Blog

When to Plant Portulaca in Chelan County, WA

Chelan County, Washington Zone 7a July

Your July game plan for Chelan County, Washington

Here's what deserves your attention in Chelan County, Washington this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 24
Avg. first frost October 20
Soil temp (4") 72°F
Watering Critical
Pest pressure High
Daylight 15.4 hrs
  1. Harvest portulaca as they ripen

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

Get ahead of August
  • First harvests: portulaca

Instant PDF download. No spam, unsubscribe any time.

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.

Chelan County, Washington is in USDA Zone 7a. The average last spring frost is April 24 and the first fall frost is October 20, giving you a growing season of approximately 179 days.

At an elevation of 3,517 feet, Chelan County receives approximately 14.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Portulaca during the growing season. With low rainfall, drip irrigation is essential for growing Portulaca successfully. Mulch heavily to conserve soil moisture.

Annual Blooms in Summer Pollinator-friendly Deer-resistant
Chelan County, WA (Zone 7a) Moderate season
179 days
Last Spring Frost April 24
179 growing days
First Fall Frost October 20

Chelan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Portulaca Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 16 Transplant: Apr 13 🌸 Bloom: Jun 1 – Sep 28
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 27 Transplant: Apr 24 🌸 Bloom: Jun 12 – Oct 9
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: Apr 21 Transplant: May 19 🌸 Bloom: Jul 7 – Nov 3

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 Chelan County

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

Soil pH

Your soil pH (5.5–6.3) is within Portulaca's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.1%) — Portulaca will thrive.

How to Plant Portulaca

8"
Between Plants
10"
Between Rows

Succession Planting Portulaca

4
successive plantings in your 179-day season

Sow every 5.7 weeks. Last sowing by Aug 11 to harvest before frost.

Portulaca Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 319 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 2.1" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 2.2" 1.2" 1" 💧 Light watering
May 2.2" 0.9" 1.3" 🚿 Regular watering
Jun 2.2" 0.6" 1.6" 🚿 Regular watering
Jul 2.2" 0.2" 2" 🚿 Regular watering
Aug 2.2" 0.3" 1.9" 🚿 Regular watering
Sep 2.2" 0.5" 1.7" 🚿 Regular watering
Oct 2.2" 1.2" 1" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Chelan 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 ~915 GDD — county provides 2,729 GDD Excellent fit

Portulaca Planting Timeline — Chelan County, WA

Portulaca Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 24 Apr 24 – May 15
Bloom June 12 Jun 12 – Oct 9

· 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 Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

179 days in Chelan County

Growing Tips for Portulaca in Chelan County

Direct sow Portulaca outdoors after April 24 in Chelan County when soil has warmed and frost danger has passed.

Chelan County receives only 14" 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 Chelan County, WA?

Chelan County is in Zone 7a with an average last frost of April 24. Plan your Portulaca planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chelan County, WA?

Chelan County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 24 and first fall frost is October 20.

🌱

Your Chelan County Garden Planner — Free

A 22-page printable planner built for Chelan 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Chelan County, WA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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