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When to Plant Salvia in Grant County, WA

Grant County, Washington Zone 7a August

August in Grant County, Washington — your action list

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

Avg. last frost April 29
Avg. first frost October 10
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Basket week: salvia

    If you can't use it all right away, check the food-preservation section of your planner.

Get ahead of 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.

Grant County, Washington is in USDA Zone 7a. The average last spring frost is April 29 and the first fall frost is October 10, giving you a growing season of approximately 164 days.

At an elevation of 3,122 feet, Grant County receives approximately 17.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°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
Grant County, WA (Zone 7a) Moderate season
164 days
Last Spring Frost April 29
164 growing days
First Fall Frost October 10

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 17 Transplant: Apr 14 🌸 Bloom: Jun 23 – Oct 13
Recommended (50%) ✗ May not fit
Start indoors: Mar 4 Transplant: Apr 29 🌸 Bloom: Jul 8 – Oct 28
Safe Start (90%) ✗ May not fit
Start indoors: Mar 24 Transplant: May 19 🌸 Bloom: Jul 28 – Nov 17

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 Grant County

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

Soil pH

Your soil pH (5.6–6.8) is within Salvia's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Salvia will thrive.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

2
successive plantings in your 164-day season

Sow every 8 weeks. Last sowing by Jul 12 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 802 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 2.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 1.5" 2.8" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 0.7" 3.6" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.6" 3.7" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Grant 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 ~1,460 GDD — county provides 2,993 GDD Excellent fit

Salvia Planting Timeline — Grant County, WA

Salvia Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors April 29 Apr 29 – May 13
Bloom July 8 Jul 8 – Oct 28

· 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors
May Transplant Outdoors
June
July Bloom
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: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

164 days in Grant County

Growing Tips for Salvia in Grant County

Direct sow Salvia outdoors after April 29 in Grant County when soil has warmed and frost danger has passed.

Grant 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 Grant County, WA?

Grant County is in Zone 7a with an average last frost of April 29. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, WA?

Grant County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 29 and first fall frost is October 10.

🌱

Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant County (Zone 7a). 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 Grant County, WA. 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.