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When to Plant Salvia in Collin County, TX

Collin County, Texas Zone 8b July

July in the garden — Collin County, Texas

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

Avg. last frost March 10
Avg. first frost November 20
Soil temp (4") 89°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Pick salvia

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

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.

Collin County, Texas is in USDA Zone 8b. The average last spring frost is March 10 and the first fall frost is November 20, giving you a growing season of approximately 255 days.

At an elevation of 103 feet, Collin County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 94°F, providing good warmth for Salvia during the growing season. Clay soil retains moisture well for Salvia, but amend with compost to improve drainage and prevent root rot. 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
Collin County, TX (Zone 8b) Long season
255 days
Last Spring Frost March 10
255 growing days
First Fall Frost November 20

Collin County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.8

Drainage

Well Drained

Salvia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (44 days to spare)
Start indoors: Jan 5 Transplant: Feb 16 🌸 Bloom: Apr 27 – Sep 28
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Jan 13 Transplant: Feb 24 🌸 Bloom: May 5 – Oct 6
Safe Start (90%) ✓ Fits season (30 days to spare)
Start indoors: Feb 14 Transplant: Mar 28 🌸 Bloom: Jun 6 – Nov 7

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 Collin County

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

Soil pH

Your soil pH (7.3–7.8) is more alkaline than Salvia prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (43% clay) in Collin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Salvia.

How to Plant Salvia

12"
Between Plants
18"
Between Rows

Succession Planting Salvia

4
successive plantings in your 255-day season

Sow every 8 weeks. Last sowing by Aug 22 to harvest before frost.

Salvia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 1.8" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 6.9" 0" ✅ Rainfall sufficient
May 4.3" 10.2" 0" ✅ Rainfall sufficient
Jun 4.3" 9.9" 0" ✅ Rainfall sufficient
Jul 4.3" 7.3" 0" ✅ Rainfall sufficient
Aug 4.3" 8.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.5" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 2.2" 2.1" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Collin 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 ~1,640 GDD — county provides 5,227 GDD Excellent fit

Salvia Planting Timeline — Collin County, TX

Salvia Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors February 24 Feb 24 – Mar 10
Bloom May 5 May 5 – Oct 6

· 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors
March Transplant Outdoors
April
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 · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

255 days in Collin County

Growing Tips for Salvia in Collin County

Direct sow Salvia outdoors after March 10 in Collin County when soil has warmed and frost danger has passed.

With Collin County's clay soil (43% clay), work in 3-4 inches of compost before planting Salvia. Avoid tilling when soil is wet to prevent compaction.

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 Collin County, TX?

Collin County is in Zone 8b with an average last frost of March 10. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Collin County, TX?

Collin County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 10 and first fall frost is November 20.

🌱

Your Collin County Garden Planner — Free

A 22-page printable planner built for Collin County (Zone 8b). 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 Collin County, TX. Local conditions may vary. Last updated: July 2026.

Sources & credits

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