I'm not sure it's a good idea with Pawpaws. Mine have lots of pups I need to keep clearing out, and if two were planted together I don't think I could keep up. Every year there is a least 6-8 pups. Hard to dig up too. Second pawpaw I planted I took the time to add huge flat rocks into a box shape in the hole around the tree. That tree grew much more quickly, and produced fruit sooner than my other prolific one,

Pam in cinti

I assume your purpose would be cross-pollination? If so, you might accomplish that objective by topworking (grafting) a second variety into the tree after the first tier of laterals is established by the first variety. And if you're buying trees you'd only have to buy one tree, and then probably not pay any more than postage for someone on this forum to send you scion wood from a superior cultivar.

By pups are you talking about seedlings, suckers, or something else?

The talk of lining the hole with rocks makes me think you mean root suckers.

I don't think root suckers would be any worse if there were two in one hole.

Grafting pawpaws can be challenging so I would not suggest that unless you have grafting experience.

I would suggest putting them about 4' apart. They are somewhat fragile trees and they are less happy being pruned into whatever shape is needed for a very close planting. I never tried any closer than 4' so it may work better than I expect.

Scott

Thanks for the suggestions. Unless I find someone how has good success planting two pawpaws 2 ft or less apart I'll plant mine 6 ft apart. I'm not experienced with topwork grafting but would like to try it at a later date.