Iris

Iris

Iris germanica

Plant out 8 weeks before your first fall frost. Space plants 12 in (30 cm) apart.

Photo: Hüseyin Cahid Doğan, CC BY-SA 4.0 · source

When to plant

Timed from your frost dates, so it holds wherever you garden. Give yours and every step below becomes a date.

See the dates for your garden

Enter your average last spring frost and first fall frost. Every timing on this site turns into a calendar date. Not sure of yours? Your local extension service or a search for “last frost date” and your town will tell you; the app finds them from your location.

Last spring frost
First fall frost

Saved in this browser only. Nothing is sent anywhere.

Optimal Fall Planting (Rhizomes)

RootRecommended
  1. Plant out8 weeks before your first fall frost

Growing iris

Spacing in the row
12 in (30 cm)
Between rows
18 in (46 cm)
Planting depth
Rhizome at or just below the soil surface, top slightly exposed; do not mulch over it
Sun
Full Sun
Mature height
1-3 ft
Hardy to
USDA zone 3
Life cycle
Perennial

Feeding

How often
Twice a year: early spring and after bloom. Use a low-nitrogen fertilizer such as 5-10-10 or bone meal spread around, not on, the rhizomes; high nitrogen invites soft rot.

Your iris, planned to the day.

Canopy turns these timings into dates from your own frost data, places every plant at its spacing on your garden map, and tracks it all the way to harvest.

Add iris to your planting calendar →