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When to Plant Portulaca in Webb County, TX

Webb County, Texas Zone 9b June

Top priorities for Webb County, Texas gardeners in June

Each item below is timed to Webb County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 9
Avg. first frost December 9
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Pick portulaca

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

July prep starts now
  • First harvests: portulaca

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Portulaca (Portulaca grandiflora), commonly called moss rose, is a succulent- stemmed annual built for hot, dry, low-fertility conditions where other flowers fail. Its silky, rose-like blooms open in full sun and close at night or on cloudy days. Excellent for slopes, rock gardens, containers, and parking-strip plantings where irrigation is limited. One of the easiest annuals for neglect- proof summer color.

Webb County, Texas is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 9, giving you a growing season of approximately 303 days.

At an elevation of 3,543 feet, Webb County receives approximately 50.9 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Portulaca may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Portulaca root diseases.

Annual Blooms in Summer Pollinator-friendly Deer-resistant
Webb County, TX (Zone 9b) Year-round
303 days
Last Spring Frost February 9
303 growing days
First Fall Frost December 9

Webb County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Dec 22 Transplant: Dec 29 🌸 Bloom: Feb 16 – Sep 7
Recommended (50%) ✓ Fits season (72 days to spare)
Start indoors: Jan 12 Transplant: Jan 19 🌸 Bloom: Mar 9 – Sep 28
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Feb 5 Transplant: Feb 12 🌸 Bloom: Apr 2 – Oct 22

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 Webb County

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

Soil pH

Your soil pH (6.6–7.7) is more alkaline than Portulaca prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

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

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

7
successive plantings in your 303-day season

Sow every 5.7 weeks. Last sowing by Sep 30 to harvest before frost.

Portulaca Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 Portulaca

Portulaca needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Portulaca Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 2.2" 1.9" 0.3" 💧 Light watering
Mar 2.2" 2.8" 0" ✅ Rainfall sufficient
Apr 2.2" 5" 0" ✅ Rainfall sufficient
May 2.2" 8.3" 0" ✅ Rainfall sufficient
Jun 2.2" 7.6" 0" ✅ Rainfall sufficient
Jul 2.2" 5.9" 0" ✅ Rainfall sufficient
Aug 2.2" 6.4" 0" ✅ Rainfall sufficient
Sep 2.2" 5.2" 0" ✅ Rainfall sufficient
Oct 2.2" 3.4" 0" ✅ Rainfall sufficient
Nov 2.2" 1.7" 0.5" 💧 Light watering
Dec 2.2" 1.5" 0.7" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Webb County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Portulaca 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.

Portulaca needs ~1,275 GDD — county provides 6,460 GDD Excellent fit

Portulaca Planting Timeline — Webb County, TX

Portulaca Planting Calendar

Activity When Date Range
Start Indoors January 12 Jan 12 – Jan 26
Transplant Outdoors January 19 Jan 19 – Feb 2
Direct Sow January 19 Jan 19 – Feb 9
Bloom March 9 Mar 9 – Sep 28

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

303 days in Webb County

Growing Tips for Portulaca in Webb County

Direct sow Portulaca outdoors after February 09 in Webb County when soil has warmed and frost danger has passed.

General growing tips

Direct-sow after last frost once soil warms to 65°F, or start indoors 4–6 weeks before last frost. Seed is tiny — surface sow and do not cover. Thin to proper spacing after germination. Thrives in poor, well-drained soil; rich or wet soil produces lush foliage but fewer blooms. No deadheading required — plants are self-cleaning. Double-flowered varieties hold blooms open longer in overcast conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Portulaca in Webb County, TX?

Webb County is in Zone 9b with an average last frost of February 9. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Webb County, TX?

Webb County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 9.

🌱

Your Webb County Garden Planner — Free

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

Sources & credits

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