Tall yellow perennial flowers may be used as accent plants, border plants or specimens in the landscape. Yellow flowers make a striking combination when paired with purple foliage. Perennials save time and money for gardeners as they return year after year. Some perennials grow from bulbs or underground rhizomes. Shrubs that die back in winter and grow back in spring can be used as perennials.
A favourite of gardeners everywhere, the day lily blooms from late spring to fall. The trumpet flowers are showy above lance-shaped bright green leaves. Each stem have several flowers. The day lily comes in many colours, including shades of yellow in heights that range from 8 inches to 5 feet. They tolerate drought and do well in different soil types, but will perform best in well-drained soil with plenty of organic material. The perennial day lily can live many years in optimum conditions. These plants are highly cultivated and many hybrids are suited to various climates.
Peonies are unrivalled in the landscape for attractive green leaves and large, profuse blooms. Hybrid yellow peonies are available. Peonies require a chilling period, so they do best in U. S. Department of Agriculture (USDA) hardiness zones 2 to 8 where winters are colder. They grow rapidly in late spring to early summer, forming an attractive mound of green leaves on plants that are from 2 to 4 feet tall. Peony flowers last about one week, but the plant will continue blooming for many years. Peonies bloom in full sun and tolerate many soil types as long as they are well-drained.
The attractive and versatile African iris grows 5 to 7 feet tall when standing in water and 2 to 3 feet when planted in soil. The leaves are upright, thin and lance-shaped. Flowers rise on tall stems and last a few days. Although they do not produce profuse blooms, irises bloom throughout the year in USDA hardiness zones 8 through 11. They have few pests or diseases but do not tolerate well salty or coastal conditions. Iris flowers are typically white, but there are yellow hybrids available. The African iris is a perennial that will last many years.
Forsythia is a yellow flowering shrub that blooms profusely in early spring from USDA hardiness zones 3 to 8. Gardeners in zone 3 should use the hybrid 'Meadowlark' produced jointly by the University of South Dakota and the University of North Dakota. Delicate yellow flowers cover the branches of forsythia before leaves appear. Forsythia make a striking accent plant and can be used for borders and hedges. The mature plant can grow to 8 feet tall and is suited for many different soil types. It blooms best in full sun.