The first step for existing garden soil improvement. Is to determine what it needs. Soil texture often needs improvements to correct drainage problems which usually are easy to detect, such as, heavy clay soils retain moisture, or sandy soils drain to quickly! But to detect nutrient deficiency, you should test the soil. Garden centers and nurseries offer a full range of tests for a variety of nutrients as well as determining acidity.
You can also provide a soil sample to your local county agency for testing. They will give you a comprehensive analysis for a small fee of course. But this is not necessary if you follow these easy steps every year to replenish soil nutrients.

Step By Step Blueprint
To Start And Maintain A Home Organic Garden.

In general, organic additives are the remains of plants and animals. The organics you apply to the soil are most often in the form of bird and animal manures, plant (green) manures, cover crops, compost, sea products. Many gardeners prefer to have a compost pile where they dump weeds, fallen autumn leaves, and grass clippings, and allow them to decompose into humus. Often organics are first put on as a mulch--that is, a surface layer. Some decomposition occurs during the growing season, and then the residues are mixed into the soil. This Improves Texture, Condition, and Structure of soil, providing better aeration and temperatures of the soil. Which provide for healthy roots and the ability for strong growth.
But for your basic garden needs. plant greens, leaves, and the cut off greens from the vegetables you eat, are more than enough to replenish your basic Garden.

Compost improves soil structure. If your soil is hard and compacted, sandy, heavy, stony, or wet, adding compost will improve its texture, water-holding capacity, and fertility. Your soil will gradually become fluffy and brown-the ideal home for healthy plants.

COMPOST PILE ADDITIVES: Practically anything that was once alive can be added, including garbage from the kitchen such as non-meat table scraps, egg cartons, paper towels, eggshells, coffee grounds, shredded paper from the office, etc.

Soil Drainage Improvement
COMMON SOIL AMENDMENTS:

Compost: A Dark, rich, crumbly organic material with a course texture. Nutrients depend on what materials were composed. improves soil texture.

Builder's sand: Coarse, natural sand with grains somewhat larger than beach sand. Improves drainage and helps loosen soil, But do not use on clay soils.

Peat Moss: A lightweight and inexpensive natural amendment. Helps loosen heavy soils and improves ability to hold moisture.

Composted Manure: Rich, dark texture, easy to work into soil. Rich in nitrogen, improves drainage and moisture retention in the soil.

Limestone: A Natural, chalky white powder left over from mining procedures. Dolomitic lime contains calcium and magnesium and helps lower soil acidity.

Ground wood: Ranges from the ground bark of trees to processed wood chippings. Improves soil texture making it more airy, aids in soil drainage.

Leaf Mold: Mixture of composted leaves and grass. High in nitrogen and potassium. Nutrients are slowly released into soil.

Farmer's also use Cover cropto help improve soil.
Millet for soil improvement.
Growing Cowpea for soil improvement.

To Start And Maintain A Home Organic Garden.

Refresh Your Lifestyle
With Organic Gardening.

The best time to start is in the fall after the foliage settles, and the flowers are finished. I like to take the grass and leaves from the last grass cutting and cover the flower beds with a heavy covering of grass and leaves and let them decompose through the winter. This allows the nutrients to slowly enter the soil without washing away! Depending on your climate conditions, I live in northeast United States. Then in the spring I remove the top layer of dry leaves and grass, which has left a wet layer of grass and leaves that I mix into the soil. I try to do this 1 to 2 weeks before planting spring flowers or vegetables. ( I just completed this past weekend!)Then I cover with a fresh layer of wood mulch. I prefer the triple ground wood mulch mixed with some top soil this provide more nutrients for the soil, and allows soil to hold proper moisture content for longer period of time! Next week we can do some planting!

Natural Fertilizers

Nature's materials provide the best solutions for soil or plants in need of help! Some products labeled natural are actually highly processed. Organic or natural organic are terms used for fertilizers, which are as close to natural state as possible. Check the labels on your packaged natural fertilizers. If the ingredients are manure, feathers and other natural products they are probably close to natural state. Natural fertilizers feed your plants more slowly and evenly; they increase the soil's ability to retain water and nutrients. The Nitrogen is often a slow release form, which becomes available to plants gradually over time. Fish emulsion, helps flowers and vegetable plants produce more blooms and increase yields.

When?

The best time is to apply to Beds and borders in the spring before planting.

This will give flowers and vegetables a good start and will also improve drainage. When planting new plants dig a hole a few inches deeper than normal. Apply a layer of fertilizer to bottom then cover with a layer of soil, place the plant in the hole. Sprinkle some fertilizer around the roots then fill with soil. Apply composted materials to top to act as mulch. Water well and apply natural fertilizers in liquid form around plant periodically to keep nutrients plentiful.

Grass Clippings can provide continuous food for nitrogen loving plants. Apply a thin layer around trees, shrubs, and plants. A thick layer can prevent water and nutrients from getting to plant.

Types of Natural Fertilizers:

Bone Meal: High in phosphorus: encourages root growth and raises ph. Great for spring flowering shrubs and bulbs.

Blood Meal: High nitrogen also has potassium and phosphorus. Good for ground covers and annuals.

Fish Meal: High in Nitrogen and phosphoric acid. Apply to lawns and good for rose bush.

Feather Meal: Good source of slow release nitrogen. Apply to roses and shrubs in early fall.

Composted Poultry Manure: High in nitrogen, excellent for vegetable and annual flower beds.

Composted Cow Manure: Improves texture and drainage, and adds nutrients.

Kelp: Dried seaweed is high in phosphorous and nitrogen. Good for Roses, and shrubs.