A couple placement questions: kiwi, pawpaw

I have ordered a bunch of trees and perennial bushes and shrubs, now I just need to figure out where to plant them all. I may have been better off waiting a year so I would know my land a bit better, but I want to get these things in right away since I know they'll take a few years to start bearing fruit.

Anyway, I'm getting three kiwi plants, two female and one male. My understanding is these like a relatively sheltered spot, and that they can grow big and need to be trellised. Our back deck has southern exposure and is sheltered, so could be perfect, except the septic tank is under the deck and the leach field is about 5-10 feet away from where the kiwis would be planted. I've read that they have very shallow roots though, so would they be okay here? Is it safe (as far as us eating the fruit) to be so close to the field?

Also, pawpaws like some shade when they're young right? I was thinking I'd just place them in the middle or near the north end of the food forest so the other trees would provide some shade. Is that good enough shade for them? I don't plan to put the trees too close together as I want some sun to be able to reach in between the trees for crops I put there.

Hi,
I'm gardening in the uk, europe, so cool temperate climate.  I found direct sun a bit harsh for kiwi plants and expeienced scorching on the leaves in our equivilant of a heat wave (26 degrees) so your shady spot sounds ideal - they are climbers in a humid forest naturally.  regarding the leach field, could you plant a screen of nutrient hungry plants like comfrey that will discourage the kiwi roots spreading that way, absorb the nutrient and turn it into something you can then use tp feed the kiwi etc Cannot comment on the pawpaw as dont have the climate - where abouts are you?
regards,
gary finch

kiwis are very vigerous and may be too much for your deck, siding and roof. unless you enjoy pruning. plant with trellis or non fruiting tree to climb. have a trellis running away from the deck to direct them should work

pawpaws need some shade in the first year or so. once it's 10" tall or so, it can handle  sunlight. plant in your forest garden and give some temporary shade. putting it into "woodlands" type soil is more important than shade.  they are an understory tree and like the fungi/bacteria found in forests rather than those found in grass (yards)

I planted two pawpaws this past year.  One as an understory and one in the open with full sun.  They were both about 18" and the one in the sun got stressed so badly that in desperation I had to move it close to the other one.  It perked up in a few days and I am now waiting to see if it survived the winter.