When to plant Lilies in Warren County, IL
Plant Lilies in Warren County during the brief April 27–May 11 window. With 191 frost-free days, fall plantings can't mature before October 21.
When to Plant Lilies in Warren County, IL
July in Warren County, Illinois — your action list
Your Warren County, Illinois garden is entering a new phase. Here's what's on the schedule for July and why each task matters now.
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Bring in the lilies
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
A few tasks this July that'll pay off in August
- First harvests: lilies
Lilies (Lilium spp.) are among the most impressive summer-blooming bulbs, delivering bold, upward- or outward-facing trumpet blooms on tall stems from June through August. Asiatic hybrids are the most cold-hardy, earliest to bloom, and easiest to grow; Oriental hybrids bloom later with intensely fragrant, larger flowers. Orienpet (OT) hybrids combine the hardiness of Asiatics with the fragrance and size of Orientals. True lilies (not to be confused with daylilies, which are Hemerocallis) form scaly bulbs that persist and multiply underground, returning reliably each year with increasingly large clumps.
Warren County, Illinois is in USDA Zone 5b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 801 feet, Warren County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Lilies during the growing season.
Warren County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
Drainage
Well Drained
Lilies 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 Warren County
How your county's soil matches Lilies's growing requirements.
Soil pH
Your soil pH (5.9–6.8) overlaps with Lilies's range (6.0–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Warren County is excellent for Lilies — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Lilies will thrive.
How to Plant Lilies
Succession Planting Lilies
Sow every 8 weeks. Last sowing by Jun 23 to harvest before frost.
Lilies Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Lilies
Lilies needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Lilies Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 3" | 1.3" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Warren County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lilies 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.
Lilies Planting Timeline — Warren County, IL
Lilies Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 27 | Apr 27 – May 11 |
| Bloom | July 6 | Jul 6 – Oct 5 |
Plant 5" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| 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
1"/week · Only during dry spells
📅 Days to Maturity
70–120 days
🧪 Soil pH
Needs 6–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
191 days in Warren County
Growing Tips for Lilies in Warren County
Direct sow Lilies outdoors after April 13 in Warren County when soil has warmed and frost danger has passed.
General growing tips
Plant bulbs in fall (preferred, September–October) or spring, setting them 3 times their diameter deep (typically 4–6 inches) with the pointed end up. Lilies need excellent drainage — they will rot in wet or heavy clay soils. Site with full sun on stems and blooms but cool, shaded soil at the base (ground cover or shallow-rooted annuals at their feet is ideal). Remove spent blooms but leave stems and foliage until they yellow naturally, as the bulb needs the foliage to photosynthesize and rebuild energy stores. Red lily beetle is a serious pest in the Northeast and Pacific Northwest; inspect plants regularly and hand-pick adults and larvae. Never plant Oriental or Asiatic lilies near cats — all Lilium species are highly toxic to cats. Year 2+ bulbs produce the most stems and largest blooms.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lilies in Other Locations
Frequently Asked Questions
When should I plant Lilies in Warren County, IL?
Warren County is in Zone 5b with an average last frost of April 13. Plan your Lilies planting based on this frost date — see the calendar above for exact timing.
What planting zone is Warren County, IL?
Warren County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 13 and first fall frost is October 21.
When should I plant Lilies in Warren County, IL?
In Warren County, IL, plant Lilies after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.
What growing zone is Warren County, IL for Lilies?
Warren County sits in USDA Zone 5b. Lilies grows reliably in zones 3a through 9a, so it's a good fit here.
Can Lilies grow in Warren County's climate?
Yes — Lilies grows well in Warren County's temperate climate. Warren County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.
Your Warren County Garden Planner — Free
A 22-page printable planner built for Warren County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.