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When to plant Lilies in St. Clair County, MO

St. Clair County's 201-day season only supports one Lilies planting per year. Sow between April 15 and April 29 for the best chance at full maturity before October 26.

When to Plant Lilies in St. Clair County, MO

St. Clair County, Missouri Zone 6b June

Your June planting checklist for St. Clair County, Missouri

Welcome to June in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 8
Avg. first frost October 26
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Start harvesting lilies

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

Get ahead of July
  • First harvests: lilies

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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.

St. Clair County, Missouri is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.

At an elevation of 699 feet, St. Clair County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Lilies during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
St. Clair County, MO (Zone 6b) Long season
201 days
Last Spring Frost April 8
201 growing days
First Fall Frost October 26

St. Clair County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Lilies Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Transplant: Apr 8 🌸 Bloom: Jun 17 – Sep 23
Recommended (50%) ✓ Fits season (26 days to spare)
Transplant: Apr 15 🌸 Bloom: Jun 24 – Sep 30
Safe Start (90%) ✓ Fits season (26 days to spare)
Transplant: Apr 26 🌸 Bloom: Jul 5 – Oct 11

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 Lilies's growing requirements.

Soil pH

Your soil pH (5.5–6.7) overlaps with Lilies's range (6.0–6.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Lilies.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Lilies.

How to Plant Lilies

5"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Lilies

3
successive plantings in your 201-day season

Sow every 8 weeks. Last sowing by Jun 28 to harvest before frost.

Lilies Water Budget

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

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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 5.2" 0" ✅ Rainfall sufficient
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in St. Clair 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 needs ~1,662 GDD — county provides 3,517 GDD Excellent fit

Lilies Planting Timeline — St. Clair County, MO

Lilies Planting Calendar

Activity When Date Range
Transplant Outdoors April 15 Apr 15 – Apr 29
Bloom June 24 Jun 24 – Sep 30

Plant 5" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 6–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

201 days in St. Clair County

Growing Tips for Lilies in St. Clair County

Direct sow Lilies outdoors after April 08 in St. Clair 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 →

Frequently Asked Questions

When should I plant Lilies in St. Clair County, MO?

St. Clair County is in Zone 6b with an average last frost of April 8. Plan your Lilies planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Clair County, MO?

St. Clair County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 26.

When should I plant Lilies in St. Clair County, MO?

In St. Clair County, MO, plant Lilies after the last frost (around April 8) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is St. Clair County, MO for Lilies?

St. Clair County sits in USDA Zone 6b. Lilies grows reliably in zones 3a through 9a, so it's a good fit here.

Can Lilies grow in St. Clair County's climate?

Yes — Lilies grows well in St. Clair County's temperate climate. St. Clair County averages a 201-day frost-free season, with last frost around April 8 and first frost around October 26.

🌱

Your St. Clair County Garden Planner — Free

A 22-page printable planner built for St. Clair 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 St. Clair County, MO. 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.