When to plant Salvia in St. Clair County, MO
St. Clair County's 201-day season only supports one Salvia planting per year. Sow between April 8 and April 22 for the best chance at full maturity before October 26.
When to Plant Salvia in St. Clair County, MO
Your June gardening checklist
Each item below is timed to St. Clair County, Missouri's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Indoor seed-starting week for salvia
You're about 16 weeks out from your last frost — the perfect window to get these germinating indoors.
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Collect salvia at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Get ahead of July
- First harvests: salvia
Salvia splendens is a tender perennial from Brazil grown as a warm-season annual throughout the US. Its vivid, upright flower spikes in brilliant red, purple, and coral are irresistible to hummingbirds, bees, and butterflies. One of the longest-blooming annuals in the landscape — plants bloom from early summer until hard frost with minimal deadheading required.
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 Salvia during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
Drainage
Well Drained
Salvia 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 Salvia's growing requirements.
Soil pH
Your soil pH (5.5–6.7) is within Salvia's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in St. Clair County is excellent for Salvia — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Salvia.
Organic Matter
Organic matter is moderate (2.9%). Annual compost additions will help Salvia.
How to Plant Salvia
Succession Planting Salvia
Sow every 8 weeks. Last sowing by Jul 28 to harvest before frost.
Salvia Water Budget
Monthly Watering Guide for Salvia
Salvia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Salvia 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.
Salvia 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.
Salvia Planting Timeline — St. Clair County, MO
Salvia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 4 | Feb 4 – Feb 18 |
| Transplant Outdoors | April 8 | Apr 8 – Apr 22 |
| Bloom | June 17 | Jun 17 – Sep 30 |
· 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| 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
70–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 6b
📆 Growing Season
201 days in St. Clair County
Growing Tips for Salvia in St. Clair County
Direct sow Salvia outdoors after April 08 in St. Clair County when soil has warmed and frost danger has passed.
General growing tips
Start indoors 8-10 weeks before last frost; seeds need 65-70°F soil and light to germinate (surface-sow, do not cover). Transplant after last frost when soil has warmed. Salvia is frost-sensitive — even a light frost kills plants. Pinch spent spikes to encourage continued bloom. Tolerates heat and humidity well once established. In zones 9b-11b can be grown as a short-lived perennial.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Salvia in Other Locations
Frequently Asked Questions
When should I plant Salvia in St. Clair County, MO?
St. Clair County is in Zone 6b with an average last frost of April 8. Plan your Salvia 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 Salvia in St. Clair County, MO?
In St. Clair County, MO, plant Salvia 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 Salvia?
St. Clair County sits in USDA Zone 6b. Salvia grows reliably in zones 2a through 11b, so it's a good fit here.
Can Salvia grow in St. Clair County's climate?
Yes — Salvia 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.