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When to plant Daylily in Union County County,

Plant Daylily in Union County County during the brief April 17–May 1 window. With 194 frost-free days, fall plantings can't mature before October 21.

When to Plant Daylily in Union County, IL

Union County, Illinois Zone 7a June

June in the garden — Union County, Illinois

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Union County, Illinois.

Avg. last frost April 10
Avg. first frost October 21
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Indoor seed-starting week for daylily

    You're about 18 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Basket week: daylily

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

July will be here before you know it — start on
  • First harvests: daylily

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Hemerocallis (Daylily) is one of the most adaptable and trouble-free perennials in cultivation. Though each flower lasts only a single day, established clumps produce dozens to hundreds of buds per stem, delivering weeks of continuous color through summer. Modern hybrids extend the range from pale cream and melon through deep burgundy and purple. Nearly indestructible once established — tolerating poor soil, drought, competition, and neglect — daylilies form dense spreading clumps that effectively suppress weeds. An excellent low-maintenance choice for slopes, borders, and naturalized areas.

Union County, Illinois is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.

At an elevation of 1,017 feet, Union County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Daylily during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Union County, IL (Zone 7a) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21
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Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.1

Drainage

Well Drained

Daylily Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 1 Transplant: Apr 12 🌸 Bloom: Jun 21 – Oct 25
Recommended (50%) ✗ May not fit
Start indoors: Feb 6 Transplant: Apr 17 🌸 Bloom: Jun 26 – Oct 30
Safe Start (90%) ✗ May not fit
Start indoors: Feb 20 Transplant: May 1 🌸 Bloom: Jul 10 – Nov 13

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 Union County

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

Soil pH

Your soil pH (5.8–7.1) overlaps with Daylily's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Union County is excellent for Daylily — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.4%) — Daylily will thrive.

How to Plant Daylily

1"
Planting Depth
24"
Between Plants
30"
Between Rows

Succession Planting Daylily

3
successive plantings in your 194-day season

Sow every 6.9 weeks. Last sowing by Jul 23 to harvest before frost.

Daylily Water Budget

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

Monthly Watering Guide for Daylily

Daylily 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 Daylily Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 4.5" 0" ✅ Rainfall sufficient
Jun 2.2" 4" 0" ✅ Rainfall sufficient
Jul 2.2" 3.9" 0" ✅ Rainfall sufficient
Aug 2.2" 3.6" 0" ✅ Rainfall sufficient
Sep 2.2" 3.2" 0" ✅ Rainfall sufficient
Oct 2.2" 2.4" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

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

Daylily 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.

Daylily needs ~1,200 GDD — county provides 3,104 GDD Excellent fit

Daylily Planting Timeline — Union County, IL

Daylily Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors April 17 Apr 17 – May 1
Bloom June 26 Jun 26 – Oct 30

Plant 1" deep · 24" apart · Rows 30" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in Union County

Growing Tips for Daylily in Union County

Direct sow Daylily outdoors after April 10 in Union County when soil has warmed and frost danger has passed.

General growing tips

Daylilies are most commonly propagated by division rather than seed; cultivar seeds do not come true. Transplant bare-root or potted divisions in early spring or fall, setting crowns no more than 1 inch below soil level. If starting from seed (species types only), start indoors 8–10 weeks before last frost. Established plants are extremely drought-tolerant; moderate water during bloom period improves flower quality. Divide crowded clumps every 3–5 years in early spring or fall to maintain vigor. In warm zones (8+), some cultivars are evergreen; in cold zones, foliage dies back each fall. Year 2+ plants bloom most heavily — first-year transplants may produce limited flowers.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Daylily in Union County, IL?

Union County is in Zone 7a with an average last frost of April 10. Plan your Daylily planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, IL?

Union County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 21.

When should I plant Daylily in Union County County, ?

In Union County County, , plant Daylily after the last frost (around April 10) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Union County County, for Daylily?

Union County County sits in USDA Zone 7a. Daylily grows reliably in zones 3a through 10b, so it's a good fit here.

Can Daylily grow in Union County County's climate?

Yes — Daylily grows well in Union County County's temperate climate. Union County County averages a 194-day frost-free season, with last frost around April 10 and first frost around October 21.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 7a). 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 Union County, IL. 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.