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When to Plant Irises in Fannin County, TX

Fannin County, Texas Zone 8a June

Your June gardening checklist

Welcome to June in Zone 8a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 16
Avg. first frost November 15
Soil temp (4") 80°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Basket week: 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.

Fannin County, Texas is in USDA Zone 8a. The average last spring frost is March 16 and the first fall frost is November 15, giving you a growing season of approximately 244 days.

At an elevation of 282 feet, Fannin County receives approximately 63.8 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Irises during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Irises root diseases.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Fannin County, TX (Zone 8a) Long season
244 days
Last Spring Frost March 16
244 growing days
First Fall Frost November 15
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Fannin County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Irises Planting Risk Windows

Early Start (70% safe) ✓ Fits season (163 days to spare)
Transplant: Mar 7 🌸 Bloom: Apr 25 – May 30
Recommended (50%) ✓ Fits season (160 days to spare)
Transplant: Mar 16 🌸 Bloom: May 4 – Jun 8
Safe Start (90%) ✓ Fits season (152 days to spare)
Transplant: Apr 9 🌸 Bloom: May 28 – Jul 2

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 Fannin County

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

Soil pH

Your soil pH (6.3–7.8) is more alkaline than Irises prefers (6.8–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Irises.

How to Plant Irises

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

Succession Planting Irises

4
successive plantings in your 244-day season

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

Irises Water Budget

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

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 1.4" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.2" 4.3" 0" ✅ Rainfall sufficient
Apr 2.2" 6.3" 0" ✅ Rainfall sufficient
May 2.2" 8.7" 0" ✅ Rainfall sufficient
Jun 2.2" 11.1" 0" ✅ Rainfall sufficient
Jul 2.2" 7.7" 0" ✅ Rainfall sufficient
Aug 2.2" 7.9" 0" ✅ Rainfall sufficient
Sep 2.2" 6.2" 0" ✅ Rainfall sufficient
Oct 2.2" 4.3" 0" ✅ Rainfall sufficient
Nov 2.2" 2.1" 0.1" 💧 Light watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Fannin 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 ~1,280 GDD — county provides 3,904 GDD Excellent fit

Irises Planting Timeline — Fannin County, TX

Irises Planting Calendar

Activity When Date Range
Transplant Outdoors March 16 Mar 16 – Mar 30
Bloom May 4 May 4 – Jun 8

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

244 days in Fannin County

Growing Tips for Irises in Fannin County

Direct sow Irises outdoors after March 16 in Fannin 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 Fannin County, TX?

Fannin County is in Zone 8a with an average last frost of March 16. Plan your Irises planting based on this frost date — see the calendar above for exact timing.

What planting zone is Fannin County, TX?

Fannin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 16 and first fall frost is November 15.

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Your Fannin County Garden Planner — Free

A 22-page printable planner built for Fannin County (Zone 8a). 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 Fannin County, TX. 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.