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When to Plant Hyacinths in Clark County, WA

Clark County, Washington Zone 8b June

Your June planting checklist for Clark County, Washington

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Clark County, Washington.

Avg. last frost April 14
Avg. first frost October 27
Soil temp (4") 82°F
Watering High
Pest pressure High
Daylight 15.5 hrs

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Hyacinths (Hyacinthus orientalis) fill the spring garden with an almost overwhelming fragrance — a single cluster of blooms can perfume an entire yard. Dense, upright spikes of waxy florets in shades of purple, pink, blue, white, and red emerge in mid-spring, bridging the gap between the first crocus and the tulip peak. Though bulbs bloom most spectacularly in their first year, established plantings continue to produce graceful, less-dense flower spikes for several years. Deer and rabbits avoid them due to toxic alkaloids.

Clark County, Washington is in USDA Zone 8b. The average last spring frost is April 14 and the first fall frost is October 27, giving you a growing season of approximately 196 days.

At an elevation of 482 feet, Clark County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Hyacinths during the growing season.

Bulb Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting Fragrant
Clark County, WA (Zone 8b) Moderate season
196 days
Last Spring Frost April 14
196 growing days
First Fall Frost October 27
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Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.3

Drainage

Well Drained

Hyacinths Planting Risk Windows

Early Start (70% safe) ✓ Fits season (179 days to spare)
Transplant: Apr 8 🌸 Bloom: Apr 1 – Apr 22
Recommended (50%) ✓ Fits season (182 days to spare)
Transplant: Apr 14 🌸 Bloom: Apr 7 – Apr 28
Safe Start (90%) ✓ Fits season (180 days to spare)
Transplant: May 9 🌸 Bloom: May 2 – May 23

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 Clark County

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

Soil pH

Your soil pH (5.4–6.3) is more acidic than Hyacinths prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Hyacinths.

Organic Matter

Organic matter is excellent (4.8%) — Hyacinths will thrive.

How to Plant Hyacinths

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

Fall planting: Sow 4 weeks before your first frost date for a fall harvest.

Succession Planting Hyacinths

17
successive plantings in your 196-day season

Sow every 1.6 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Sep 29.

Hyacinths Water Budget

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

Monthly Watering Guide for Hyacinths

Hyacinths 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 Hyacinths Needs Rainfall You Supplement Action
Jan 5.4" 0" ❄️ Dormant
Feb 4.6" 0" ❄️ Dormant
Mar 4" 0" ❄️ Dormant
Apr 2.2" 2.6" 0" ✅ Rainfall sufficient
May 2.2" 2.5" 0" ✅ Rainfall sufficient
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 0.6" 1.6" 🚿 Regular watering
Aug 2.2" 0.8" 1.4" 🚿 Regular watering
Sep 2.2" 1.5" 0.7" 💧 Light watering
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 5.9" 0" ❄️ Dormant
Dec 7.2" 0" ❄️ Dormant

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

Hyacinths 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.

Hyacinths needs ~289 GDD — county provides 2,695 GDD Excellent fit

Hyacinths Planting Timeline — Clark County, WA

Hyacinths Planting Calendar

Activity When Date Range
Bloom September 22 Sep 22 – Oct 13
Fall Sowing September 29 Sep 29 – Oct 13

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

14–28 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

196 days in Clark County

Growing Tips for Hyacinths in Clark County

Direct sow Hyacinths outdoors after April 14 in Clark County when soil has warmed and frost danger has passed.

Your generous 196.0-day season in Clark County allows multiple plantings of Hyacinths. Sow every 7.0 days for continuous harvest.

General growing tips

Plant bulbs 6 inches deep and 6 inches apart in fall, when soil drops below 60°F. Wear gloves when handling — bulb sap causes contact dermatitis in some people. After bloom, deadhead the spent spike but leave the strap-like foliage until it yellows naturally. For naturalizing, plant at 6–8 inch spacings and allow clumps to mature undisturbed. In zones 7b–9b, treat bulbs as annuals or use pre-chilled stock; performance after year 1 declines in warm-winter zones. For forcing indoors, chill bulbs 10–12 weeks then bring into warmth.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hyacinths in Clark County, WA?

Clark County is in Zone 8b with an average last frost of April 14. Plan your Hyacinths planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, WA?

Clark County, Washington is in USDA Hardiness Zone 8b. The average last spring frost is April 14 and first fall frost is October 27.

🌱

Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 8b). 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 Clark County, WA. 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.