When to Plant Amaranth in Valley County, ID
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.
Valley County, Idaho is in USDA Zone 4b. The average last spring frost is June 18 and the first fall frost is September 3, giving you a growing season of approximately 77 days.
At an elevation of 7,884 feet, Valley County receives approximately 17.8 inches of rainfall annually with predominantly loam soil. Summer highs average 83°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.
Valley County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.4
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 Valley County
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (6.4–8.4) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Valley County is excellent for Amaranth — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Amaranth.
How to Plant Amaranth
Plant 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 | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.7" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | — | 2.1" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Jul | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Aug | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Sep | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Oct | — | 1.5" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Valley 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 — Valley County, ID
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 16 | Apr 16 – Apr 30 |
| Transplant Outdoors | July 9 | Jul 9 – Jul 23 |
| Direct Sow | July 2 | Jul 2 – Jul 23 |
| Harvest | October 8 | Oct 8 – Nov 26 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | — |
| June | — |
| July | Transplant Outdoors Direct Sow |
| August | — |
| September | — |
| October | Harvest |
| November | Harvest |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
77 days in Valley County
Growing Tips for Amaranth in Valley County
Direct sow Amaranth outdoors after June 18 in Valley County when soil has warmed and frost danger has passed.
Your 77.0-day growing season in Valley County is tight for Amaranth (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.
Valley County receives only 18" 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 Valley County, ID?
Valley County is in Zone 4b with an average last frost of June 18. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.
What planting zone is Valley County, ID?
Valley County, Idaho is in USDA Hardiness Zone 4b. The average last spring frost is June 18 and first fall frost is September 3.
Plan Your Garden with Confidence
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