When to Plant Hyssop in Kittitas County, WA
Hyssop is a semi-evergreen perennial herb with intense blue flower spikes that attract bees and butterflies. It has a minty, slightly bitter flavor used in liqueurs and teas.
Kittitas County, Washington is in USDA Zone 6a. The average last spring frost is May 7 and the first fall frost is October 2, giving you a growing season of approximately 148 days.
At an elevation of 2,468 feet, Kittitas County receives approximately 18.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Hyssop during the growing season. With low rainfall, drip irrigation is essential for growing Hyssop successfully. Mulch heavily to conserve soil moisture.
Kittitas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
Drainage
Well Drained
Plant Planting Risk Windows
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 Kittitas County
How your county's soil matches Hyssop's growing requirements.
Soil pH
Your soil pH (5.5–6.7) overlaps with Hyssop's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in Kittitas County is excellent for Hyssop — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Hyssop will thrive.
How to Plant Hyssop
Succession Planting Hyssop
Sow every 8 weeks. Last sowing by Jul 04 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Hyssop
Hyssop 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 | Hyssop Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.9" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 1.7" | 0" | ❄️ Dormant |
| May | 2.2" | 1.2" | 1" | 💧 Light watering |
| Jun | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Jul | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Aug | 2.2" | 0.4" | 1.8" | 🚿 Regular watering |
| Sep | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Oct | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Kittitas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Hyssop 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.
Hyssop Planting Timeline — Kittitas County, WA
Hyssop Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 14 | May 14 – May 28 |
| Harvest | July 23 | Jul 23 – Sep 24 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–8 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
148 days in Kittitas County
Growing Tips for Hyssop in Kittitas County
Direct sow Hyssop outdoors after May 07 in Kittitas County when soil has warmed and frost danger has passed.
Kittitas County receives only 19" of rain annually. Hyssop needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Start seeds indoors or direct sow in spring. Prune back in early spring to encourage bushy growth. Hyssop is drought-tolerant once established and thrives in poor soil.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Hyssop in Other Locations
Frequently Asked Questions
When should I plant Hyssop in Kittitas County, WA?
Kittitas County is in Zone 6a with an average last frost of May 7. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.
What planting zone is Kittitas County, WA?
Kittitas County, Washington is in USDA Hardiness Zone 6a. The average last spring frost is May 7 and first fall frost is October 2.
Plan Your Garden with Confidence
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