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When to plant Irises in Franklin County, KS

Plant Irises in Franklin County during the brief April 19–May 3 window. With 196 frost-free days, fall plantings can't mature before October 25.

When to Plant Irises in Franklin County, KS

Franklin County, Kansas Zone 6b June

June in Franklin County, Kansas — your action list

Your garden in Franklin County, Kansas is working on a schedule, even when you're not. Here's where you should be this June.

Avg. last frost April 12
Avg. first frost October 25
Soil temp (4") 75°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Bring in the irises

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Before July arrives, get these ready
  • First harvests: irises

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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.

Franklin County, Kansas is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.

At an elevation of 834 feet, Franklin County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Irises during the growing season.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Franklin County, KS (Zone 6b) Moderate season
196 days
Last Spring Frost April 12
196 growing days
First Fall Frost October 25

Franklin County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Irises Planting Risk Windows

Early Start (70% safe) ✓ Fits season (103 days to spare)
Transplant: Apr 13 🌸 Bloom: Jun 8 – Jul 6
Recommended (50%) ✓ Fits season (105 days to spare)
Transplant: Apr 19 🌸 Bloom: Jun 14 – Jul 12
Safe Start (90%) ✓ Fits season (107 days to spare)
Transplant: May 3 🌸 Bloom: Jun 28 – Jul 26

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 Franklin County

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

Soil pH

Your soil pH (6.3–7.2) is more acidic than Irises prefers (6.8–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Irises will thrive.

How to Plant Irises

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

Succession Planting Irises

3
successive plantings in your 196-day season

Sow every 6.9 weeks. Last sowing by Jul 17 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 6/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 2.2" 2.4" 0" ✅ Rainfall sufficient
May 2.2" 3.6" 0" ✅ Rainfall sufficient
Jun 2.2" 4.2" 0" ✅ Rainfall sufficient
Jul 2.2" 3.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3" 0" ✅ Rainfall sufficient
Sep 2.2" 2.2" 0" ✅ Rainfall sufficient
Oct 2.2" 1.5" 0.7" 💧 Light watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Franklin 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 ~1,100 GDD — county provides 2,695 GDD Excellent fit

Irises Planting Timeline — Franklin County, KS

Irises Planting Calendar

Activity When Date Range
Transplant Outdoors April 19 Apr 19 – May 3
Bloom June 14 Jun 14 – Jul 12

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
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: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

196 days in Franklin County

Growing Tips for Irises in Franklin County

Direct sow Irises outdoors after April 12 in Franklin County when soil has warmed and frost danger has passed.

Franklin County receives only 24" 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 Franklin County, KS?

Franklin County is in Zone 6b with an average last frost of April 12. Plan your Irises planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, KS?

Franklin County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 25.

When should I plant Irises in Franklin County, KS?

In Franklin County, KS, plant Irises after the last frost (around April 12) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Franklin County, KS for Irises?

Franklin 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 Franklin County's climate?

Yes — Irises grows well in Franklin County's temperate climate. Franklin County averages a 196-day frost-free season, with last frost around April 12 and first frost around October 25.

🌱

Your Franklin County Garden Planner — Free

A 22-page printable planner built for Franklin 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 Franklin County, KS. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.