When to Plant Amaranth in Robertson County, TX
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.
Robertson County, Texas is in USDA Zone 8a. The average last spring frost is March 7 and the first fall frost is November 16, giving you a growing season of approximately 254 days.
At an elevation of 85 feet, Robertson County receives approximately 61.1 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Amaranth during the growing season. Clay soil retains moisture well for Amaranth, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Amaranth root diseases.
Robertson County Soil Profile
Soil Type
Clay
Soil pH
6.8-8
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 Robertson County
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (6.8–8.0) overlaps with Amaranth's range (6.0–7.5), though not a perfect match.
Soil Texture
Heavy clay soil (45% clay) in Robertson County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (3.4%). Annual compost additions will help Amaranth.
How to Plant Amaranth
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 2.2" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 10" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 8.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 8.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.2" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Nov | 4.3" | 2.3" | 2" | 💧 Light watering |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Robertson 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 — Robertson County, TX
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 17 | Jan 17 – Jan 31 |
| Transplant Outdoors | March 21 | Mar 21 – Apr 4 |
| Direct Sow | March 14 | Mar 14 – Apr 4 |
| Harvest | June 20 | Jun 20 – Aug 8 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | — |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
254 days in Robertson County
Growing Tips for Amaranth in Robertson County
Direct sow Amaranth outdoors after March 07 in Robertson County when soil has warmed and frost danger has passed.
With Robertson County's clay soil (45% clay), work in 3-4 inches of compost before planting Amaranth. Avoid tilling when soil is wet to prevent compaction.
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 Robertson County, TX?
Robertson County is in Zone 8a with an average last frost of March 7. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.
What planting zone is Robertson County, TX?
Robertson County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 7 and first fall frost is November 16.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Robertson County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.