Which plant hybrid species is primarily known for ornamental use in gardens and landscapes?

Dahlia hybrids are primarily known for their ornamental value in gardens and landscapes due to their striking flowers that come in a wide array of colors, shapes, and sizes. They are highly valued by gardeners for their vibrant blooms and the variety of forms available, making them suitable for decorative flower beds and borders. Typically, dahlias are appreciated for their ability to bloom continuously from summer to fall, adding long-lasting color to gardens.

In contrast, while Crocus species are also ornamental, they are more commonly associated with early spring blooming and do not have the same level of popularity for extensive garden landscapes as dahlias. Asparagus densiflorus, known as asparagus fern, is often used for indoor decoration rather than primarily outdoors. Chlorophytum comosum, or spider plant, is valued mainly for its houseplant qualities rather than for use in traditional landscape gardening. Thus, the focus on dahlias as garden ornamentals distinctly sets them apart within this context.