I put in two raised planting beds (4'x 4' by I think 12 inches high. I put down that weed preventer cloth (can't recall what its called) then did a soiless mix like I do for my house plants. equal parts peat moss, perlite and vermiculite. Boy did it cost plenty for the bags of stuff at a lumber yard out here (Menard's) the cheapest was the big bale of peat moss. Plus no mixing bowl,
it was a lot harder trying to mix them all up- what a nightmare. Anyway I just got it for fancy hostas and they loved it. Also cats love to make it their litterbox. I DO NOT HAVE CATS. But everyone and his brother does and lets them free range all day. Plus squirrels keep digging up stuff between the plants and I have to put a rock over their hole(s) . Sometimes moth balls help. In dry weather I put down black pepper or cayenne, till the wind blows it away.
I was hoping I could build cages around them with hardware cloth and also for a top. But, I wouldn't be able to easily get to them and they wouldn't be able to spread naturally. So I just frustrate myself.
Wanted to order a nice soil mix but, the nursery charges like $ 70. to bring it two miles to my house. Plus you have to buy a truckload or more - so no go for that. Later I discovered Home Depot will order large bags of soil amendments perlite, etc. - no shipping charge if you pick up at the store. Not much fit in the back of a Toyota but, what else is new??