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When to Plant Tulips in Asotin County, WA

Asotin County, Washington Zone 7a August

What to do in August

Each item below is timed to Asotin County, Washington's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 9
Avg. first frost September 30
Soil temp (4") 78°F
Watering Critical
Pest pressure High
Daylight 14 hrs
  1. Kick off the fall garden with tulips

    Your first frost is about 8 weeks away — plenty of time for these to mature.

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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.

Asotin County, Washington is in USDA Zone 7a. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.

At an elevation of 2,029 feet, Asotin County receives approximately 14 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Tulips during the growing season. With low rainfall, drip irrigation is essential for growing Tulips successfully. Mulch heavily to conserve soil moisture.

Bulb Blooms in Spring Pollinator-friendly Good for cutting
Asotin County, WA (Zone 7a) Short season
144 days
Last Spring Frost May 9
144 growing days
First Fall Frost September 30

Asotin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Tulips Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Transplant: Apr 28 🌸 Bloom: Apr 14 – May 5
Recommended (50%) ✓ Fits season (137 days to spare)
Transplant: May 9 🌸 Bloom: Apr 25 – May 16
Safe Start (90%) ✓ Fits season (130 days to spare)
Transplant: Jun 6 🌸 Bloom: May 23 – Jun 13

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 Asotin County

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

Soil pH

Your soil pH (5.5–6.5) overlaps with Tulips's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — 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 144-day season

Sow every 1.7 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Aug 26.

Tulips Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 117 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" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 0.9" 0" ❄️ Dormant
May 2.2" 0.8" 1.4" 🚿 Regular watering
Jun 2.2" 0.6" 1.6" 🚿 Regular watering
Jul 2.2" 0.2" 2" 🚿 Regular watering
Aug 2.2" 0.3" 1.9" 🚿 Regular watering
Sep 2.2" 0.5" 1.7" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Asotin 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 ~309 GDD — county provides 1,980 GDD Excellent fit

Tulips Planting Timeline — Asotin County, WA

Tulips Planting Calendar

Activity When Date Range
Bloom August 12 Aug 12 – Sep 2
Fall Sowing August 26 Aug 26 – Sep 9

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 Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Only during dry spells

📅 Days to Maturity

15–30 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

144 days in Asotin County

Growing Tips for Tulips in Asotin County

Direct sow Tulips outdoors after May 09 in Asotin County when soil has warmed and frost danger has passed.

Your generous 144.0-day season in Asotin County allows multiple plantings of Tulips. Sow every 7.0 days for continuous harvest.

Asotin County receives only 14" 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 Asotin County, WA?

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

What planting zone is Asotin County, WA?

Asotin County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is May 9 and first fall frost is September 30.

🌱

Your Asotin County Garden Planner — Free

A 22-page printable planner built for Asotin 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 Asotin County, WA. Local conditions may vary. Last updated: August 2026.

Sources & credits

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