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When to plant Portulaca in Linn County County,

Plant Portulaca in Linn County County from April 16 to May 7 in spring. Linn County County sits in USDA Zone 6b, with last frost around April 9 and first frost on October 25.

When to Plant Portulaca in Linn County, KS

Linn County, Kansas Zone 6b June

June to-do list for Linn County, Kansas

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

Avg. last frost April 9
Avg. first frost October 25
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.6 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.

Before July arrives, get these ready
  • 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.

Linn County, Kansas is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 25, giving you a growing season of approximately 199 days.

At an elevation of 434 feet, Linn County receives approximately 33 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
Linn County, KS (Zone 6b) Moderate season
199 days
Last Spring Frost April 9
199 growing days
First Fall Frost October 25

Linn County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✓ Fits season (28 days to spare)
Start indoors: Feb 28 Transplant: Apr 11 🌸 Bloom: May 30 – Sep 19
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Mar 5 Transplant: Apr 16 🌸 Bloom: Jun 4 – Sep 24
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🌸 Bloom: Jun 17 – Oct 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 Linn County

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

Soil pH

Your soil pH (6.6–7.2) overlaps with Portulaca's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Portulaca.

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

4
successive plantings in your 199-day season

Sow every 5.7 weeks. Last sowing by Aug 16 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 0.9" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 3.5" 0" ✅ Rainfall sufficient
May 2.2" 5.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 4.2" 0" ✅ Rainfall sufficient
Aug 2.2" 4.5" 0" ✅ Rainfall sufficient
Sep 2.2" 2.6" 0" ✅ Rainfall sufficient
Oct 2.2" 2.3" 0" ✅ Rainfall sufficient
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Linn 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 2,885 GDD Excellent fit

Portulaca Planting Timeline — Linn County, KS

Portulaca Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 16 Apr 16 – May 7
Bloom June 4 Jun 4 – Sep 24

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

📆 Growing Season

199 days in Linn County

Growing Tips for Portulaca in Linn County

Direct sow Portulaca outdoors after April 09 in Linn 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 Linn County, KS?

Linn County is in Zone 6b with an average last frost of April 9. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Linn County, KS?

Linn County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 25.

When should I plant Portulaca in Linn County County, ?

In Linn County County, , plant Portulaca after the last frost (around April 9) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Linn County County, for Portulaca?

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

Can Portulaca grow in Linn County County's climate?

Yes — Portulaca grows well in Linn County County's temperate climate. Linn County County averages a 199-day frost-free season, with last frost around April 9 and first frost around October 25.

🌱

Your Linn County Garden Planner — Free

A 22-page printable planner built for Linn County (Zone 6b). 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 Linn County, KS. 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.