Rough rule of thumb. Green Oak = no Dead Oak (say at least a year) = OK. Black Walnut = no

This December, a day or 3 before Christmas go to your local Lowes/Menards/Home Depot and talk to the manager in the garden section. Ask him if they will be throwing away any unsold Christmas Trees on Dec 26th. You usually can get all you can carry (and then some) the day after Christmas, but make sure you get there on that day to pick them up. You don't want to burn that bridge.

This is one of 3 loads from three years ago. The trailer is 8' wide x 12' long. I think I was able to fit 100 trees on the trailer per load.

[Linked Image from i.imgur.com]

Get a big spool of paracord and some cinderblocks. 1 block will be enough weight to keep 6 submerged, I used para cord around the trunk and tied to cinderblocks, making many brush piles in the ponds.

You want approximately 20% - 25% of the surface area in the pond in cover for the fish.