Kind of expensive, but check out Raintree nursery.

The Missouri Department of Conservation is the cheapest place to by Pawpaw and Persimmon trees. They keep going in and out of stock, as they dig and ship more, so you have to jump on them when they put them back into inventory. If you get 100, they come out to less than $1.00 each with shipping.

https://mdc12.mdc.mo.gov/Applications/TreeSeedling/?page=4

I have 1000 trees coming from them this year, 300 pawpaws, 300 black walnuts, 100 tulip poplar, 100 black chokeberry, 100 American hazelnut and 100 bald cypress.

Keith

The MDC East Mo HQ Office is located at Busch Wildlife Area, for catalog call 636-441-4554, But may be too late to place orders for this year. Only a small surcharge for out of state orders.

I'd like to try paw paw again even through all 3 failed. I'm just not sure where to buy for my zone 4.

Check Michigan sources