Adding organic fertilizer to any garden, whether for vegetables or flowering plants, can improve the quality of health, size and productivity of your plants. When your soil is lacking in nutrients, fertilizer returns essential nutrients to the soil. Whether it's manufactured organic fertilizer or homemade, such as compost or manure, you'll be helping your plants grow naturally without the use of harsh chemicals.
Till the soil of your garden to a depth of 8 to 12 inches to loosen the dirt and break apart clumps. This will give the roots lots of room to spread out.
Apply commercial organic fertilizers over the top of the soil, following the manufacturer's instructions. The quantity of fertilizer needed will be based on the size of your garden.
Add non-manufactured fertilizer, if not using a commercial fertilizer, by layering 2 to 4 inches over the surface of the garden. Non-manufactured fertilizer can include homemade compost, composted manure, well-rotted leaves or grass clippings and clover.
Turn the soil to mix in the fertilizer thoroughly. Typically adding fertilizer can be done in the spring, but if you're using manure, spread it on in the fall and wait until spring to mix it.
Add more non-manufactured fertilizer, if desired, and especially if you have sandy or clay soils. Compost and composted manure can improve the quality of your soil by adding nutrients, increasing drainage and lightening the consistency of the soil, allowing roots to move more freely through it.