Hi Tricia, absolutely no need for cardboard because the oly reason for using it is to prevent large, established weeds growing up through the soil and compost of beds and pathways too.
I am using a lot of cardboard in my new garden, for the first year only I hope, where there are oceans of buttercup, dandelion, couch grass, cow parsley, celandine etc. But you do not have that so just carry on as usual, only difference is no digging and adding any organic matter to the surface rather than incorporating it.