Compact herbaceous plants used to add color to a landscape are known as:

The term for compact herbaceous plants used to add color to a landscape is bedding plants. Bedding plants are typically used in annual or seasonal flower beds to provide vibrant colors and aesthetic appeal in gardens, patios, and other landscape designs. These plants are specifically selected for their ability to bloom profusely in decorative arrangements and can often be replaced with different varieties throughout the seasons.

Bedding plants are usually chosen for their attractive flowers and foliage, and they are often cultivated in pots or containers for easy transport and arrangement in the landscape. They are distinct from other plant types in how they are used primarily for short-term displays rather than for long-term growth or coverage.

Perennials and annuals represent categories of plant life cycles rather than a specific use in landscaping design. While perennials can certainly contribute color, they typically return year after year, and annuals complete their life cycle in one growing season, but the focus here is on the compact, colorful plants specifically arranged for ornamental purposes, aligning more closely with the definition of bedding plants. Ground covers are generally low-growing plants used primarily for covering the ground to prevent erosion and weeds, rather than for their color and visual impact.