An unusually hot summer in colder climates or a string of freezing nights in a warm weather state will not bother a number of flowers and other types of plants adapted to both hot and cold conditions. These plants have the most members within the ranks of trees, deciduous shrubs, perennials and needled evergreens. Their versatile nature when it comes to handling temperature extremes make them valued landscaping features.
The lead plant is a deciduous shrub with a range extending from Canada southward through Mexico, so cold and heat do not deter its growth. Lead plant flowers develop on spikes and are purple-blue, with the plant growing to 3 feet tall. Another deciduous shrub for hot and cold is the common ninebark, one with many stems and turning out white flowers in late spring. Ninebark grows from USDA plant hardiness zones 2 through 8, covering the area from Quebec to Tennessee. Other hot-cold shrubs include the shrub rose, false spirea and various kinds of viburnum bushes -- all handle the temperatures between zones 2 and 8.
Hollyhock is a short-lived perennial plant that grows from USDA zones 2 through 10 but has no ability to survive a cold winter in wet areas. Hollyhock flowers on stiff stems as tall as 8 feet, with the blooms in red, pink or white. Prairie blue-eyed grass, Arctic poppy, lily-of-the-valley and common fleabane all grow into the cold of zone 2 but also thrive when planted in zones as warm as 7 or 8. Thimbleweed is a flowering perennial for shade and one that blooms during the spring in woodland or shade gardens. Thimbleweed's planting range is from zone 2 through zone 8.
The red cedar excels in a warm environment such as zone 9 or one as chilly as zone 2. Growing to 50 feet as a tree, the species comes in hybrid forms such as Gray Owl, which is a 3-foot tall shrub. Red cedar works as a foundation plant, windbreak or specimen tree. The Austrian pine cultivar Globosa viridis is a needled evergreen shrub for zones 2 through 8, growing to between 2 and 5 feet and suitable for rock gardens. Dwarf mountain pine, Scotch pine and a few kinds of American arborvitae have hot-cold tolerance on the same level.
Box elder has one of the widest ranges of North American trees, growing from USDA zone 2 to zone 10. It colonizes sites with poor quality soil, as long as they are sunny. Willow species such as golden willow and white willow withstand both heat and bitter cold. The quaking aspen stands up to the frozen Alaska winter and a hot summer in the upper Midwest. The eastern cottonwood is a close relative, with red male flowers, green female flowers and a tolerance to hot and cold climates. Hackberry and chokecherry are a pair of flowering, fruit-producing trees for both types of climates.