How would I transfer a pine tree from a pot to "in-ground"?

First, where the branches have broken off, make a clean cut.

Next, yes, you may just dig a hole (2–3 times larger than the root ball of your tree) and plant it in the ground. You can just plant it in your soil & hope for the best, but I wouldn’t do that. Here’s a good site for planting rules

What type of soil is it in now? My guess is potting soil. Mix in as much of that soil as you can into your hole along with one bag of top soil. We always add pellet pine fertilizer or break up these spikes into our planting hole, as well.

After planting, water your pine using this watering schedule Personally, we always make certain we water our pines well in late fall, so they don’t over dry in winter. For a new planting, I would be extra cautious for the first winter in the ground.

Good Luck!

Here is an in-depth guide to transplanting trees.

In addition to the good information written above I would select a place in your yard that gets adequate drainage and sun light. You didn’t mention the species of Pine that you have but most pines can handle the sun. Also check for electric wires above the planting spot as well as at least 5 feet of clearance from any ground structure, other tree or bush.

Dig out a hole about 3 times as big as the root ball. Then use the hole a s mixing bowl to mix 2 cubic yards of composted material (Home Depot has it) into the soil in the hole.
Dig out just enough of the soil mixture to accommodate the root ball. Make sure that the tree is planted such that it sits on a little hump (Like a pitchers mound). Do not plant your tree into a depression.

Stake the tree on 3 side to keep it growing straight.

Perhaps most important: Water your tree frequently during the hot Summer months for the first 5 years that it is in the ground. You might consider putting in a drip system on a timer that will give several small waterings a day on the hottest days.

One thing I would ad to all of this- if you live in an area where there are deer, put a wire fence around the tree to keep the deer away until it’s established.

I planted a pine tree that had been my mother’s last Christmas tree on our WA property, doing most of what was suggested above. So far, it’s still going strong!

Thanks for all of the great advice. I’m in NJ in the suburbs so deer and animals aren’t a problem. The yard has decent room for the tree. There is another tree (a very large/old Japanese Maple) in the yard but I’ll space them accordingly.

Dig your hole a larger size than the pot is in, place the tree in it, and fill with a mixture of peat moss and potting soil, and water well for the first two weeks. The looser dirt around the root ball is important because it enables the roots to take hold in the soil. Once they’re established, they will spread out into the surrounding, more compacted soil.