Perennial flowers come in all shapes, sizes and colors and the fact that they last for many years makes them a good choice for a garden. Unfortunately, they also make a good meal for deer, unless you plant varieties that deer do not like. Sometimes it is the fragrance that keeps them away and sometimes it is the taste--one nibble and deer leave it alone. Though no plant is "deer-proof," a very hungry deer will eat anything that is available, University of Colorado Extension specialists say in "Preventing Deer Damage," planting deer-resistant perennial flowers at your garden's outer borders should keep it relatively safe from grazing deer.
Anise hyssop (Agastache foeniculum) produces small lavender/blue flowers and leaves that have the taste and smell of anise. It is a herb, related to mint, that is used to make tea. It is also considered a wildflower. The plant grows 2 to 4 feet tall and 1 foot across. It likes full sun and well-drained to dry soil. The plant is hardy in U.S. Department of Agriculture Plant Hardiness Zones 4 to 9, all but the one coldest and the one hottest zones in the continental United States.
Basket-of-gold (Aurinia saxatilis) grows low to the ground, just 8 to 12 inches high. The plant produces thin, grey-green leaves and dense clusters of bright yellow flowers from spring through summer. It will spread wider than it will grow tall. Basket-of-gold can stand up to a light drought and likes a rocky, poorly fertilized soil and full sun. If the soil is too rich or if it gets too much shade, the plant will produce more stems, giving it a “leggy” look. The plant does best when used as a ground cover or in a rock garden. It is hardy in zones 4 to 8.
Adam's needle (Yucca filamentosa) produces spiky evergreen leaves about 1 inch wide and from 2 to 3 feet in length. The leaves grow out from a single point and fan out to form a rosette. The stems grow to a height of about 12 feet. The warmer it is, the taller they grow. Each stem will hold dozens of 2-inch white flowers. The plant will die after the fruit appears, but produces new buds around the base of the original plant which will become new plants. Its natural habitat is dry, sandy or rocky and is hardy in zones 5 through 10. Adam’s needle likes full sun, but can take very light shade, dry soil and is drought tolerant. It is a good choice for a rock garden and goes well with other perennials.