When to Plant Amaranth in Buffalo County, SD
Your May gardening checklist
Welcome to May in Zone 4b. These are the moves that will have the biggest impact on your growing season.
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Move amaranth from tray to bed
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Put amaranth seeds straight in the ground
Your soil is 53°F — warm enough for these to germinate without babying.
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.
Buffalo County, South Dakota is in USDA Zone 4b. The average last spring frost is May 9 and the first fall frost is October 5, giving you a growing season of approximately 149 days.
At an elevation of 840 feet, Buffalo County receives approximately 23.7 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.
Buffalo County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.8
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 Buffalo County
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (6.5–7.8) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Buffalo 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 (3.5%). 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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Aug | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Sep | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Oct | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Buffalo 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 — Buffalo County, SD
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 7 | Mar 7 – Mar 21 |
| Transplant Outdoors | May 30 | May 30 – Jun 13 |
| Direct Sow | May 23 | May 23 – Jun 13 |
| Harvest | August 29 | Aug 29 – Oct 17 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| 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 · 1-2 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
149 days in Buffalo County
Growing Tips for Amaranth in Buffalo County
Direct sow Amaranth outdoors after May 09 in Buffalo County when soil has warmed and frost danger has passed.
Buffalo County receives only 24" 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 Buffalo County, SD?
Buffalo County is in Zone 4b with an average last frost of May 9. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.
What planting zone is Buffalo County, SD?
Buffalo County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 9 and first fall frost is October 5.
Your Buffalo County Garden Planner — Free
A 24-page printable planner built for Buffalo County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.