When to Plant Hyssop in Colusa County, CA
May in Colusa County, California — your action list
Here's what deserves your attention in Colusa County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.
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It's harvest week for hyssop
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Coming up in June — start thinking about
- First harvests: hyssop
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.
Colusa County, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.
At an elevation of 112 feet, Colusa County receives approximately 29.8 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Hyssop during the growing season.
Colusa County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.5
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 Colusa County
How your county's soil matches Hyssop's growing requirements.
Soil pH
Your soil pH (6.6–7.5) is within Hyssop's preferred range (6.0–8.0).
Soil Texture
The loam soil in Colusa County is excellent for Hyssop — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Hyssop.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Hyssop.
How to Plant Hyssop
Succession Planting Hyssop
Sow every 8 weeks. Last sowing by Aug 30 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 6.2" | 0" | ❄️ Dormant |
| Feb | — | 6.7" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.7" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2" | 0.2" | 💧 Light watering |
| May | 2.2" | 0.7" | 1.5" | 🚿 Regular watering |
| Jun | 2.2" | 0.1" | 2.1" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Oct | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| Nov | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 4.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Colusa 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 — Colusa County, CA
Hyssop Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | March 13 | Mar 13 – Mar 27 |
| Harvest | May 22 | May 22 – Jul 24 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Transplant Outdoors |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–8 · Your soil: ideal
🗺️ USDA Zone
Zone 9b
📆 Growing Season
267 days in Colusa County
Growing Tips for Hyssop in Colusa County
Direct sow Hyssop outdoors after March 06 in Colusa County when soil has warmed and frost danger has passed.
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 Colusa County, CA?
Colusa County is in Zone 9b with an average last frost of March 6. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.
What planting zone is Colusa County, CA?
Colusa County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 6 and first fall frost is November 28.
Your Colusa County Garden Planner — Free
A 24-page printable planner built for Colusa County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.