Tough Flowers for Extreme Gardens
For goof-proof results in cold conditions, count on these plants.
Gardening in cold climates is challenging, but with these plants, you can count on goof-proof results.
Delphinium
Botanical name: Delphinium.
Bloom time: Summer; may bloom again in autumn if cut back.
Hardiness: Zones 3 to 7.
Size: Most are 3'-7'; some dwarf species are available.
Light needs: Full sun.
Care tips: Choose a planting site with good drainage and air circulation to ward off diseases and pests. Most tall cultivars need to be staked, but wear gloves when handling them; they can cause allergic reactions.
Rugosa Rose
Botanical name: Rosa rugosa.
Bloom time: Spring to autumn.
Hardiness: Zones 2 to 8.
Size: 3'-8' high; 8' wide.
Light needs: Full sun.
Care tips: This plant prefers moist, well-draining soil but will tolerate a wide variety of conditions, including sandy soil. Plant small, bare-root roses while they're dormant in spring. Container plants may be added to the landscape anytime during the growing season.
Mountain Bluet
Botanical name: Centaurea Montana.
Bloom time: Late spring to midsummer.
Hardiness: Zones 3 to 8.
Size: Up to 18" high and 24" wide.
Light needs: Full sun to partial shade.
Care tips: Prefers moist, well-draining soil. This plant self-seeds readily, forming a thick mat that's ideal for borders, naturalizing or rock gardens. Bluets also attract bees and butterflies.
Asiatic Lily
Botanical name: Lilium species and
hybrids.
Bloom time: From early summer through early autumn; timing varies with cultivar.
Hardiness: Zones 3 or 4 to 8.
Size: 2'-7' high; 1'-2' wide.
Light needs: Full sun to partial shade.
Care tips: Plant in fall or use precooked bulbs when planting in spring. Plants are often available from garden centers for spring and summer planting. To propagate, dig up dormant bulbs after foliage dies back and separate bulblets for replanting. Bulbs need a cold period while dormant. Gardeners in Zones 10 and 11 can buy precooled bulbs or species adapted to short, mild winters.