How to Prepare Soil for Planting

Growing a vibrant, healthy garden starts well before planting with soil preparation. The soil is the foundation of any garden. Preparing the soil the right way is key to the garden's long-term success. Whether you plan to plant a new vegetable garden, get a perennial flowerbed ready or add a shrub bed to the landscape, putting extra effort into the soil will pay off as your new garden matures.

Prepare the soil in fall if you want to plant annuals and tender perennials in spring. For fall plantings of shrub beds and hardy perennials, however, prepare new beds the spring prior to planting.

Why: Preparing a garden bed a full season before you plant gives weed eradication efforts a chance to work and allows nutrients and amendments to mix with the soil. If you don't have time to wait a full season, then prepare the bed three to four weeks before planting.

In mild, Mediterranean climates and coastal areas where winter frosts are mild or nonexistent, get the soil ready in winter or early spring, and then plant the following fall or early winter.

Working soil when it is too wet damages the soil structure by compacting its particles. Wait until the soil is moist and crumbly before you till, dig or add amendments. If it is muddy or sticky, wait a few weeks for the earth to dry.

Clear weeds and grass from new beds. You can smother them by starving them of light. Start that process in fall by spreading newspaper six sheets deep on top of the weeds and grass. Overlap the sheets' edges so that weeds and grass can't push through the seams. Cover the newspaper immediately with a 3-inch-deep layer of heavy mulch, such as compost or manure.

Use black-and-white newsprint rather than glossy advertisements and magazines, which contain chemicals and don't break down effectively.

In spring, till the newspaper, mulch, and dead weeds and grass into the soil. Newspaper, compost and manure break down over the winter months so don't need to be cleared away. The paper pulp and compost or manure add important organic materials to soil. Incorporate the materials 12 inches deep in the soil.

Turning the soil breaks up its clumps and loosens the earth, making it easier for new plants to establish strong, extensive root systems. Turn the soil to a depth of 12 inches with either a tiller or garden fork. Break up all clumps with a shovel or garden fork, and move stones and sticks out of the bed.

Add organic amendments such as compost or seasoned manure before planting to improve the soil. Organic amendments can be added anytime from the season before planting right up to the day of planting. Vegetable gardens, shrub beds, and perennial and annual flower gardens all benefit from this step.

If you use plant-based compost, then apply a 2- to 3-inch-deep layer of it each of the first four years. Then scale back to a 1- to 2-inch layer each later year. Incorporate the compost 6 to 8 inches deep in the soil each year.

Seasoned manure is an alternative to plant-based compost, but incorporate only a 1-inch-thick layer of it with the soil per year. Overuse of manure can increase the salt content in soil, hindering plant growth in the future.

Whether you intend to plant annuals, perennials or shrubs, adding balanced fertilizer to the bed will improve the nutrients in the soil. Use a granular 8-8-8 or 10-10-10 fertilizer; the numbers indicate that both fertilizer blends have equal amounts of nitrogen, phosphorous and potassium, or NPK. Dig to incorporate the fertilizer with the top 12 to 15 inches of soil. A 100-square-foot planting area requires 2 cups of the fertilizer.