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When to plant Irises in Smith County County,

Plant Irises in Smith County County during the brief April 30–May 14 window. With 174 frost-free days, fall plantings can't mature before October 14.

When to Plant Irises in Smith County, KS

Smith County, Kansas Zone 6a June

Your June gardening checklist

Each item below is timed to Smith County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 23
Avg. first frost October 14
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Basket week: irises

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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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.

Smith County, Kansas is in USDA Zone 6a. The average last spring frost is April 23 and the first fall frost is October 14, giving you a growing season of approximately 174 days.

At an elevation of 1,048 feet, Smith County receives approximately 26.2 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Irises to ensure they mature before fall.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Smith County, KS (Zone 6a) Moderate season
174 days
Last Spring Frost April 23
174 growing days
First Fall Frost October 14
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Smith County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.3

Drainage

Well Drained

Irises Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Transplant: Apr 24 🌸 Bloom: Jun 19 – Jul 17
Recommended (50%) ✓ Fits season (83 days to spare)
Transplant: Apr 30 🌸 Bloom: Jun 25 – Jul 23
Safe Start (90%) ✓ Fits season (78 days to spare)
Transplant: May 17 🌸 Bloom: Jul 12 – Aug 9

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 Smith County

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

Soil pH

Your soil pH (6.5–7.3) overlaps with Irises's range (6.8–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Irises.

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 06 to harvest before frost.

Irises Water Budget

Plant needs
0.5″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 33 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 0.7" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.2" 2.6" 0" ✅ Rainfall sufficient
May 2.2" 3.7" 0" ✅ Rainfall sufficient
Jun 2.2" 4.1" 0" ✅ Rainfall sufficient
Jul 2.2" 3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.4" 0" ✅ Rainfall sufficient
Sep 2.2" 2.3" 0" ✅ Rainfall sufficient
Oct 2.2" 1.9" 0.3" 💧 Light watering
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Smith 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 ~1,040 GDD — county provides 2,262 GDD Excellent fit

Irises Planting Timeline — Smith County, KS

Irises Planting Calendar

Activity When Date Range
Transplant Outdoors April 30 Apr 30 – May 14
Bloom June 25 Jun 25 – Jul 23

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
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6.8–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

174 days in Smith County

Growing Tips for Irises in Smith County

Direct sow Irises outdoors after April 23 in Smith County when soil has warmed and frost danger has passed.

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 Smith County, KS?

Smith County is in Zone 6a with an average last frost of April 23. Plan your Irises planting based on this frost date — see the calendar above for exact timing.

What planting zone is Smith County, KS?

Smith County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 23 and first fall frost is October 14.

When should I plant Irises in Smith County County, ?

In Smith County County, , plant Irises after the last frost (around April 23) and before the first frost (around October 14). Best results when soil holds above 50°F.

What growing zone is Smith County County, for Irises?

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

Can Irises grow in Smith County County's climate?

Yes — Irises grows well in Smith County County's temperate climate. Smith County County averages a 174-day frost-free season, with last frost around April 23 and first frost around October 14.

🌱

Your Smith County Garden Planner — Free

A 22-page printable planner built for Smith County (Zone 6a). 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 Smith 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.