Iris
Also known as: Iris spp.
10 types of iris
Blackberry Lily
2 yearsalso: Iris domestica, Leopard Lily, Belamcanda chinensis
Not a true lily — iris-relative with orange spotted flowers and blackberry-like seed pods.
Blue Flag
2–3 yearsalso: Iris versicolor, Harlequin Blueflag, Larger Blueflag, Northern Blue Flag
Native wetland iris with striking violet-blue flowers; excellent for rain gardens and pond margins.
Blue Juno Iris
2–3 yearsalso: Iris magnifica var. f. caerulea
Blue-flowered form of the magnificent Juno iris.
Douglas Iris
2–3 yearsalso: Iris douglasiana
Pacific Coast native with lavender-blue flowers; prefers dry summers and mild winters.
Japanese Iris
2–3 yearsalso: Iris ensata, Ensata Japanese Iris, Japanese Water Iris
Large showy blooms in purple, white, or pink; loves moist, acidic soil at pond edges.
Juno Iris
2–3 yearsalso: Iris magnifica, Magnificent Iris
Tall Juno iris with fragrant pale blue or white flowers; needs dry summer dormancy.
Rocky Mountain Iris
2–3 yearsalso: Iris missouriensis, Western Blue Flag, Wild Blue Iris
Native western iris with pale blue to lavender flowers; prefers meadows and moist ditches.
Siberian Iris
2–3 yearsalso: Iris sibirica
Elegant clump-forming iris with slender leaves and blue, purple, or white blooms; very hardy.
Stinking Iris
2–3 yearsalso: Iris foetidissima, Gladdon, Gladwin Iris, Roast Beef Plant
Evergreen species with dull flowers but spectacular orange seeds visible in split pods.
Yellow Mongolian Iris
2–3 yearsalso: Iris bloudowii
Small species iris with bright yellow flowers; hardy and drought-tolerant once established.
When & where
Germination
Spacing & depth
How to plant
Sow fresh seed in a prepared nursery bed in fall, or cold-moist stratify 8–12 weeks and sow in spring. Keep seedlings moist and in bright light. Grow on for a year or two before planting out to a permanent spot.
Pre-sow treatment
Cold-moist stratify 8–12 weeks; some species benefit from a warm period first.
Grower's tip
Irises are usually propagated by rhizome division, but growing from seed is rewarding for species and hybrids. Do not bury rhizomes too deeply when transplanting.
Soil preferences
Loose, well-drained soil — bulbs rot in wet feet.
6.0–7.0
Compost + bone meal or rock phosphate worked into the planting hole.
Watering
Water in at planting, then only during active growth. Let bulbs go dry during dormancy.
Deep watering at the base. Avoid overhead watering after leaves die back.
Overwatered: soft, mushy bulbs at harvest; basal plate rot. Underwatered: small bulbs, thin necks.
Either works — Top-water in-ground bulbs (garlic, onion, shallot, tulip, daffodil) at the soil surface — keep the crown mostly dry. Bottom-water forced bulbs and potted amaryllis. Stop watering entirely once foliage yellows and dies back.
Temperature tolerance
60–75°F (15–24°C) during growth
40–60°F (4–15°C)
Hardneck garlic, shallots, and daffodils need a cold winter to bulb properly. Tender bulbs (dahlia, gladiolus) must be lifted in cold zones.
Container growing
Yes — great in containers
8+ in deep, wide enough to space bulbs 2–3× their diameter
Deep pot for tulips and daffodils; shallow bowls for crocus.
Detailed harvesting
For garlic and onion: dig when the bottom 3 leaves brown and top leaves still stand. Loosen with a fork, don't yank. Cure whole plants 2–3 weeks in a warm, airy, shaded spot.
Post-harvest storage & preservation
After curing, trim tops and roots. Store hardneck garlic 4–6 months, softneck 8+ months in a cool (50–60°F), dry, dark spot with airflow. Never in the fridge.
Culinary, medicinal & other uses
Culinary staple (allium bulbs), cut flowers (tulip, daffodil, lily), forced blooms indoors, or perennial garden color.
Medicinal or traditional uses are shared for interest only — this is not medical advice. Consult a qualified professional before using any plant medicinally.
Seed saving
Propagate by offset bulblets, not seed — bulbs mature much faster from a clove/bulb than from seed.
Not applicable when replanting clones. Cross-pollinated seed rarely comes true.
Save the biggest, firmest bulbs each year and replant. Over generations you build a locally-adapted strain.
Your zone's planting calendar
Pick your USDA hardiness zone and we'll estimate the key dates for iris in your area. These are regional averages — always check your own last-frost forecast before sowing.
From your kitchen — grow iris from what you already have
Bulbs propagate from offsets and bulblets, not seed. Every year the parent bulb makes more of itself underground.
- 1At harvest or dormancy, lift the clump and gently split off the smaller side-bulbs.
- 2Cure the bulbs 2–3 weeks in a warm airy spot until the necks are dry.
- 3Save the biggest for eating and the medium-sized ones for replanting.
- 4Replant at the recommended time for this crop, point-up, at the depth listed above.
Storage: Bulb strains adapt to your garden year over year — the older your stock, the better it grows.
My Iris notes
Iris seeds on hand
Track packets and loose seeds you already have. Private to your account.
Par level — leave at 0 for no alert. Anything below par shows on Seed Starting and your shopping list.
Order more seeds
Running low? Reorder from one of these seed stores.
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