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When to Plant Tulips in Jefferson County, OR

Jefferson County, Oregon Zone 7a June

Your June planting checklist for Jefferson County, Oregon

June is a pivotal month for Jefferson County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.

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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Tulips (Tulipa spp.) are the quintessential spring bulb, producing their iconic cup-shaped blooms in virtually every color from pure white to near-black. Fall-planted and cold-dependent, they emerge in early spring before most other flowers, providing weeks of bold color at a time when gardens are just waking up. Hundreds of cultivars span early-, mid-, and late-season types, extending the display across six weeks when planted in succession.

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 Tulips to ensure they mature before fall.

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

Soil Type

Silt Loam

Soil pH

5.3-6.7

Drainage

Well Drained

Tulips Planting Risk Windows

Early Start (70% safe) ✓ Fits season (96 days to spare)
Transplant: May 30 🌸 Bloom: May 16 – Jun 6
Recommended (50%) ✓ Fits season (95 days to spare)
Transplant: Jun 9 🌸 Bloom: May 26 – Jun 16
Safe Start (90%) ✓ Fits season (99 days to spare)
Transplant: Jun 22 🌸 Bloom: Jun 8 – Jun 29

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 Tulips's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Tulips

8"
Planting Depth
5"
Between Plants
6"
Between Rows

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

Succession Planting Tulips

8
successive plantings in your 102-day season

Sow every 1.7 weeks. Last sowing by Aug 20 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Tulips 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 Tulips

Tulips 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 Tulips 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.

Tulips 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.

Tulips needs ~208 GDD — county provides 943 GDD Excellent fit

Tulips Planting Timeline — Jefferson County, OR

Tulips Planting Calendar

Activity When Date Range
Bloom August 1 Aug 1 – Aug 22
Fall Sowing August 15 Aug 15 – Aug 29

Plant 8" deep · 5" apart · Rows 6" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

15–30 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

102 days in Jefferson County

Growing Tips for Tulips in Jefferson County

Direct sow Tulips 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 Tulips. Sow every 7.0 days for continuous harvest.

General growing tips

Plant bulbs pointed-end up in fall, 6–8 inches deep and 4–6 inches apart, in well-drained soil. Tulips require 12–16 weeks of cold at 35–45°F for proper vernalization — they fail to bloom without it. In zones 7–8b, plant bulbs a few weeks later than further north (late November) to ensure cold-soil uptake before spring warmth. Lift and discard bulbs after bloom in zones 7b+, as heat prevents reliable repeat flowering; treat them as annuals. Allow foliage to die back naturally before removing — it feeds next year's bulb (if leaving in the ground). Do not overwater; excellent drainage is essential to prevent bulb rot. Zones 9+: outdoor culture is not recommended; pre-chilling in the refrigerator is required and results are inconsistent.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tulips in Jefferson County, OR?

Jefferson County is in Zone 7a with an average last frost of June 9. Plan your Tulips 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.