When to plant Geraniums in Solano County County,
In Solano County County, Geraniums is a single-season spring crop — there's no second fall window. Plant January 12–January 26 for an 100-day harvest, finishing well before the December 3 first frost.
When to Plant Geraniums in Solano County, CA
Solano County, California gardeners: here's your June plan
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Solano County, California.
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It's harvest week for geraniums
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
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- First harvests: geraniums
Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.
Solano County, California is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 3, giving you a growing season of approximately 297 days.
At an elevation of 376 feet, Solano County receives approximately 40.4 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Geraniums may need afternoon shade and extra watering during peak heat.
Solano County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.3
Drainage
Well Drained
Geraniums 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 Solano County
How your county's soil matches Geraniums's growing requirements.
Soil pH
Your soil pH (6.8–7.3) is more alkaline than Geraniums prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Solano County is excellent for Geraniums — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Geraniums.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Geraniums.
How to Plant Geraniums
Succession Planting Geraniums
Sow every 8 weeks. Last sowing by Aug 25 to harvest before frost.
Geraniums Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Geraniums
Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Geraniums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.9" | 0" | ❄️ Dormant |
| Feb | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Mar | 4.3" | 6.6" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| May | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Jun | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Oct | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Nov | 4.3" | 3.3" | 1" | 💧 Light watering |
| Dec | 4.3" | 7.1" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Solano County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Geraniums 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.
Geraniums Planting Timeline — Solano County, CA
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 1 | Dec 1 – Dec 15 |
| Transplant Outdoors | January 12 | Jan 12 – Jan 26 |
| Bloom | March 23 | Mar 23 – Oct 5 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors |
| February | — |
| March | Bloom |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
297 days in Solano County
Growing Tips for Geraniums in Solano County
Direct sow Geraniums outdoors after February 09 in Solano County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Geraniums in Other Locations
Frequently Asked Questions
When should I plant Geraniums in Solano County, CA?
Solano County is in Zone 9b with an average last frost of February 9. Plan your Geraniums planting based on this frost date — see the calendar above for exact timing.
What planting zone is Solano County, CA?
Solano County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 3.
When should I plant Geraniums in Solano County County, ?
In Solano County County, , plant Geraniums after the last frost (around February 9) and before the first frost (around December 3). Best results when soil holds above 50°F.
What growing zone is Solano County County, for Geraniums?
Solano County County sits in USDA Zone 9b. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.
Can Geraniums grow in Solano County County's climate?
Yes — Geraniums grows well in Solano County County's temperate climate. Solano County County averages a 298-day frost-free season, with last frost around February 9 and first frost around December 3.
Your Solano County Garden Planner — Free
A 22-page printable planner built for Solano 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.