soil mix for large outdoor planters
I am going to plant my very large planters, some 32" wide and tall, and some 36". Some are wooden with no bottoms, others are glazed ceramic. What would be an appropriate soil mix? Some will be placed on a rocky hillside, with morning shade and dappled sunlight in the afternoons. Those I will plant with rhodos, azaleas, and a Japanese Maple. I may put an ivy in one corner of the biggest planter, hoping it will grow over an adjacent arbor. I had thought about just using garden topsoil and peat moss/manure mix, but turns out that was very wrong, according to the garden centre! So, does anyone have a favorite bagged mix that I can buy up here on Vancouver Island? I went to the garden centre today and found that the cost of outdoor planter mix was $6.99 for 20 litres. I would need masses of bags, and doesn't that seem like a lot of money? Also, do I have to fill the entire planters, or can I use broken styro in the bottoms to take up some space?