When to Plant Amaranth in Floyd County, IA
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.
Floyd County, Iowa is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.
At an elevation of 714 feet, Floyd County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Amaranth to ensure they mature before fall.
Floyd County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.8
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 Floyd County
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (5.9–6.8) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Floyd County is excellent for Amaranth — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Amaranth.
How to Plant Amaranth
Plant Water Budget
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.6" | 0" | ❄️ Dormant |
| Apr | — | 3.1" | 0" | ❄️ Dormant |
| May | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Aug | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Sep | 4.3" | 3" | 1.3" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Floyd 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 — Floyd County, IA
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Harvest | August 21 | Aug 21 – Oct 9 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| 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
159 days in Floyd County
Growing Tips for Amaranth in Floyd County
Direct sow Amaranth outdoors after May 01 in Floyd County when soil has warmed and frost danger has passed.
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 Floyd County, IA?
Floyd County is in Zone 4b with an average last frost of May 1. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.
What planting zone is Floyd County, IA?
Floyd County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.
Plan Your Garden with Confidence
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