I recommend planting directly in the ground when you start your gardening journey. I make this recommendation because it's free, if you decide you hate gardening at least you didn't shell out a ton of money. The worst that'll happen is you spent some money on potting soil and seeds.

Let's say you've tried planting in the ground, you either hate it or love it, and you're ready to get some raised beds. Let's also say you need six raised beds for your gardening needs. You look around in-stores and online, the cheapest raised bed you can find is a 2'x2' kit at Home Depot that sells for $49.97. Six of those will cost you almost $300 without the dirt.

You could get a $4 piece of 2x4 lumber and turn it into a 2'x2' raised bed, six of those would cost you almost $25. It won't look as nice but it won't break the bank.

What if I told you there's a third more nefarious way? A way that allows you to upcycle and not give money to corporate overlords? Save the planet and not do a capitalism, try this:

Pallets

Pallets are the wooden things that shipping companies put commodities on while the goods are in-transit. The store gets a pallet of junk, the take the junk off the pallet, and then the shipping company takes the pallet the next time they visit. Sometimes the pallets are too beat up to take back, and the store is stuck with the pallet. Usually the store will throw the pallet out, but you can go and get that pallet(s) if you're quick enough.

Most pallets are made from wood that is chemically treated, except for the ones that are heat treated. If you make raised beds out of pallet wood that is chemically treated, those chemicals will leak into your soil and your plants will be poisoned.

Here's the battle plan:

1. Call local stores and ask if they have pallets they need to get rid of
2. Go to the stores and check if the pallets have HT stamped on them
3. Take the HT stamped pallets home and take them apart
4. Use the pieces to make raised beds, you might need to be creative with your wood

Taking apart the pallets

This is the most frustrating part of the process. These things are built strong to carry as much junk as possible. You will want a reciprocating saw with a "nail-embedded wood" blade. Put the blade between two pieces of wood on the pallet and cut through those nails. Some pieces of wood might still have nails sticking out them, harness your inner unga bunga and smash those nails out with a hammer.

The fun part

Now you have pieces of wood that you paid nothing for, and can assemble your raised beds however you like. You can build raised beds in the shape of squares, rectangles, triangles, fuck it maybe even hexagons.