This is my third summer of gardening. I live in the northern part of Ohio, on Lake Erie, so our winters tend to be cold and snowy. The first year nothing grew in the garden. Every single plant stayed the exact same size as when I bought it from the nursery. The second year we put down horse manure and tilled it in real good. This made all the difference - everything grew! The soil is of very poor quality, no top soil and very hard, much clay and many rocks. I'm wondering if there is anything I need/can do to prepare the soil this winter. Does it make a difference, spreading manure in the fall versus the spring? If I till everything this fall will I need to do it again in the spring? Any suggestions? Thanks.