Soil Preparation

You may think it’s easy to dig a hole, place a plant in it, and use the same soil to cover the roots. But most soils can benefit from soil amendments.

Soil that is too sandy lets these drain through too quickly; soil containing too much clay is hard for water and plant roots to penetrate. The ideal soil, called loam, is crumbly and well aerated, with plenty of humus (organic) content. In a loamy soil, plant roots can travel long distances in pursuit of nourishment to support vigorous leaves and masses of colorful flowers.

But with very little effort, that same soil can be upgraded tremendously so the plants will become established more quickly, then grow faster, stronger and healthier.

Enhancing the soil will:

  • Improve the porosity, allowing more water and nutrients into the root zone
  • Reduce runoff compared to hard, crusty soil
  • Make oxygen available to the plant roots
  • Encourage roots to spread out and develop into a sturdy underground network to take in vital nutrients and moisture

For great results, some product makes a general purpose Garden Soil that replaces do-it-yourself mixtures of topsoil, peat and manure. It can be used for planting all types of annual and perennial flowers. It will provide the essential nutrients you need to improve soil condition and control moisture, and it has plant food already mixed in the soil.

Soil Fertility

Soil not only anchors plants but also holds the moisture and nutrients they need to grow and flower. A fertile soil has the proper balance of three essential plant nutrients: nitrogen, phosphorus and potassium. Flowering plants are generally less greedy in their fertilizer needs than are vegetables, but the application of a granular fertilizer, raked or watered into the soil surface at the start of the season, is good insurance. In general, the faster a plant grows, the more fertilizer it needs. If youre not sure of the fertility of your soil, use moderate amounts of a fertilizer with about twice as much nitrogen as phosphorus and potassium.

Soil pH

The pH of a soil is a measure of its acidity or alkalinity. Wooded areas often have acidic (low-pH) soil; deserts tend to be alkaline (with high pH). Although some flowering plants will fare better in one type of soil than the other, most plants recommended here will perform well in a wide range of soils.

You can determine the pH of your soil by asking a neighbor who gardens, by purchasing an inexpensive soil test kit, or by submitting a soil sample to a laboratory recommended by your county agricultural agent. Some garden centers will test your soil for free. Minor adjustments to soil pH can be made by adding lime (to acid soil) or soil sulfur (to alkaline soil). However, if your soil pH is extreme, adjusting it may be difficult; instead you may choose to plant your garden in raised beds filled with topsoil from a nursery.

Cultivated Soil

Most garden-worthy flowering plants need a good depth of loose, crumbly soil to allow roots to penetrate long distances in search of water and nutrients. Fortunately, most flowering plants do not need the deep cultivation that vegetables require. Digging to a depth of 1 foot — about one spade length — should suffice for a flower garden, even one planted with flowering trees and shrubs.

Preparing the Soil

Before setting plants into the ground, it pays to get the soil into tip-top condition. Without good soil, achieving a fine flower garden will be an uphill battle. Soil not only anchors plants but also holds the moisture and nutrients they need to grow and flower. Soil that is too sandy lets these drain through too quickly; soil containing too much clay is hard for water and plant roots to penetrate. The ideal soil, called loam, is crumbly and well aerated, with plenty of humus (organic) content. In a loamy soil, plant roots can travel long distances in pursuit of nourishment to support vigorous leaves and masses of colorful flowers.

To make your soil more loamy, you must load it with plenty of humus (organic) material in the form of compost, well-decomposed animal manure, leaf mold or bales of peat. Even soils that have been well maintained need to be topped up with organic material every year because the natural workings of sun, wind and rain tend to leach out nutrients and pack down the soil. Soil conditioner will also help neutralize overly-acidic or alkaline soil, which can impede the growth of some flowering plants.

Of the soil conditioners most commonly used, leaf mold is the most valuable because it holds moisture extremely well and because it has an ample supply of nutrients. Peat is the least desirable because it lacks nutrients. Buy peat or manure at a garden center, or check classified ads in a newspaper for sources of less-expensive compost. Leaf mold is so sought-after as a soil conditioner that many nurseries hoard it for their own use and rarely sell it. You can make your own by piling leaves into a corner of the garden and letting them rot down into lightweight, fluffy, rich humus. To speed this process, shred the leaves first with a lawn mower or leaf shredder. If you use a lawn mower, simply run the blades over small piles of leaves. Spade the soil conditioner over the soil surface to a depth of 3 to 4 inches and rake it in.

Cultivate the soil to the depth of a garden spade (8 to 12 inches), and comb the soil surface with the prongs of a garden rake. Use the flat back of the rake to break up any clods and make the surface even finer. When applying fertilizer, sprinkle granules over the soil surface before raking, at the rate recommended on the package. Take care not to tread on newly dug soil. If you must do so in order to plant, put down a wooden board to cushion your weight.

How to Amend Soil

There are two simple ways to improve your soil:

  • Spread enriched soil or amendments over the planting bed and till them into the soil.
  • Mix the enriched soil or amendments with the soil removed from the planting holes.

Both methods can turn almost any soil into a planting area in which your flowers will thrive.

If you are creating a new flowerbed in a contained area, you may even choose to dig out the area and re-fill it with the appropriate type of soil.