Peat moss for Indian Hawthorn in outdoor container?

I need to repot the Indian Hawthorn plant I bought late last summer (this is an outdoor container plant and I'm in zone 9b: SoCal high desert) and was asking a couple of AIs what kind of potting mix and soil amendments I should use. Was surprised that all 3 recommended using a blend containing peat moss (if I recall correctly about 30%). I definitely didn't use peat moss (or coconut coir) when I planted it last year (I believe I used Organic Miracle Grow Potting Mix for outdoor container plants, extra coarse perlite, compost and earthworm castings but don't recall the ratios). So now I'm uncertain about whether I should stick to what I used last year (maybe 60-65% Miracle Grow potting mix, 25% coarse perlite, 10-15% compost & earthworm castings) or use 25-30% peat moss in my potting mix; what do you think?