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When to Plant Lobelia in Curry County, OR

Curry County, Oregon Zone 9b July

This month in Curry County, Oregon

Here's what deserves your attention in Curry County, Oregon this month. Everything below is tailored to Zone 9b and timed around your local frost dates.

Avg. last frost March 21
Avg. first frost November 21
Soil temp (4") 93°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs

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Lobelia (Lobelia erinus) is a cool-season annual prized for the intense cobalt blue that is rare among bedding flowers. It blooms most prolifically in spring and early summer but stalls or dies back during heat peaks above 90°F. In zones 3–7 it delivers a long display; in zones 8–9 it is best treated as a spring annual that fades by midsummer. Trailing types cascade beautifully from containers and window boxes.

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 Lobelia during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lobelia root diseases.

Annual Blooms in Spring Pollinator-friendly
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

Lobelia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (219 days to spare)
Start indoors: Jan 3 Transplant: Dec 27 🌸 Bloom: Feb 21 – Mar 21
Recommended (50%) ✓ Fits season (224 days to spare)
Start indoors: Jan 24 Transplant: Jan 17 🌸 Bloom: Mar 14 – Apr 11
Safe Start (90%) ✓ Fits season (205 days to spare)
Start indoors: Mar 11 Transplant: Mar 4 🌸 Bloom: Apr 29 – May 27

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 Lobelia's growing requirements.

Soil pH

Your soil pH (5.7–6.7) overlaps with Lobelia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Lobelia

6"
Between Plants
8"
Between Rows

Succession Planting Lobelia

4
successive plantings in your 245-day season

Sow every 8 weeks. Last sowing by Sep 02 to harvest before frost.

Lobelia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 192 gal / 100 sq ft

Monthly Watering Guide for Lobelia

Lobelia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Lobelia Needs Rainfall You Supplement Action
Jan 8.2" 0" ❄️ Dormant
Feb 5.6" 0" ❄️ Dormant
Mar 4.3" 5.5" 0" ✅ Rainfall sufficient
Apr 4.3" 4.1" 0.2" 💧 Light watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 2.1" 2.2" 🚿 Regular watering
Jul 4.3" 0.8" 3.5" 🚿 Regular watering
Aug 4.3" 0.9" 3.4" 🚿 Regular watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 4.3" 4.6" 0" ✅ Rainfall sufficient
Nov 4.3" 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.

Lobelia 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.

Lobelia needs ~1,425 GDD — county provides 4,655 GDD Excellent fit

Lobelia Planting Timeline — Curry County, OR

Lobelia Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 – Feb 7
Transplant Outdoors January 17 Jan 17 – Jan 31
Bloom March 14 Mar 14 – Apr 11

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors
February Start Indoors
March Bloom
April Bloom
May
June
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–80 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

245 days in Curry County

Growing Tips for Lobelia in Curry County

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

General growing tips

Start seeds indoors 10–12 weeks before last frost — seed is dust-fine and requires light to germinate; surface-sow and press gently. Keep at 65–70°F. Not reliably direct-sown. Transplant in cool weather, 2–4 weeks before last frost date is acceptable in zones 5+. Shear plants by one-third after the first bloom flush to encourage a second flush in fall. Provide afternoon shade in zones 7+ to extend bloom into summer.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lobelia in Curry County, OR?

Curry County is in Zone 9b with an average last frost of March 21. Plan your Lobelia 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: July 2026.

Sources & credits

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