When to Plant Lemon Balm in Santa Clara County, CA
This month in Santa Clara County, California
Here's what deserves your attention in Santa Clara County, California this month. Everything below is tailored to Zone 9b and timed around your local frost dates.
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Start harvesting lemon balm
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
Before June arrives, get these ready
- First harvests: lemon balm
Lemon balm is a vigorous perennial herb with bright green, lemon-scented leaves. It makes a refreshing tea and is easy to grow but can spread aggressively.
Santa Clara County, California is in USDA Zone 9b. The average last spring frost is February 19 and the first fall frost is December 3, giving you a growing season of approximately 287 days.
At an elevation of 455 feet, Santa Clara County receives approximately 15.5 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Lemon Balm during the growing season. With low rainfall, drip irrigation is essential for growing Lemon Balm successfully. Mulch heavily to conserve soil moisture.
Santa Clara County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
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 Santa Clara County
How your county's soil matches Lemon Balm's growing requirements.
Soil pH
Your soil pH (6.7–7.8) overlaps with Lemon Balm's range (5.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Santa Clara County is excellent for Lemon Balm — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Lemon Balm.
How to Plant Lemon Balm
Succession Planting Lemon Balm
Sow every 6.9 weeks. Last sowing by Sep 24 to harvest before frost.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Lemon Balm
Lemon Balm 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 | Lemon Balm Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.2" | 0" | ❄️ Dormant |
| Feb | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Mar | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 1.1" | 1.1" | 🚿 Regular watering |
| May | 2.2" | 0.3" | 1.9" | 🚿 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" | 0.1" | 2.1" | 🚿 Regular watering |
| Oct | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| Nov | 2.2" | 1.4" | 0.8" | 💧 Light watering |
| Dec | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in Santa Clara County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lemon Balm 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.
Lemon Balm Planting Timeline — Santa Clara County, CA
Lemon Balm Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 26 | Feb 26 – Mar 12 |
| Harvest | April 30 | Apr 30 – Jun 18 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
60–70 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
287 days in Santa Clara County
Growing Tips for Lemon Balm in Santa Clara County
Direct sow Lemon Balm outdoors after February 19 in Santa Clara County when soil has warmed and frost danger has passed.
General growing tips
Start from seed, cuttings, or divisions. Contain in pots or use barriers to prevent spreading. Harvest frequently to keep plants bushy and prevent flowering.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lemon Balm in Other Locations
Frequently Asked Questions
When should I plant Lemon Balm in Santa Clara County, CA?
Santa Clara County is in Zone 9b with an average last frost of February 19. Plan your Lemon Balm planting based on this frost date — see the calendar above for exact timing.
What planting zone is Santa Clara County, CA?
Santa Clara County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 19 and first fall frost is December 3.
Your Santa Clara County Garden Planner — Free
A 24-page printable planner built for Santa Clara 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.