Old-fashioned and easy to grow, columbines are a long-time garden favorite. They have delicate green or blue-green leaves that are usually divided and fan shaped, and spurred, bell-shaped flowers on leafy stems. Columbines bloom in the spring and summer with colors ranging from subtle shades of white and yellow to darker hues of red, blue, and nearly black, depending on the variety. Some varieties have flowers that are bicolored, and many attract butterflies and hummingbirds.
- Common name: Columbine
- Botanical name: Aquilegia spp.
- Zones: 3 to 9, depending on species
- Size: To 3 feet tall, depending on species
- From: Areas of Europe, Asia, and North America
- Family: Ranunculaceae (Ranunculus family)
- Sun: Partial shade is best; plants tolerate full sun in some conditions. Afternoon shade is beneficial in hot-summer areas.
- Soil: Moist and well drained. Most prefer soil with lots of organic matter and an organic mulch.
- Moisture: Water during times of drought.
- Mulch: Lay a 2- to 3-inch layer of mulch over the soil around the plants. Use winter mulch only after the soil has frozen.
- Pruning: Cut back plants in autumn after freezing temperatures arrive or in spring before plants begin to grow.
- Fertilizer: Fertilizer is generally not necessary in soils that are rich in organic matter.
- Seed: Plant columbine seed in spring. Columbines may naturally self-sow, but seed from hybrid plants generally won't grow into plants similar to the parent.
- Aphids: These small insects often appear on new growth. Spray them off daily with a stream of water; they will not attack a plant after being knocked off. Use an insecticidal soap or neem-oil spray if infestations are severe.
- Fungal diseases: If portions of the plant rot or have spotted leaves, the plant may have a fungal disease. To prevent these diseases, avoid wetting the foliage, especially after mid-afternoon. Divide plants so the clumps do not become especially large. This will ensure good airflow, which discourages fungal diseases.
- Leafminers: If leaves look like they have tunnels through the middle of the tissue, it's probably the work of leafminers. To deter this insect pest, destroy affected leaves and lay mulch around the base of the plants to keep larva from burrowing into the soil to pupate. Leafminer damage is more unattractive than harmful.
- Powdery mildew: This disease tends to appear in mid- to late summer. Affected leaves develop a covering of grayish powder and fall off. To deter the disease, prune the plant to maintain good airflow and avoid wetting the foliage in afternoons and evenings.
- Slugs/snails: Slugs and snails tend to feed at night. To deter them, surround plants with a ring of horticultural-grade diatomaceous earth or slug bait. Some gardeners lay copper strips around plants, but this is not always successful. If slugs are not particularly numerous, set out shallow containers of stale beer at ground level. Slugs will be attracted to the beer, and will crawl into it and drown.
- Columbines are usually short-lived. After a plant blooms, you can increase its life span by cutting it back to about 6 inches tall. A new flush of foliage will grow and the plant will remain more compact for the rest of the season.
- Aquilegia caerulea: Rocky Mountain variety grows to 2 feet tall and has deeply lobed leaves. Blue and white flowers appear in late spring and early summer. Zones 3 to 8. Native to areas of North America.
- Aquilegia canadensis: Red and yellow blooms. Grows to 2 feet tall. Zones 3 to 8. Native to areas of North America.
- Aquilegia chrysantha: Deeply divided leaves and golden-yellow flowers. Grows to 3 feet tall. Zones 3 to 8. Native to areas of North America.
- Aquilegia flabellata: Fan columbine grows to 1 foot tall and has deeply lobed, blue-green foliage and blue, white, pink, or cream flowers in early summer. Zones 4 to 9.
- Aquilegia McKana hybrids: Bicolored flowers in many colors. Grow to about 3 feet tall. Zones 3 to 9.
- Aquilegia ‘Norma Barlow': Hybrid with double red flowers. Grows to about 3 feet tall. Zones 3 to 9.
- Aquilegia vulgaris: Common columbine with blooms in shades of blue, purple, pink, white, and red. Grows 3 feet tall. Zones 3 to 8.