When to plant Daylily in St. Clair County, IL
In St. Clair County, Daylily is a single-season spring crop — there's no second fall window. Plant April 9–April 23 for an 60–90-day harvest, finishing well before the November 2 first frost.
When to Plant Daylily in St. Clair County, IL
July to-do list for St. Clair County, Illinois
Here's what deserves your attention in St. Clair County, Illinois this month. Everything below is tailored to Zone 7a and timed around your local frost dates.
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Start harvesting daylily
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
A few tasks this July that'll pay off in August
- First harvests: daylily
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.
St. Clair County, Illinois is in USDA Zone 7a. The average last spring frost is April 2 and the first fall frost is November 2, giving you a growing season of approximately 214 days.
At an elevation of 711 feet, St. Clair County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Daylily during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Daylily Planting Risk Windows
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 St. Clair County
How your county's soil matches Daylily's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Daylily's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Clair County is excellent for Daylily — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.1%) — Daylily will thrive.
How to Plant Daylily
Succession Planting Daylily
Sow every 6.9 weeks. Last sowing by Aug 04 to harvest before frost.
Daylily Water Budget
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.5" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in St. Clair 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 Planting Timeline — St. Clair County, IL
Daylily Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 29 | Jan 29 – Feb 12 |
| Transplant Outdoors | April 9 | Apr 9 – Apr 23 |
| Bloom | June 18 | Jun 18 – Oct 22 |
Plant 1" deep · 24" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| 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: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
214 days in St. Clair County
Growing Tips for Daylily in St. Clair County
Direct sow Daylily outdoors after April 02 in St. Clair 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 →
Daylily in Other Locations
Frequently Asked Questions
When should I plant Daylily in St. Clair County, IL?
St. Clair County is in Zone 7a with an average last frost of April 2. Plan your Daylily planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, IL?
St. Clair County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 2 and first fall frost is November 2.
When should I plant Daylily in St. Clair County, IL?
In St. Clair County, IL, plant Daylily after the last frost (around April 2) and before the first frost (around November 2). Best results when soil holds above 50°F.
What growing zone is St. Clair County, IL for Daylily?
St. Clair 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 St. Clair County's climate?
Yes — Daylily grows well in St. Clair County's temperate climate. St. Clair County averages a 214-day frost-free season, with last frost around April 2 and first frost around November 2.
Your St. Clair County Garden Planner — Free
A 22-page printable planner built for St. Clair 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.