Difference between potting soil and soil improver?

Potting soil and soil improver are both used in gardening and landscaping, but they have different purposes and characteristics. Here are the key differences between the two:

1. Composition

Potting soil, also known as potting mix or container mix, is specifically formulated for use in containers and pots. It is a blend of various components like peat moss, vermiculite, perlite, and sometimes compost or organic matter. The purpose of potting soil is to provide a lightweight, well-draining, and nutrient-rich medium for growing plants in containers. It is typically sterilized to reduce the risk of pests and diseases.

Soil improver, on the other hand, is used to amend existing garden soil to improve its structure, fertility, and moisture-holding capacity. It is typically made from organic materials such as compost, well-rotted manure, leaf mold, or other natural additives. Soil improvers are used to enhance the quality of garden soil, making it more suitable for plant growth by increasing its organic matter content and improving its ability to retain water and nutrients.

2. Application

Potting soil is used specifically for container gardening, where plants are grown in pots, containers, hanging baskets, or indoor planters. It provides the necessary support and nutrients for plants grown in confined spaces. Potting soil is designed to have good drainage and aeration properties, which help prevent waterlogging and promote healthy root growth.

Soil improver, on the other hand, is used to enhance the quality of existing garden soil. It is typically mixed into the soil in garden beds, vegetable patches, or larger outdoor plantings to improve its overall fertility, structure, and waterholding capacity. Soil improvers are beneficial for improving the health and productivity of garden soil over time.

3. Nutrient Content

Potting soil is usually pre-mixed with nutrients to support plant growth in containers. It often contains a balanced blend of macronutrients (nitrogen, phosphorus, potassium) and micronutrients necessary for healthy plant development. The nutrient content of potting soil can vary depending on the brand and specific formulation.

Soil improvers, while they may contain some nutrients, are primarily focused on improving the physical properties of the soil. They enhance soil structure, increase organic matter content, and promote beneficial microbial activity, which indirectly benefits plants by creating a more favorable growing environment. Soil improvers primarily enhance the soil's ability to retain moisture, nutrients, and air. In summary, potting soil is designed for container gardening, providing a lightweight, well-draining, and nutrient-rich medium for potted plants. Soil improvers, on the other hand, are used to amend garden soil, improving its structure and fertility for better plant growth in outdoor gardens.