Birdsonghill
Crowing
It does seem to do better with compost mixed with partially decomposed old straw. The potatoes do well in my potting mix of peat, perlite, compost, vermiculite, azomite and with ground limestone to adjust ph. I am generous with the compost with either choice. Using the potting mix, that is not a cheap way to grow potatoes with all the admendments purchased plus the cost of the grow bags that must be replaced every 4 to 6 years used outside. So, I favor the compost and old straw mix. Attention must be made individually with each bag to maintain plenty of moisture without waterlogging or encouraging molds or disease. Too much is maybe worse than too little but you get the idea. The compost several inches deep with a bit of old straw then the seed potatoes, more straw then compost and so on. More straw than compost as the layers add up and watering in the compost incorporates well enough.Do you get a better result, with 100% pure compost without other things in there? Or is it better to mix it with other things?