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When to plant Daylily in Clinton County, IL

Clinton County sits in cold Zone 6b. Plant Daylily April 17–May 1 for the single annual harvest; the October 19 first frost closes the window.

When to Plant Daylily in Clinton County, IL

Clinton County, Illinois Zone 6b June

Clinton County, Illinois gardeners: here's your June plan

June is a pivotal month for Clinton County, Illinois gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 10
Avg. first frost October 19
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Start daylily under lights

    These need a head start before your last frost (April 10). Sow into cells now so you're ready to transplant in a few weeks.

Coming up in July — start thinking about
  • 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.

Clinton County, Illinois is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 19, giving you a growing season of approximately 192 days.

At an elevation of 1,142 feet, Clinton County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Daylily during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting
Clinton County, IL (Zone 6b) Moderate season
192 days
Last Spring Frost April 10
192 growing days
First Fall Frost October 19

Clinton County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Daylily Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Jan 31 Transplant: Apr 11 🌸 Bloom: Jun 27 – Oct 17
Recommended (50%) ✗ May not fit
Start indoors: Feb 6 Transplant: Apr 17 🌸 Bloom: Jul 3 – Oct 23
Safe Start (90%) ✗ May not fit
Start indoors: Feb 15 Transplant: Apr 26 🌸 Bloom: Jul 12 – Nov 1

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 Clinton County

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

Soil pH

Your soil pH (6.0–7.0) is within Daylily's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — Daylily will thrive.

How to Plant Daylily

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

Succession Planting Daylily

3
successive plantings in your 192-day season

Sow every 6.9 weeks. Last sowing by Jul 21 to harvest before frost.

Daylily Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 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 1.6" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.3" 0" ✅ Rainfall sufficient
Jun 2.2" 4.9" 0" ✅ Rainfall sufficient
Jul 2.2" 4.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.9" 0" ✅ Rainfall sufficient
Sep 2.2" 3.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.2" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 1.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clinton 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 ~1,031 GDD — county provides 2,640 GDD Excellent fit

Daylily Planting Timeline — Clinton 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 July 3 Jul 3 – Oct 23

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
July Bloom
August Bloom
September Bloom
October Bloom
November
December

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: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Clinton County

Growing Tips for Daylily in Clinton County

Direct sow Daylily outdoors after April 10 in Clinton 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 Clinton County, IL?

Clinton County is in Zone 6b 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 Clinton County, IL?

Clinton County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 19.

When should I plant Daylily in Clinton County, IL?

In Clinton County, IL, plant Daylily after the last frost (around April 10) and before the first frost (around October 19). Best results when soil holds above 50°F.

What growing zone is Clinton County, IL for Daylily?

Clinton County sits in USDA Zone 6b. Daylily grows reliably in zones 3a through 10b, so it's a good fit here.

Can Daylily grow in Clinton County's climate?

Yes — Daylily grows well in Clinton County's temperate climate. Clinton County averages a 192-day frost-free season, with last frost around April 10 and first frost around October 19.

🌱

Your Clinton County Garden Planner — Free

A 22-page printable planner built for Clinton 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 Clinton 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.