I am stumped on what kind of tree to plat at a house where I am putting in a patio. The tree can't be any larger than 15' in dia. or 20' tall. The tree has to tolerate very moist soil. The area isn't drenched 24/7 but it remains moist most of the time. The tree will also only get part sun and part shade about 50/50 because it is in a corner between the house and the deck which are both 2 stories tall. I live in zone 5. I know my plant material pretty well but im just stumped on this one. Thankyou in advance for any help.