Have used roundup twice this year but its seems to have made the weeds get stronger and bigger, areas that I have planted I have used plantex but weeds are coming through it. Any suggestions?
You seem to be looking for short cuts and quick-fix solutions … there are none!
To get a 3/4 acre site orgainzed takes considerable effort in the early years. Get the whole area levelled and cultivated properly.
You need to decide what each area is to be used for. Designate areas for tree planting, and plant those in autumn. Also sow grass seed for lawn areas. Mark out flower beds and borders.
Do not plant any area of shrubs or perennial flowers unless it is free of perennial weeds, such as dandelions or docks. Then hoe the areas between plants regularly to keep them weed-free and when the plants meet, they will shade out weeds.