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When to Plant Salvia in Polk County, TX

Polk County, Texas Zone 9a July

July to-do list for Polk County, Texas

If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 4
Avg. first frost November 23
Soil temp (4") 89°F
Watering Low
Pest pressure High
Daylight 13.8 hrs
  1. Bring in the salvia

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this July that'll pay off in August
  • 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.

Polk County, Texas is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 23, giving you a growing season of approximately 264 days.

At an elevation of 292 feet, Polk County receives approximately 63 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Salvia may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Salvia will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Salvia root diseases.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting Fragrant
Polk County, TX (Zone 9a) Long season
264 days
Last Spring Frost March 4
264 growing days
First Fall Frost November 23

Polk County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6.6

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (50 days to spare)
Start indoors: Dec 25 Transplant: Jan 29 🌸 Bloom: Apr 9 – Sep 24
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Jan 7 Transplant: Feb 11 🌸 Bloom: Apr 22 – Oct 7
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Jan 31 Transplant: Mar 7 🌸 Bloom: May 16 – Oct 31

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 Polk County

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

Soil pH

Your soil pH (5.2–6.6) overlaps with Salvia's range (5.5–7.0), though not a perfect match.

Soil Texture

Sandy soil in Polk County warms quickly in spring but drains fast. Salvia will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Salvia.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Salvia.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

4
successive plantings in your 264-day season

Sow every 8 weeks. Last sowing by Aug 25 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 700 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 1.4" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 4.3" 4" 0.3" 💧 Light watering
Apr 4.3" 5.8" 0" ✅ Rainfall sufficient
May 4.3" 8.5" 0" ✅ Rainfall sufficient
Jun 4.3" 11.4" 0" ✅ Rainfall sufficient
Jul 4.3" 7" 0" ✅ Rainfall sufficient
Aug 4.3" 7.9" 0" ✅ Rainfall sufficient
Sep 4.3" 6.5" 0" ✅ Rainfall sufficient
Oct 4.3" 4.4" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Polk 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 ~1,760 GDD — county provides 5,808 GDD Excellent fit

Salvia Planting Timeline — Polk County, TX

Salvia Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors February 11 Feb 11 – Feb 25
Bloom April 22 Apr 22 – Oct 7

· 12" apart · Rows 18" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

264 days in Polk County

Growing Tips for Salvia in Polk County

Direct sow Salvia outdoors after March 04 in Polk County when soil has warmed and frost danger has passed.

Sandy soil in Polk County dries quickly — mulch Salvia with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 96°F in Polk County, provide afternoon shade for Salvia and water deeply in the morning.

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 Polk County, TX?

Polk County is in Zone 9a with an average last frost of March 4. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Polk County, TX?

Polk County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 23.

🌱

Your Polk County Garden Planner — Free

A 22-page printable planner built for Polk County (Zone 9a). 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 Polk County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

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