Could you advise the easiest way to kill grass to make way for new raised beds for vegetable growing. do not want to use roundup etc. and hubby would prefer not to dig out old lawn. Would cardboard or mulching work and how long would that take? Or could the new topsoil/manure be just put straight in on top of the grass inside the raised beds?
Killing the grass with Roundup is a possibility .. this chemical being very safe.
Mulching is also a possibility, but this takes a few weeks or months dpending on the nature of the weeds. For instance, dandelion is very persistent.
Placing new top-soil and/or manure on top of the grass might work but weeds such as dandelions and docks might come through if they are vigorous and the layer of soil is not deep.
Note; raised beds are not essential and very good crops can be raised ‘on the flat’. The beds do confer some advantages in terms of earlier sowing and deeper soil.
In summary, use a single high-level application of Round-up as a once-off measure, or place old carpet or similar over the ground to kill all weeds. If you want to get going this spring, the mulch might be a bit slow .. depends on the weeds.