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When to Plant Portulaca in Mapleton, UT

Utah County, Utah Zone 7a August

August to-do list for Utah County, Utah

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

Avg. last frost May 5
Avg. first frost October 11
Soil temp (4") 66°F
Watering High
Pest pressure High
Daylight 13.6 hrs
  1. Bring in the portulaca

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in September — start thinking about
  • 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.

Mapleton, Utah is in USDA Zone 7a. The average last spring frost is May 5 and the first fall frost is October 11, giving you a growing season of approximately 159 days.

At an elevation of 5,535 feet, Utah County receives approximately 22.1 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Portulaca during the growing season.

Annual Blooms in Summer Pollinator-friendly Deer-resistant
Mapleton, UT (Zone 7a) Moderate season
159 days
Last Spring Frost May 5
159 growing days
First Fall Frost October 11

Mapleton Soil Profile

Soil Type

Loam

Soil pH

6.5-8.3

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 29 Transplant: Apr 26 🌸 Bloom: Jun 14 – Oct 11
Recommended (50%) ✗ May not fit
Start indoors: Apr 7 Transplant: May 5 🌸 Bloom: Jun 23 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: May 3 Transplant: May 31 🌸 Bloom: Jul 19 – Nov 15

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 Mapleton

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

Soil pH

Your soil pH (6.5–8.3) is more alkaline than Portulaca prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Utah 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

3
successive plantings in your 159-day season

Sow every 5.7 weeks. Last sowing by Aug 02 to harvest before frost.

Portulaca Water Budget

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

Water stress score is 8/10 — 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 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 2.2" 2.5" 0" ✅ Rainfall sufficient
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 1.8" 0.4" 💧 Light watering
Aug 2.2" 2.4" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 1.4" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Utah 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 ~870 GDD — county provides 2,305 GDD Excellent fit

Portulaca Planting Timeline — Mapleton, UT

Portulaca Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 5 May 5 – May 19
Direct Sow May 5 May 5 – May 26
Bloom June 23 Jun 23 – Oct 20

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
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 7a

📆 Growing Season

159 days in Utah County

Growing Tips for Portulaca in Mapleton

Direct sow Portulaca outdoors after May 05 in Utah County when soil has warmed and frost danger has passed.

Utah County receives only 22" of rain annually. Portulaca needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 →

🌱

Your Utah County Garden Planner — Free

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