Dutch Iris in Zone 8a & 8b

Iris × hollandica

Yes, Dutch iris grows in zones 8a and 8b. Plant it outside in Sep–Nov. For a fall crop, plant out in Sep–Nov.

When to plant Dutch iris in zone 8b

Zones 8a and 8b share the same average frost dates, so this page covers both.

Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.

WindowFall window
Start indoorsNot typically started indoors
Direct sow / transplant outsideSep–Nov
Estimated bloom~210 days after direct-sowing

Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1.5-2 ft.

Zone 8b dates sourced from www.johnscheepers.com.

Fall window: the last sowing date is the average first frost minus days to maturity, the method in Purdue Extension's fall garden guide, which lists Dutch iris for late-summer planting.

Plant alongside it in zone 8b

These go outside within two weeks of Dutch iris in zone 8b, so one planting day can cover them.

Dutch Iris
Photo: Martin de Lusenet from Heemskerk, Netherlands via Wikimedia Commons, CC BY 2.0, cropped.

Dutch iris grows from a true bulb, not the thick rhizome most gardeners associate with bearded iris, and the flowers look closer to what florists sell than to a typical garden iris: tall, slender stems topped with blue, purple, yellow, or white blooms in early summer.

How Dutch iris fits zone 8's season

Zone 8b's frost-free window runs about 230 days, from March 25 to November 10. Dutch iris goes in during the fall and grows through the winter, so it isn't limited by this window: expect first bloom about 210 days after planting.

Dutch Iris planting windows in every zone

Zone 8b is highlighted. Useful for comparing against a neighbouring zone, or for a garden somewhere else.

ZoneStart indoorsSow or plant outBloom
5a & 5bFall windowNot usuallySep–Nov~210 days after direct-sowing
6a & 6bFall windowNot usuallySep–Nov~210 days after direct-sowing
7a & 7bFall windowNot usuallySep–Nov~210 days after direct-sowing
8a & 8bFall window (your zone)Not usuallySep–Nov~210 days after direct-sowing

Bloom dates are about 210 days after the sow or plant-out date.

Good companions

No well-established companions for Dutch iris.

Where to buy Dutch iris bulbs

We haven't vetted bulb/tuber suppliers yet. Our seed-supplier list below doesn't carry these. The growing-guide source cited above is a good starting point for where to buy.

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See it growing

Search YouTube for "growing Dutch iris" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)

← Back to the full zone 8b calendar · Plan your beds in the Garden Designer →

Growing Dutch Iris in USDA zone 8b

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Growing Dutch Iris in USDA zone 8b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.

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