Dolomite is like garden lime.
If they don't grow properly then they won't produce peas properly. Your orginal post says they aren't
growing well. it may be because the soil requires sweetening.(Or having the Ph raised) Thus the dolomite. You can add it and chip it into the soil now, though it will take a while to change the soil Ph. If the peas die off, prepare the beds again, this time with dolomite or lime. They like a well cultivated soil and hate
weed competition. I think peas can handle frost. Not sure.