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When to Plant Tulips in Okanogan County, WA

Okanogan County, Washington Zone 6b July

Your July game plan for Okanogan County, Washington

Here's what deserves your attention in Okanogan County, Washington this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost May 13
Avg. first frost September 26
Soil temp (4") 65°F
Watering Critical
Pest pressure High
Daylight 15.5 hrs
To set up a strong August, finish these tasks
  • Fall sowing: tulips

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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.

Okanogan County, Washington is in USDA Zone 6b. The average last spring frost is May 13 and the first fall frost is September 26, giving you a growing season of approximately 136 days.

At an elevation of 3,788 feet, Okanogan County receives approximately 21.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Tulips to ensure they mature before fall.

Bulb Blooms in Spring Pollinator-friendly Good for cutting
Okanogan County, WA (Zone 6b) Short season
136 days
Last Spring Frost May 13
136 growing days
First Fall Frost September 26

Okanogan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Tulips Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 8 🌸 Bloom from: Apr 17
Recommended (50%) ✓ Fits season
Transplant: May 13 🌸 Bloom from: Apr 22
Safe Start (90%) ✓ Fits season
Transplant: Jun 6 🌸 Bloom from: May 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 Okanogan County

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

Soil pH

Your soil pH (5.4–6.5) is more acidic than Tulips prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Tulips.

Organic Matter

Organic matter is excellent (5.6%) — 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

11
successive plantings in your 136-day season

Sow every 1.7 weeks. Last sowing by Aug 27 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Tulips Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/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 2.9" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 2.2" 1.3" 0.9" 💧 Light watering
Jun 2.2" 0.7" 1.5" 🚿 Regular watering
Jul 2.2" 0.3" 1.9" 🚿 Regular watering
Aug 2.2" 0.4" 1.8" 🚿 Regular watering
Sep 2.2" 0.7" 1.5" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 3.6" 0" ❄️ Dormant
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Okanogan 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 ~276 GDD — county provides 1,666 GDD Excellent fit

Tulips Planting Timeline — Okanogan County, WA

Tulips Planting Calendar

Activity When Date Range
Bloom August 1 Aug 1 – Aug 29
Fall Sowing August 22 Aug 22 – Sep 5

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 Fall Sowing
October
November
December

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: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

136 days in Okanogan County

Growing Tips for Tulips in Okanogan County

Direct sow Tulips outdoors after May 13 in Okanogan County when soil has warmed and frost danger has passed.

Your generous 136.0-day season in Okanogan County allows multiple plantings of Tulips. Sow every 7.0 days for continuous harvest.

Okanogan County receives only 21" of rain annually. Tulips needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Okanogan County, WA?

Okanogan County is in Zone 6b with an average last frost of May 13. Plan your Tulips planting based on this frost date — see the calendar above for exact timing.

What planting zone is Okanogan County, WA?

Okanogan County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 13 and first fall frost is September 26.

🌱

Your Okanogan County Garden Planner — Free

A 22-page printable planner built for Okanogan County (Zone 6b). 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 Okanogan 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.