When to Plant Rosemary in Plumas County, CA
May in Plumas County, California — your action list
May is a pivotal month for Plumas County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Time to transplant rosemary
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.
Plumas County, California is in USDA Zone 7b. The average last spring frost is May 20 and the first fall frost is October 8, giving you a growing season of approximately 141 days.
At an elevation of 1,185 feet, Plumas County receives approximately 30.9 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Rosemary to ensure they mature before fall.
Plumas County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.6
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 Plumas County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (6.6–7.6) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Plumas County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Rosemary.
How to Plant Rosemary
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Rosemary
Rosemary needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.
| Month | Rosemary Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 6.9" | 0" | ❄️ Dormant |
| Feb | — | 6.2" | 0" | ❄️ Dormant |
| Mar | — | 5" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | 1.3" | 1" | 0.3" | 💧 Light watering |
| Jun | 1.3" | 0.2" | 1.1" | 🚿 Regular watering |
| Jul | 1.3" | 0" | 1.3" | 🚿 Regular watering |
| Aug | 1.3" | 0" | 1.3" | 🚿 Regular watering |
| Sep | 1.3" | 0.3" | 1" | 🚿 Regular watering |
| Oct | 1.3" | 1.2" | 0.1" | 💧 Light watering |
| Nov | — | 3" | 0" | ❄️ Dormant |
| Dec | — | 4.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Plumas County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rosemary 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.
Rosemary Planting Timeline — Plumas County, CA
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 27 | May 27 – Jun 10 |
| Harvest | August 19 | Aug 19 – Jan 6 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Harvest |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | Harvest |
| December | Harvest |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
80–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
141 days in Plumas County
Growing Tips for Rosemary in Plumas County
Direct sow Rosemary outdoors after May 20 in Plumas County when soil has warmed and frost danger has passed.
Your 141.0-day growing season in Plumas County is tight for Rosemary (80.0-180.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Rosemary in Other Locations
Frequently Asked Questions
When should I plant Rosemary in Plumas County, CA?
Plumas County is in Zone 7b with an average last frost of May 20. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Plumas County, CA?
Plumas County, California is in USDA Hardiness Zone 7b. The average last spring frost is May 20 and first fall frost is October 8.
Your Plumas County Garden Planner — Free
A 24-page printable planner built for Plumas County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.