Good soil means healthy plants and if your soil is poor it can take time to build it up.
If your soil is not good, you can give it a boost with an organic fertilizer that has plenty of calcium in it as most veggies need this.
Certain leaves take longer to break down - in this case, I put them into my worm bin and let the worms do the work for me -in spring I empty all the lovely worm castings into my garden.
Building up the organic content in soil takes time if the soil is not good, but I have found that mulching throughout the year so that the soil is always covered is the way to go.