Blue Iris, Salt Marsh Iris, Butterfly Iris
Elegant and vibrant, Blue iris (Iris spuria) is a perennial iris known for its tall stature and stunning blooms, making it a captivating addition to any garden.
Native from Africa to temperate and tropical Asia and Europe, Iris spuria, commonly known as Spuria Iris or Blue Iris, is one of the tallest irises.
Habit and Size: Blue iris is an elegant rhizomatous perennial, reaching a height of 3-5 feet (90-150 cm) and forming an upright clump of narrow, tall, and sword-like leaves. The foliage provides an attractive architectural element in the garden even when the plant is not blooming.
Flowers: The flowers of Spuria Iris are beardless, large, and showy, up to 6 inches (15 cm) wide, with slim standards and falls. Graceful, they exist in a wide range of colors, including blue, yellow, white, violet, and brown. They add drama to the garden and will reward you with beautiful blooms and long-lasting cut flowers.
Blooming Season: Blooming typically occurs in late spring to early summer, usually 1 to 2 weeks after the bloom of the bearded irises. Each plant can have multiple flower stalks, and each stalk generally bears 3 to 4 buds on each branch. It should be noted that both height and bud counts may vary with regions: shorter stalks and reduced bud counts will be obtained in colder climates than in warm climate areas.
Hardiness: Spuria Irises are very hardy and can withstand temperatures well below freezing, making them suitable for USDA hardiness zones 3 through 9.
Uses: These irises are particularly useful in garden design due to their tall stature and striking flowers. They can serve as the backdrop in mixed borders, be grown in mass plantings, or be used in cut flower arrangements.
Pollinators: Like other irises, they attract a variety of pollinators, including bees and butterflies.
Toxicity: All parts of the plant are toxic if ingested, so it’s essential to keep this in mind if you have pets or young children.
Deer and Rabbit: Deer and rabbits usually avoid these plants, making them a good choice for gardens that experience these pests.
Drought Tolerant: Iris spuria is known for being drought-tolerant once established, but it prefers well-drained soil and full sun to partial shade.
Growing Iris Spuria can offer several benefits for your garden:
Beauty and Variety: Iris Spuria offers beautiful, tall, and slender blooms that can reach up to five feet (150 cm) in height. They come in a variety of colors, adding a vibrant mix of hues to your garden.
Low Maintenance: Iris Spuria is known for its hardiness. It thrives in full sun and well-drained soil, and once established, it requires minimal care.
Versatility: Due to their height, Iris Spuria can be used as a backdrop for lower-growing plants. They can be planted in beds, borders, or along ponds and streams, offering a lot of versatility in landscape design.
Attracts Pollinators: Like other Irises, the Spuria Iris can attract butterflies and other pollinators to your garden, promoting biodiversity.
| Hardiness |
3 - 9 |
|---|---|
| Heat Zones |
5 - 9 |
| Climate Zones | 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 |
| Plant Type | Perennials |
| Genus | Iris spuria |
| Exposure | Full Sun, Partial Sun |
| Season of Interest |
Spring (Late) Summer (Early) |
| Height |
3' - 5' (90cm - 150cm) |
| Spread |
2' - 3' (60cm - 90cm) |
| Spacing |
24" - 36" (60cm - 90cm) |
| Maintenance | Average |
| Water Needs | Average |
| Soil Type | Clay, Loam, Sand |
| Soil pH | Alkaline, Neutral |
| Soil Drainage | Moist but Well-Drained, Well-Drained |
| Characteristics | Cut Flowers, Showy |
| Tolerance | Drought, Deer, Rabbit |
| Attracts | Bees, Butterflies |
| Landscaping Ideas | Wall-Side Borders, Beds And Borders |
| Garden Styles | City and Courtyard, Coastal Garden, Informal and Cottage |
Incorporating Iris Spuria into your garden design can add height, color, and structure to your space. Here are some ideas on how to use these striking plants:
Borders and Beds: Iris Spuria’s height and vibrant blooms make them perfect for the back or middle of flower beds and borders. They add vertical interest and a burst of color that contrasts beautifully with lower-growing plants. Consider using them as a backdrop for shorter plants with complementary or contrasting colors.
Pond and Stream Edges: These Irises thrive in moist soil, making them perfect for planting around the edges of ponds or streams. They provide a striking focal point and add structure to these areas.
Mixed with Grasses: Iris Spuria can look stunning when interplanted with ornamental grasses. The grasses add texture and movement, while the Iris Spuria adds height and vibrant pops of color.
Mass Planting: For a truly dramatic effect, consider mass planting Iris Spuria. A large grouping of these tall, colorful flowers can be a breathtaking sight.
Containers: For those with smaller gardens or just a patio, Iris Spuria can also grow successfully in deep containers. This allows you to enjoy their beautiful blooms even if you’re limited in space.
