Healthy gardens start from the ground up. While you enjoy beautiful blooms and big vegetables, your plants enjoy lots of rich, organic matter around their roots. Unfortunately, garden soil doesn't always cooperate. Some soil is too sandy, so it can't hold moisture or nutrients. Other soils have too much clay, so water isn't absorbed, and there's no air for root growth. If your garden soil leans one way or the other, you can make a big improvement by adding some organic matter.
Organic matter is material that comes from plants or animals. Leaves, grass clippings, compost, and manure are good examples of organic material. It doesn't contain pesticides, herbicides, or synthetic fertilizer. When you mix it into your soil, it breaks down into what's known as humus. Humus helps your soil hold air and moisture. You might say it softens the soil, to promote easier root growth and better absorption of nutrients.
Any time you plant is a good time to add organic material to your soil.