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When to plant Portulaca in Atchison County, MO

Atchison County's spring Portulaca window runs April 29 through May 20. time plantings around the expected last-frost window for best survival.

When to Plant Portulaca in Atchison County, MO

Atchison County, Missouri Zone 5b June

This month in Atchison County, Missouri

Here's what deserves your attention in Atchison County, Missouri this month. Everything below is tailored to Zone 5b and timed around your local frost dates.

Avg. last frost April 22
Avg. first frost October 13
Soil temp (4") 68°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Start harvesting portulaca

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to 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.

Atchison County, Missouri is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 13, giving you a growing season of approximately 174 days.

At an elevation of 1,206 feet, Atchison County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Portulaca to ensure they mature before fall.

Annual Blooms in Summer Pollinator-friendly Deer-resistant
Atchison County, MO (Zone 5b) Moderate season
174 days
Last Spring Frost April 22
174 growing days
First Fall Frost October 13

Atchison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Mar 11 Transplant: Apr 22 🌸 Bloom: Jun 10 – Sep 16
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jun 17 – Sep 23
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: Mar 31 Transplant: May 12 🌸 Bloom: Jun 30 – Oct 6

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 Atchison County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Portulaca's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Portulaca.

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

4
successive plantings in your 174-day season

Sow every 5.7 weeks. Last sowing by Aug 04 to harvest before frost.

Portulaca Water Budget

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

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 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 4.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4.2" 0" ✅ Rainfall sufficient
Aug 2.2" 4.3" 0" ✅ Rainfall sufficient
Sep 2.2" 4.1" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Atchison 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 ~735 GDD — county provides 2,131 GDD Excellent fit

Portulaca Planting Timeline — Atchison County, MO

Portulaca Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 29 Apr 29 – May 20
Bloom June 17 Jun 17 – Sep 23

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
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: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

174 days in Atchison County

Growing Tips for Portulaca in Atchison County

Direct sow Portulaca outdoors after April 22 in Atchison 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 Atchison County, MO?

Atchison County is in Zone 5b with an average last frost of April 22. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Atchison County, MO?

Atchison County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 13.

When should I plant Portulaca in Atchison County, MO?

In Atchison County, MO, plant Portulaca after the last frost (around April 22) and before the first frost (around October 13). Best results when soil holds above 50°F.

What growing zone is Atchison County, MO for Portulaca?

Atchison County sits in USDA Zone 5b. Portulaca grows reliably in zones 3a through 11b, so it's a good fit here.

Can Portulaca grow in Atchison County's climate?

Yes — Portulaca grows well in Atchison County's temperate climate. Atchison County averages a 174-day frost-free season, with last frost around April 22 and first frost around October 13.

🌱

Your Atchison County Garden Planner — Free

A 22-page printable planner built for Atchison County (Zone 5b). 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 Atchison County, MO. 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.