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When to Plant Salvia in Malheur County, OR

Malheur County, Oregon Zone 6b August

What to do in August

August is a pivotal month for Malheur County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 18
Avg. first frost September 29
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 13.8 hrs
  1. Basket week: salvia

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

A few tasks this August that'll pay off in September
  • First harvests: 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.

Malheur County, Oregon is in USDA Zone 6b. The average last spring frost is May 18 and the first fall frost is September 29, giving you a growing season of approximately 134 days.

At an elevation of 2,676 feet, Malheur County receives approximately 17.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°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
Malheur County, OR (Zone 6b) Short season
134 days
Last Spring Frost May 18
134 growing days
First Fall Frost September 29

Malheur County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.3

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 27 Transplant: May 1 🌸 Bloom: Jul 10 – Oct 23
Recommended (50%) ✗ May not fit
Start indoors: Mar 16 Transplant: May 18 🌸 Bloom: Jul 27 – Nov 9
Safe Start (90%) ✗ May not fit
Start indoors: Apr 10 Transplant: Jun 12 🌸 Bloom: Aug 21 – Dec 4

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 Malheur County

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

Soil pH

Your soil pH (5.4–6.3) overlaps with Salvia's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Salvia.

Organic Matter

Organic matter is excellent (5.6%) — Salvia will thrive.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

2
successive plantings in your 134-day season

Sow every 8 weeks. Last sowing by Jul 01 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 896 gal / 100 sq ft

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 2.4" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 4.3" 0.9" 3.4" 🚿 Regular watering
Jun 4.3" 0.7" 3.6" 🚿 Regular watering
Jul 4.3" 0.3" 4" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 2.6" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Malheur 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 ~1,400 GDD — county provides 2,345 GDD Excellent fit

Salvia Planting Timeline — Malheur County, OR

Salvia Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors May 18 May 18 – Jun 1
Bloom July 27 Jul 27 – Nov 9

· 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

134 days in Malheur County

Growing Tips for Salvia in Malheur County

Direct sow Salvia outdoors after May 18 in Malheur County when soil has warmed and frost danger has passed.

Malheur 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 Malheur County, OR?

Malheur County is in Zone 6b with an average last frost of May 18. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Malheur County, OR?

Malheur County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is May 18 and first fall frost is September 29.

🌱

Your Malheur County Garden Planner — Free

A 22-page printable planner built for Malheur 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 Malheur County, OR. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.