Cut the bottom off a plastic pot to contain invasive plants & bury in the ground. I have been doing this for a few years & works great for containing plants that tend to spread, but that I still want to plant in the garden. This also works good for planting a plant in an area that tends to get filled with roots etc. from other plants. I will use a larger pot so that the plant can spread it's roots and grow deeper roots, but keeps other tree roots from choking out the one I planted.
How to grow a pineapple. It takes YEARS for the thing to even flower, and then another six or so months for the pineapple to grow to maturity. I can understand doing this with garlic, scallions, and other things that grow quickly and you use often. But this, you're not even getting a return on your investment because it takes so long. Just buy the stupid pineapple on sale.