Plan the perfect garden with our interactive tool →

Soil Types & Plant Growth

The type of soil that you plant in can make a big difference in plant growth. Strong, healthy plants require soil with good structure and texture, the proper pH level, and the proper nutrients. Well-balanced soil will produce beautiful plants with lush foliage, brilliant blooms and abundant, healthy fruits. The right type of soil is really the key to healthy plant growth.

Loose Soil vs. Clumping Soil

Good soil structure is loose and granular, and can be seen with a visual inspection of the soil. Soils that are too loose allow moisture and nutrients to quickly leach out of the soil. Plants grown in loose soil may not get the nutrients they require and could suffer stress from not receiving adequate moisture. Soil that forms dense clods when worked can be difficult for roots to push through, resulting in small, underdeveloped plants.

Fine vs. Coarse Soil

The texture of the soil determines the availability of nutrients for plants. Soil texture refers to the fineness or coarseness of the soil’s mineral matter and effects plant fertility, water retention and air circulation within the soil. When soil is held in the hand, a gritty feel indicates high sand content, while a slippery soil means there is a high presence of clay, and silt has a greasy feel to it. Minerals and nutrients in the soil are where plants get the majority of their nourishment. An ideal garden loam contains about 40% sand, 40% silt and 20% clay.

Acidic vs. Alkaline Soil

When the soil pH is not in balance with the plant’s needs (like acidic plants growing in alkaline soil), plants will not thrive. Most plants like a soil acidity that falls in mid-range, about 7.0. To learn your soil’s pH, the soil must be tested. Home testing kits are available or a soil sample can be sent to your local, county or state agricultural agency. If your county extension service does the testing, they will usually send recommendations for fertilizer and soil amendments with your results.

Nutrients in Soil

An imbalance of nutrients can stunt plant growth or even cause them to die. The three main nutrients that plants get from soil are nitrogen, phosphorus and potassium.

Nitrogen promotes lush foliage and better productivity. Plants that are nitrogen deficient have older leaves that turn yellow, while younger leaves appear unaffected.

Phosphorus promotes rapid growth, strong root systems and big blooms. Purplish or bronze-colored leaves indicate a phosphorus deficiency.

Potassium builds protein, aides in photosynthesis, and builds disease resistance. A lack of potassium is indicated by leaves, with yellow, translucent spots and browning edges. Soil also provides secondary nutrients and minerals that plants need. If a nutrient imbalance is indicated, organic fertilizers made from natural plant and animal materials may correct the problem.

Organic Matter in Soil

Good soil fertility and higher plant productivity result from organic matter in the soil. Increasing organic matter improves soil structure and increases biological activity, resulting in better plant yields. The best source of organic matter is compost, but turning raw organic material directly into the soil is also effective. One to two inches of compost per year (or four inches of fluffy material, like straw) will help to ensure strong, healthy plant growth.

Garden Guides