Hello Rick, if you don’t need the plot this year, you could cover after spreading the new compost.
3 months old is fresh for planting into.
If the soil is now clear of weeds and you want to grow this year, planting is an option, and stack the new load in a heap to decompose, for spreading in autumn or winter.
Rhubarb – I would not try to transplant, easier to cut off some edge roots and plant those to make new ones.
