Garden fever

Okay so I have it BAD! I'm planning on two new garden areas for my yard - a shade garden for under my oak tree - and this: an 'herb spiral'. I had seen a website on this a couple of years back, but never had really seriously thought about putting one in, but after looking at the prices of fresh herbs in the grocery store for a little piece of herb ($2.50), I have decided that it is economically sound for me to grow my own herbs that I normally use. So.. here I am, fixing to put in another garden area that my husband will have to mow around. I am rather stuck on trying to figure out how many bags of dirt I should pick up at The Walmart to make this herb spiral, and bricks - how many will be required? The nursery that I go to in town, is getting in their spring plants this coming Friday (woohoo!) and she showed me the list - its quite extensive- and I will be doing quite a bit of shopping there for herbs and the like.

On another note - for once! Walmart has RHUBARB! the plant - I am not exactly sure how it will do in zone 8, but I am going to buy a plant and see how well it does in our summer heat. If I can avoid buying rhubarb at the grocery store, and get it fresh for pie and crumbles, that is the best.