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When to Plant Zinnia in Curry County, OR

Curry County, Oregon Zone 9b June

This month in Curry County, Oregon

We've pulled the most time-sensitive tasks for Curry County, Oregon this June and put them front and centre. Tackle them in order.

Avg. last frost March 21
Avg. first frost November 21
Soil temp (4") 86°F
Watering High
Pest pressure High
Daylight 15.1 hrs
  1. Bring in the zinnia

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

To set up a strong July, finish these tasks
  • First harvests: zinnia

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Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.

Curry County, Oregon is in USDA Zone 9b. The average last spring frost is March 21 and the first fall frost is November 21, giving you a growing season of approximately 245 days.

At an elevation of 295 feet, Curry County receives approximately 53.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Zinnia during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Zinnia root diseases.

Annual Blooms in Summer Pollinator-friendly Deer-resistant Good for cutting
Curry County, OR (Zone 9b) Long season
245 days
Last Spring Frost March 21
245 growing days
First Fall Frost November 21

Curry County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Zinnia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (16 days to spare)
Start indoors: Jan 31 Transplant: Jan 31 🌸 Bloom: Apr 11 – Oct 10
Recommended (50%) ✓ Fits season (21 days to spare)
Start indoors: Feb 21 Transplant: Feb 21 🌸 Bloom: May 2 – Oct 31
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: Apr 8 Transplant: Apr 8 🌸 Bloom: Jun 17 – Dec 16

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 Curry County

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

Soil pH

Your soil pH (5.7–6.7) is within Zinnia's preferred range (5.5–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.4%) — Zinnia will thrive.

How to Plant Zinnia

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Zinnia

4
successive plantings in your 245-day season

Sow every 6.9 weeks. Last sowing by Sep 12 to harvest before frost.

Zinnia Water Budget

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

Monthly Watering Guide for Zinnia

Zinnia 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 Zinnia Needs Rainfall You Supplement Action
Jan 8.2" 0" ❄️ Dormant
Feb 5.6" 0" ❄️ Dormant
Mar 2.2" 5.5" 0" ✅ Rainfall sufficient
Apr 2.2" 4.1" 0" ✅ Rainfall sufficient
May 2.2" 3.4" 0" ✅ Rainfall sufficient
Jun 2.2" 2.1" 0.1" 💧 Light watering
Jul 2.2" 0.8" 1.4" 🚿 Regular watering
Aug 2.2" 0.9" 1.3" 🚿 Regular watering
Sep 2.2" 2" 0.2" 💧 Light watering
Oct 2.2" 4.6" 0" ✅ Rainfall sufficient
Nov 2.2" 8.1" 0" ✅ Rainfall sufficient
Dec 7.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Curry County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Zinnia 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.

Zinnia needs ~1,235 GDD — county provides 4,655 GDD Excellent fit

Zinnia Planting Timeline — Curry County, OR

Zinnia Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 – Mar 7
Transplant Outdoors February 21 Feb 21 – Mar 7
Direct Sow February 21 Feb 21 – Mar 14
Bloom May 2 May 2 – Oct 31

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

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

60–70 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

245 days in Curry County

Growing Tips for Zinnia in Curry County

Direct sow Zinnia outdoors after March 21 in Curry County when soil has warmed and frost danger has passed.

Common pests for Zinnia in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct-sow after last frost when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Zinnia in Curry County, OR?

Curry County is in Zone 9b with an average last frost of March 21. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Curry County, OR?

Curry County, Oregon is in USDA Hardiness Zone 9b. The average last spring frost is March 21 and first fall frost is November 21.

🌱

Your Curry County Garden Planner — Free

A 22-page printable planner built for Curry County (Zone 9b). 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 Curry County, OR. 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.