I plant very close and always have done in fact I haven't any room left although I can always put one more plant in somewhere !! I planted a fennel today and am hoping it will grow through all the plants surrounding it, just go with the flow and enjoy, if it's wrong, move it !!

I agree. The closer you plant the less room there is for weeds.
You should make sure you feed the plants aswell because when there are lots of them together they will use up the nutrients in the soil .
I grow lots of annuals in plugs so that I have plenty of things to push into any gaps I find. And as Grandmage has said if it's wrong you can move it :o)