When to Plant Hyssop in Lassen County, CA
May in Lassen County, California — your action list
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
June prep starts now
- Transplants going out: 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.
Lassen County, California is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 29, giving you a growing season of approximately 124 days.
At an elevation of 1,854 feet, Lassen County receives approximately 43.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Hyssop to ensure they mature before fall.
Lassen County Soil Profile
Soil Type
Loam
Soil pH
6.1-7.5
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 Lassen County
How your county's soil matches Hyssop's growing requirements.
Soil pH
Your soil pH (6.1–7.5) is within Hyssop's preferred range (6.0–8.0).
Soil Texture
The loam soil in Lassen County is excellent for Hyssop — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Hyssop.
How to Plant Hyssop
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 | — | 9.2" | 0" | ❄️ Dormant |
| Feb | — | 9.8" | 0" | ❄️ Dormant |
| Mar | — | 7.7" | 0" | ❄️ Dormant |
| Apr | — | 3.2" | 0" | ❄️ Dormant |
| May | 2.2" | 1" | 1.2" | 🚿 Regular watering |
| Jun | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jul | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Aug | 2.2" | 0" | 2.2" | 🚿 Regular watering |
| Sep | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 3.9" | 0" | ❄️ Dormant |
| Dec | — | 6.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lassen 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 — Lassen County, CA
Hyssop Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | June 4 | Jun 4 – Jun 18 |
| Harvest | August 13 | Aug 13 – Oct 15 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | Transplant Outdoors |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| 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: ideal
🗺️ USDA Zone
Zone 7a
📆 Growing Season
124 days in Lassen County
Growing Tips for Hyssop in Lassen County
Direct sow Hyssop outdoors after May 28 in Lassen 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 Lassen County, CA?
Lassen County is in Zone 7a with an average last frost of May 28. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lassen County, CA?
Lassen County, California is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 29.
Your Lassen County Garden Planner — Free
A 24-page printable planner built for Lassen 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.