Garden borders can be created out of a wide variety of plants including shrubs, perennial flowers or ornamental grasses. Often times, perennial plants are the popular choice because they only need to be planted once and will continue to come back and bloom year after year. When choosing flowers for a garden's border, try mixing various types of plants for a more natural look.
The yellow tuft (Alyssum murale) is a perennial plant that typically grows to 18 inches in height. It prefers full sun exposure, and its yellow flowers bloom in the months of May to July. Yellow tuft requires well-draining soil, but it will perform well in both fertile and poor soil conditions. Cut back the stalks of the plant after the blooms die and lay a 1-to-2-inch layer of mulch over the roots during the winter for protection. Yellow tuft grows best in zones 6 to 8t and makes a good border for rock gardens.
Columbine (Aquilegia) thrives best in zones 3 to 9 with full or partial sun exposure. It will grow to a height of 2 feet and blooms red or orange flowers in April to June, depending on your growing zone. The columbine is a perennial plant that prefers well-drained, fertile soil conditions. Deadhead the blooms once they have expired, and prune stalks down to ground level once they have wilted. Columbine works well in unstructured or wild gardens and as borders in butterfly gardens.
Butterfly weed (Asclepias tuberosa) grows in full sun to an average height of 2 to 3 feet. It is a very showy plant with orange flowers that typically bloom from June to August in zones 3 to 9. Butterfly weed needs well-draining soil and is considered drought tolerant. It will reseed itself, but if you wish to stop the spread of butterfly weed remove the seed pods. As the name implies, butterfly weed is recommended as a border for butterfly gardens.
Mountain bluet (Centaurea montana) reaches a height of 2 to 2-1/2 feet. This perennial grows best in zones 3 to 8 and produces blue flowers in the months of June to September. Deadhead the blooms after they expire to encourage new blooms. Mountain bluet is drought tolerant but needs rich, fertile soil to thrive. It is an aggressive plant in cooler climates and dividing the plant every two to three years is recommended. Mountain bluet is recommended as a suitable, all-around border plant for any type of flower garden.