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When to plant Irises in Rush County, KS

In Rush County, Irises is a single-season spring crop — there's no second fall window. Plant May 1–May 15 for an 60–100-day harvest, finishing well before the October 15 first frost.

When to Plant Irises in Rush County, KS

Rush County, Kansas Zone 6b July

This month in Rush County, Kansas

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Rush County, Kansas.

Avg. last frost April 24
Avg. first frost October 15
Soil temp (4") 83°F
Watering Moderate
Pest pressure High
Daylight 14.4 hrs
  1. Basket week: irises

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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Bearded Iris (Iris germanica) are among the most regal flowers of the late-spring garden, producing elegantly ruffled blooms in virtually every color of the rainbow — often in spectacular bicolor combinations. Named for the fuzzy "beard" on the lower falls (petals), bearded irises grow from thick horizontal rhizomes that spread to form dense clumps over time. Individual blooms last only a few days, but a well-established clump produces successive flowers over 3–4 weeks. Many are intensely fragrant. Native iris species including blue flag iris (I. versicolor) and Virginia iris (I. virginica) are excellent choices for wet or native garden settings.

Rush County, Kansas is in USDA Zone 6b. The average last spring frost is April 24 and the first fall frost is October 15, giving you a growing season of approximately 174 days.

At an elevation of 759 feet, Rush County receives approximately 21.7 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Irises during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Rush County, KS (Zone 6b) Moderate season
174 days
Last Spring Frost April 24
174 growing days
First Fall Frost October 15

Rush County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.3

Drainage

Well Drained

Irises Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Transplant: Apr 24 🌸 Bloom: Jun 19 – Jul 17
Recommended (50%) ✓ Fits season (83 days to spare)
Transplant: May 1 🌸 Bloom: Jun 26 – Jul 24
Safe Start (90%) ✓ Fits season (79 days to spare)
Transplant: May 18 🌸 Bloom: Jul 13 – Aug 10

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Rush County

How your county's soil matches Irises's growing requirements.

Soil pH

Your soil pH (6.4–7.3) overlaps with Irises's range (6.8–7.0), though not a perfect match.

Soil Texture

The loam soil in Rush County is excellent for Irises — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Irises.

How to Plant Irises

0.5"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Irises

3
successive plantings in your 174-day season

Sow every 6.9 weeks. Last sowing by Jul 07 to harvest before frost.

Irises Water Budget

Plant needs
0.5″/week
Rainfall provides
0.5″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Irises

Irises needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Irises Needs Rainfall You Supplement Action
Jan 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 2.2" 2.1" 0.1" 💧 Light watering
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 3.4" 0" ✅ Rainfall sufficient
Jul 2.2" 2.9" 0" ✅ Rainfall sufficient
Aug 2.2" 2.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.2" 1.5" 0.7" 💧 Light watering
Nov 0.7" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Rush County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Irises Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Irises needs ~1,160 GDD — county provides 2,523 GDD Excellent fit

Irises Planting Timeline — Rush County, KS

Irises Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 – May 15
Bloom June 26 Jun 26 – Jul 24

Plant 0.5" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Bloom
July Bloom
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6.8–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

174 days in Rush County

Growing Tips for Irises in Rush County

Direct sow Irises outdoors after April 24 in Rush County when soil has warmed and frost danger has passed.

Rush County receives only 22" of rain annually. Irises needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant rhizomes in late summer to early fall (July–September) after bloom season, setting them horizontally with the top of the rhizome at or just slightly below soil surface — never deeply buried. Full sun is essential for best bloom; at least 6 hours. Well-drained soil is critical; wet rhizomes rot in winter. After bloom, remove flower stalks but leave foliage until it browns in fall. Divide every 3–5 years in late summer when clumps become congested (crowded rhizomes stop blooming). Iris borer is the primary pest — remove and destroy affected fans. Year 2+ after division delivers the most bloom; freshly divided rhizomes may have limited or no bloom in their first season.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Irises in Rush County, KS?

Rush County is in Zone 6b with an average last frost of April 24. Plan your Irises planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rush County, KS?

Rush County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 24 and first fall frost is October 15.

When should I plant Irises in Rush County, KS?

In Rush County, KS, plant Irises after the last frost (around April 24) and before the first frost (around October 15). Best results when soil holds above 50°F.

What growing zone is Rush County, KS for Irises?

Rush County sits in USDA Zone 6b. Irises grows reliably in zones 3a through 9b, so it's a good fit here.

Can Irises grow in Rush County's climate?

Yes — Irises grows well in Rush County's temperate climate. Rush County averages a 174-day frost-free season, with last frost around April 24 and first frost around October 15.

🌱

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A 22-page printable planner built for Rush County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Rush County, KS. Local conditions may vary. Last updated: July 2026.

Sources & credits

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