Remember to account for their height and their need for full sun when deciding where to place them in your garden design. The beauty of Iris Spuria, combined with its versatility, makes it an excellent choice for many garden layouts.
Iris spuria can be successfully grown alongside various other perennials, many of which can complement the distinctive features of the Iris. Here are some suggestions for companion plants:
Salvia (Salvia spp.): These plants are beloved for their vibrant flowers and sage-like scent. They can create a delightful contrast to the tall, elegant form of Iris spuria.
Nepeta (Catmint): With its lavender-blue flowers and grey-green, aromatic foliage, Nepeta provides a lovely contrast to the tall, upright form and vibrant blooms of Iris spuria. Both plants prefer full sun and well-drained soil.
Euphorbia seguieriana: The chartreuse flowers of this Euphorbia species can create a striking contrast with the typically blue or purple flowers of Iris spuria. Both plants are drought-tolerant and prefer sunny locations.
Stipa gigantea (Giant Feather Grass): The tall, arching stems and golden oat-like flowers of Stipa gigantea provide a lovely backdrop for the bold flowers of Iris spuria. Both plants enjoy full sun and well-drained soil.
Iris ensata (Japanese Iris): Pairing Iris spuria with another species of iris can create a display of varied colors, heights, and bloom times. Both species enjoy similar growing conditions of full sun to partial shade and moist, well-drained soil.
As with any garden design, it’s important to consider the specific needs of each plant in terms of light, soil, and moisture to ensure they’ll thrive together.
Growing Iris spuria can be a rewarding experience as it adds distinctive color and structure to the garden. Here are some general steps on how to grow Iris spuria:
Choosing a location: Iris spuria needs full sun, at least six hours a day, for the best flowering. Partial shade is tolerated, especially in areas with extremely high summer temperatures. However, both flowering performance and disease resistance may be altered. The soil should be humus-rich, neutral to slightly alkaline, and well-drained. Heavy clay soils may need amending with compost or other organic matter to improve drainage.
Planting: The best time to plant Iris spuria is in mid to late summer. The rhizomes (a type of bulb) should be planted about 2 inches (5 cm) deep and 24-36 inches (60-90 cm) apart. Space them far enough apart to grow in the same location for years as spuria irises resent being transplanted. They usually do not bloom the first year after planting. The second year should produce several bloom stalks.
Watering: Water the plants well after planting and maintain moisture in the soil for the first few weeks while the plant is establishing. Once established, Iris spuria is quite drought-tolerant, but it will appreciate regular watering during dry periods. While consistent moisture should be provided during the growing season, wet soils must be avoided to avoid rot issues. Less moisture is needed after blooming since most Spuria irises are summer dormant (Do not water your spuria irises when dormant as this will cause rot).
Feeding: They are very heavy feeders, so make sure you fertilize them regularly prior to bloom. Apply a balanced slow-release fertilizer in early spring, just before new growth begins. Avoid heavy applications of nitrogen, which can lead to lush foliage at the expense of blooms.
Mulching: A layer of mulch around the plants can help to conserve moisture and suppress weeds. Be careful not to mound the mulch up against the plants, as this can cause rot.
Pruning: Deadhead spent flowers and remove any dying foliage in fall. Old flower stems can be cut down after blooming is over, not only for neatness but to allow air to reach the rhizomes.
Dividing: Every 3-4 years, you may need to divide the plants if they become crowded or if flowering decreases. The best time to do this is shortly after flowering, in late summer or early fall.
Pest and disease control: Iris spuria is generally quite disease-resistant, but keep an eye out for slugs, snails, thrips, gray mold, mustard seed fungus, or crown rot.
Tips to get your spuria irises to bloom:
Remember that while Iris spuria is a sturdy plant, it will benefit from some care and attention, especially in the early stages of growth. Once established, these plants can provide many years of beauty in the garden.
Gap Photos/Paul Debois/ Christa Brand/Martin Staffler
| Hardiness |
3 - 9 |
|---|---|
| Heat Zones |
5 - 9 |
| Climate Zones | 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 |
| Plant Type | Perennials |
| Genus | Iris spuria |
| Exposure | Full Sun, Partial Sun |
| Season of Interest |
Spring (Late) Summer (Early) |
| Height |
3' - 5' (90cm - 150cm) |
| Spread |
2' - 3' (60cm - 90cm) |
| Spacing |
24" - 36" (60cm - 90cm) |
| Maintenance | Average |
| Water Needs | Average |
| Soil Type | Clay, Loam, Sand |
| Soil pH | Alkaline, Neutral |
| Soil Drainage | Moist but Well-Drained, Well-Drained |
| Characteristics | Cut Flowers, Showy |
| Tolerance | Drought, Deer, Rabbit |
| Attracts | Bees, Butterflies |
| Landscaping Ideas | Wall-Side Borders, Beds And Borders |
| Garden Styles | City and Courtyard, Coastal Garden, Informal and Cottage |
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Create a membership account to save your garden designs and to view them on any device.
Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.
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