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When to plant Salvia in Broadwater County County,

In Broadwater County County, Salvia is a single-season spring crop — there's no second fall window. Plant May 27–June 10 for an 90-day harvest, finishing well before the September 20 first frost.

When to Plant Salvia in Broadwater County, MT

Broadwater County, Montana Zone 5a June

June to-do list for Broadwater County, Montana

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Broadwater County, Montana.

Avg. last frost May 20
Avg. first frost September 20
Soil temp (4") 40°F
Watering Critical
Pest pressure High
Daylight 15.6 hrs
July will be here before you know it — start on
  • 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.

Broadwater County, Montana is in USDA Zone 5a. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.

At an elevation of 7,806 feet, Broadwater County receives approximately 17.4 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Salvia to ensure they mature before fall. 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
Broadwater County, MT (Zone 5a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20

Broadwater County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.1

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 8 Transplant: May 17 🌸 Bloom: Jul 26 – Oct 18
Recommended (50%) ✗ May not fit
Start indoors: Mar 18 Transplant: May 27 🌸 Bloom: Aug 5 – Oct 28
Safe Start (90%) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 23 🌸 Bloom: Sep 1 – Nov 24

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 Broadwater County

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

Soil pH

Your soil pH (6.6–8.1) is more alkaline than Salvia prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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 533 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 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 1.6" 2.7" 🚿 Regular watering
Sep 4.3" 1.5" 2.8" 🚿 Regular watering
Oct 1.5" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Broadwater 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 ~980 GDD — county provides 1,506 GDD Excellent fit

Salvia Planting Timeline — Broadwater County, MT

Salvia Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors May 27 May 27 – Jun 10
Bloom August 5 Aug 5 – Oct 28

· 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
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 5a

📆 Growing Season

123 days in Broadwater County

Growing Tips for Salvia in Broadwater County

Direct sow Salvia outdoors after May 20 in Broadwater County when soil has warmed and frost danger has passed.

Broadwater County receives only 17" 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 Broadwater County, MT?

Broadwater County is in Zone 5a with an average last frost of May 20. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Broadwater County, MT?

Broadwater County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is May 20 and first fall frost is September 20.

When should I plant Salvia in Broadwater County County, ?

In Broadwater County County, , plant Salvia after the last frost (around May 20) and before the first frost (around September 20). Best results when soil holds above 50°F.

What growing zone is Broadwater County County, for Salvia?

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

Can Salvia grow in Broadwater County County's climate?

Yes — Salvia grows well in Broadwater County County's temperate climate. Broadwater County County averages a 123-day frost-free season, with last frost around May 20 and first frost around September 20.

🌱

Your Broadwater County Garden Planner — Free

A 22-page printable planner built for Broadwater County (Zone 5a). 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 Broadwater County, MT. Local conditions may vary. Last updated: June 2026.

Sources & credits

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