When to Plant Cress in San Mateo County, CA
Garden cress is one of the fastest-growing edibles, producing peppery sprouts in as little as two weeks. It is excellent for microgreens and garnishes.
San Mateo County, California is in USDA Zone 10a. The average last spring frost is January 18 and the first fall frost is December 12, giving you a growing season of approximately 328 days.
At an elevation of 277 feet, San Mateo County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Cress to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cress successfully. Mulch heavily to conserve soil moisture.
San Mateo County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
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.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Cress Planting Timeline — San Mateo County, CA
Cress Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 21 | Dec 21 – Jan 4 |
| Transplant Outdoors | January 18 | Jan 18 – Feb 1 |
| Direct Sow | December 28 | Dec 28 – Jan 18 |
| Fall Sowing | October 17 | Oct 17 – Oct 31 |
| Harvest | February 1 | Feb 1 – Feb 22 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Transplant Outdoors Harvest |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | Start Indoors Direct Sow |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
14–21 days
Soil pH
6 – 7
USDA Zone
Zone 10a
Growing Season
328 days
Growing Tips for San Mateo County
Sow seeds thickly on moist soil or paper towels. Keep moist and harvest when 2-3 inches tall. Succession sow every few days for continuous supply. Grows well indoors year-round.
Companion Planting
Good Companions
Level Up Your Garden
Cress in Other Locations
Frequently Asked Questions
When should I plant Cress in San Mateo County, CA?
San Mateo County is in Zone 10a with an average last frost of January 18. Plan your Cress planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Mateo County, CA?
San Mateo County, California is in USDA Hardiness Zone 10a. The average last spring frost is January 18 and first fall frost is December 12.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help San Mateo County gardeners in Zone 10a organize planting dates, track what's growing, and never miss a planting window.
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