When to Plant Amaranth in Yuma County, AZ
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.
Yuma County, Arizona is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 1, giving you a growing season of approximately 294 days.
At an elevation of 4,781 feet, Yuma County receives approximately 9.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Amaranth during the growing season. Sandy soil warms quickly in spring — great for early planting — but Amaranth will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Amaranth successfully. Mulch heavily to conserve soil moisture.
Yuma County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.9-8.4
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 Yuma County
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (6.9–8.4) is more alkaline than Amaranth prefers (6.0–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Yuma County warms quickly in spring but drains fast. Amaranth will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (0.8%). Add 2-3 inches of compost before planting Amaranth.
How to Plant Amaranth
Plant Water Budget
Water stress score is 10/10 — 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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Mar | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Apr | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| May | 4.3" | 0.2" | 4.1" | 🚿 Regular watering |
| Jun | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jul | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Oct | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Nov | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Dec | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Yuma 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 — Yuma County, AZ
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 30 | Dec 30 – Jan 13 |
| Transplant Outdoors | February 17 | Feb 17 – Mar 3 |
| Direct Sow | February 10 | Feb 10 – Mar 3 |
| Harvest | May 19 | May 19 – Jul 7 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| 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: too_alkaline
🗺️ USDA Zone
Zone 10a
📆 Growing Season
294 days in Yuma County
Growing Tips for Amaranth in Yuma County
Direct sow Amaranth outdoors after February 10 in Yuma County when soil has warmed and frost danger has passed.
Sandy soil in Yuma County dries quickly — mulch Amaranth with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Yuma County receives only 9" 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
Frequently Asked Questions
When should I plant Amaranth in Yuma County, AZ?
Yuma County is in Zone 10a with an average last frost of February 10. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.
What planting zone is Yuma County, AZ?
Yuma County, Arizona is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 1.
Plan Your Garden with Confidence
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