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When to plant Portulaca in Minidoka County County,

Plant Portulaca in Minidoka County County during the brief May 17–June 7 window. With 146 frost-free days, fall plantings can't mature before October 3.

When to Plant Portulaca in Minidoka County, ID

Minidoka County, Idaho Zone 6a June

June to-do list for Minidoka County, Idaho

Welcome to June in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 10
Avg. first frost October 3
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 15.1 hrs
  1. Start portulaca under lights

    Your window is short. These crops want several weeks of indoor growth before they go outside.

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

Minidoka County, Idaho is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 3, giving you a growing season of approximately 146 days.

At an elevation of 5,990 feet, Minidoka County receives approximately 22.3 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
Minidoka County, ID (Zone 6a) Short season
146 days
Last Spring Frost May 10
146 growing days
First Fall Frost October 3

Minidoka County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 27 Transplant: May 8 🌸 Bloom: Jun 26 – Oct 9
Recommended (50%) ✗ May not fit
Start indoors: Apr 5 Transplant: May 17 🌸 Bloom: Jul 5 – Oct 18
Safe Start (90%) ✗ May not fit
Start indoors: May 2 Transplant: Jun 13 🌸 Bloom: Aug 1 – Nov 14

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 Minidoka County

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

Soil pH

Your soil pH (6.6–7.8) is more alkaline than Portulaca prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Portulaca.

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

3
successive plantings in your 146-day season

Sow every 5.7 weeks. Last sowing by Jul 25 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 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 1.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 2.2" 2.5" 0" ✅ Rainfall sufficient
Jun 2.2" 1.4" 0.8" 💧 Light watering
Jul 2.2" 2" 0.2" 💧 Light watering
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.2" 1.7" 0.5" 💧 Light watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Minidoka 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 2,117 GDD Excellent fit

Portulaca Planting Timeline — Minidoka County, ID

Portulaca Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 17 May 17 – Jun 7
Bloom July 5 Jul 5 – Oct 18

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors
May Transplant Outdoors Direct Sow
June Direct Sow
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 6a

📆 Growing Season

146 days in Minidoka County

Growing Tips for Portulaca in Minidoka County

Direct sow Portulaca outdoors after May 10 in Minidoka County when soil has warmed and frost danger has passed.

Minidoka 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 →

Frequently Asked Questions

When should I plant Portulaca in Minidoka County, ID?

Minidoka County is in Zone 6a with an average last frost of May 10. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Minidoka County, ID?

Minidoka County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 3.

When should I plant Portulaca in Minidoka County County, ?

In Minidoka County County, , plant Portulaca after the last frost (around May 10) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Minidoka County County, for Portulaca?

Minidoka County County sits in USDA Zone 6a. Portulaca grows reliably in zones 3a through 11b, so it's a good fit here.

Can Portulaca grow in Minidoka County County's climate?

Yes — Portulaca grows well in Minidoka County County's temperate climate. Minidoka County County averages a 146-day frost-free season, with last frost around May 10 and first frost around October 3.

🌱

Your Minidoka County Garden Planner — Free

A 22-page printable planner built for Minidoka County (Zone 6a). 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 Minidoka County, ID. 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.