawn by going over it with a large garden fork, piercing the lawn to a depth of several inches and wiggling it about to enlarge the holes. Then you scatter lawn sand and brush it in. This will improve the health of the grass roots and let them grow stronger.
Lastly, raise the level of the blades. Healthy grass needs enough leaf to feed strong roots and fight off weeds and that lawn looks scalped.