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When to plant Salvia in Custer County, CO

Custer County's 125-day season only supports one Salvia planting per year. Sow between May 30 and June 13 for the best chance at full maturity before September 25.

When to Plant Salvia in Custer County, CO

Custer County, Colorado Zone 5b June

Your June gardening checklist

A quick June briefing for Custer County, Colorado gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 23
Avg. first frost September 25
Soil temp (4") 44°F
Watering Critical
Pest pressure High
Daylight 14.6 hrs
Before July arrives, get these ready
  • Starting indoors: salvia

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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.

Custer County, Colorado is in USDA Zone 5b. The average last spring frost is May 23 and the first fall frost is September 25, giving you a growing season of approximately 125 days.

At an elevation of 8,115 feet, Custer County receives approximately 18.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Salvia during the growing season. With low rainfall, drip irrigation is essential for growing Salvia successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Custer County, CO (Zone 5b) Short season
125 days
Last Spring Frost May 23
125 growing days
First Fall Frost September 25

Custer County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 9 Transplant: May 18 🌸 Bloom: Jul 27 – Oct 26
Recommended (50%) ✗ May not fit
Start indoors: Mar 21 Transplant: May 30 🌸 Bloom: Aug 8 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: Apr 13 Transplant: Jun 22 🌸 Bloom: Aug 31 – Nov 30

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 Custer County

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

Soil pH

Your soil pH (6.5–7.8) is more alkaline than Salvia prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Custer County is excellent for Salvia — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Salvia.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 523 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.2" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 4.3" 2.3" 2" 💧 Light watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.4" 2.9" 🚿 Regular watering
Aug 4.3" 2.1" 2.2" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Custer 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 needs ~1,160 GDD — county provides 1,812 GDD Excellent fit

Salvia Planting Timeline — Custer County, CO

Salvia Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors May 30 May 30 – Jun 13
Bloom August 8 Aug 8 – Nov 7

· 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

125 days in Custer County

Growing Tips for Salvia in Custer County

Direct sow Salvia outdoors after May 23 in Custer County when soil has warmed and frost danger has passed.

Custer County receives only 18" of rain annually. Salvia needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 →

Frequently Asked Questions

When should I plant Salvia in Custer County, CO?

Custer County is in Zone 5b with an average last frost of May 23. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Custer County, CO?

Custer County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 23 and first fall frost is September 25.

When should I plant Salvia in Custer County, CO?

In Custer County, CO, plant Salvia after the last frost (around May 23) and before the first frost (around September 25). Best results when soil holds above 50°F.

What growing zone is Custer County, CO for Salvia?

Custer County sits in USDA Zone 5b. Salvia grows reliably in zones 2a through 11b, so it's a good fit here.

Can Salvia grow in Custer County's climate?

Yes — Salvia grows well in Custer County's temperate climate. Custer County averages a 125-day frost-free season, with last frost around May 23 and first frost around September 25.

🌱

Your Custer County Garden Planner — Free

A 22-page printable planner built for Custer 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.

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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 Custer County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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