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When to Plant Daffodils in Jefferson County, OR

Jefferson County, Oregon Zone 7a June

June in Jefferson County, Oregon — your action list

A quick June briefing for Jefferson County, Oregon gardeners — what's urgent, what's next, and what can wait.

Avg. last frost June 9
Avg. first frost September 19
Soil temp (4") 74°F
Watering High
Pest pressure High
Daylight 15.4 hrs

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Daffodils (Narcissus spp.) are among the most dependable and longest-lived of all spring bulbs. Their cheerful yellow and white blooms emerge in early spring, often while frost is still possible, bringing color weeks before most other flowers. Unlike tulips, established clumps naturalize readily — spreading and returning reliably year after year without replanting. Deer and rodents avoid them due to toxic alkaloids in the bulb and sap, making them a low-maintenance choice for naturalized areas, woodland edges, and mixed borders.

Jefferson County, Oregon is in USDA Zone 7a. The average last spring frost is June 9 and the first fall frost is September 19, giving you a growing season of approximately 102 days.

At an elevation of 21 feet, Jefferson County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Daffodils to ensure they mature before fall.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Jefferson County, OR (Zone 7a) Short season
102 days
Last Spring Frost June 9
102 growing days
First Fall Frost September 19

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.7

Drainage

Well Drained

Daffodils Planting Risk Windows

Early Start (70% safe) ✓ Fits season (110 days to spare)
Transplant: May 30 🌸 Bloom: May 2 – May 23
Recommended (50%) ✓ Fits season (109 days to spare)
Transplant: Jun 9 🌸 Bloom: May 12 – Jun 2
Safe Start (90%) ✓ Fits season (113 days to spare)
Transplant: Jun 22 🌸 Bloom: May 25 – Jun 15

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 Jefferson County

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

Soil pH

Your soil pH (5.3–6.7) overlaps with Daffodils's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — Daffodils will thrive.

How to Plant Daffodils

7"
Planting Depth
7"
Between Plants
8"
Between Rows

Fall planting: Sow 5 weeks before your first frost date for a fall harvest.

Succession Planting Daffodils

6
successive plantings in your 102-day season

Sow every 2.3 weeks. Last sowing by Aug 10 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Daffodils Water Budget

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

Monthly Watering Guide for Daffodils

Daffodils 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 Daffodils Needs Rainfall You Supplement Action
Jan 4.8" 0" ❄️ Dormant
Feb 3.7" 0" ❄️ Dormant
Mar 3.7" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 1.8" 0" ❄️ Dormant
Jun 2.2" 1.6" 0.6" 💧 Light watering
Jul 2.2" 0.5" 1.7" 🚿 Regular watering
Aug 2.2" 0.6" 1.6" 🚿 Regular watering
Sep 2.2" 1.6" 0.6" 💧 Light watering
Oct 3.2" 0" ❄️ Dormant
Nov 6.1" 0" ❄️ Dormant
Dec 5.5" 0" ❄️ Dormant

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

Daffodils 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.

Daffodils needs ~278 GDD — county provides 943 GDD Excellent fit

Daffodils Planting Timeline — Jefferson County, OR

Daffodils Planting Calendar

Activity When Date Range
Bloom July 18 Jul 18 – Aug 8
Fall Sowing August 15 Aug 15 – Aug 29

Plant 7" deep · 7" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June
July Bloom
August Fall Sowing Bloom
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

20–40 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

102 days in Jefferson County

Growing Tips for Daffodils in Jefferson County

Direct sow Daffodils outdoors after June 09 in Jefferson County when soil has warmed and frost danger has passed.

Your generous 102.0-day season in Jefferson County allows multiple plantings of Daffodils. Sow every 10.0 days for continuous harvest.

Common pests for Daffodils in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant bulbs pointed-end up in fall, 6–8 inches deep and 6–8 inches apart in well-drained soil. Allow 12–16 weeks of cold dormancy for proper vernalization. Do not cut back foliage until it turns yellow (6–8 weeks after bloom) — the dying leaves photosynthesize energy into the bulb for next year. Lift and divide overcrowded clumps every 4–5 years in summer after foliage dies back. In zones 7b–9b, select heat-tolerant cultivars (Jonquilla, Tazetta, and Cyclamineus divisions) that perform better with less chill than large-cupped types. Zones 10+: insufficient winter cold; pre-chilling is required but results inconsistent — not recommended for outdoor culture.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Daffodils in Jefferson County, OR?

Jefferson County is in Zone 7a with an average last frost of June 9. Plan your Daffodils planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, OR?

Jefferson County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is June 9 and first fall frost is September 19.

🌱

Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson 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.

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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 Jefferson 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.