When to plant Amaranth in Pacifica, CA
For Pacifica, gardeners: plant Amaranth January 18 through February 8 once soil reads 50°F.
When to Plant Amaranth in Pacifica, CA
Your June planting checklist for San Mateo County, California
If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.
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Harvest amaranth as they ripen
If you can't use it all right away, check the food-preservation section of your planner.
Amaranth is an ancient grain crop with edible leaves and seeds, rich in protein and micronutrients. It thrives in warm conditions and is drought-tolerant once established.
Pacifica, 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 Amaranth to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Amaranth successfully. Mulch heavily to conserve soil moisture.
Pacifica Soil Profile
Soil Type
Loam
Soil pH
6.8-7.2
Drainage
Well Drained
Amaranth 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 Pacifica
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (6.8–7.2) is within Amaranth's preferred range (6.0–7.5).
Soil Texture
The loam soil in San Mateo County is excellent for Amaranth — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Amaranth.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Amaranth.
How to Plant Amaranth
Amaranth Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Amaranth
Amaranth needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Amaranth Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Feb | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Mar | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Oct | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Nov | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Dec | 4.3" | 2.9" | 1.4" | 💧 Light watering |
Water needs are for active growing months only (Jan–Dec in San Mateo County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Amaranth 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.
Amaranth Planting Timeline — Pacifica, CA
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 7 | Dec 7 – Dec 21 |
| Transplant Outdoors | January 25 | Jan 25 – Feb 8 |
| Direct Sow | January 18 | Jan 18 – Feb 8 |
| Harvest | April 26 | Apr 26 – Jun 14 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Transplant Outdoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 10a
📆 Growing Season
328 days in San Mateo County
Growing Tips for Amaranth in Pacifica
Direct sow Amaranth outdoors after January 18 in San Mateo County when soil has warmed and frost danger has passed.
San Mateo County receives only 17" of rain annually. Amaranth needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Direct sow after last frost when soil is warm. Thin seedlings to 18 inches apart. Harvest leaves when young and tender; harvest seeds when flower heads begin to dry.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Amaranth in Other Locations
When should I plant Amaranth in Pacifica, CA?
In Pacifica, CA, plant Amaranth after the last frost (around January 18) and before the first frost (around December 12). Best results when soil holds above 50°F.
What growing zone is Pacifica, CA for Amaranth?
Pacifica sits in USDA Zone 10a. Amaranth grows reliably in zones 2a through 11b, so it's a good fit here.
Can Amaranth grow in Pacifica's climate?
Yes — Amaranth grows well in Pacifica's temperate climate. Pacifica averages a 329-day frost-free season, with last frost around January 18 and first frost around December 12.
Your San Mateo County Garden Planner — Free
A 22-page printable planner built for San Mateo County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.