When to Plant Amaranth in Linn County, OR
May in the garden — Linn County, Oregon
Here's what deserves your attention in Linn County, Oregon this month. Everything below is tailored to Zone 8b and timed around your local frost dates.
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Plant out amaranth
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
Before June arrives, get these ready
- Starting indoors: amaranth
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.
Linn County, Oregon is in USDA Zone 8b. The average last spring frost is April 22 and the first fall frost is October 25, giving you a growing season of approximately 186 days.
At an elevation of 259 feet, Linn County receives approximately 37.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Amaranth to ensure they mature before fall.
Linn County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.3
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 Linn County
How your county's soil matches Amaranth's growing requirements.
Soil pH
Your soil pH (5.6–6.3) is more acidic than Amaranth prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Linn County is excellent for Amaranth — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.4%) — Amaranth will thrive.
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 | — | 5.8" | 0" | ❄️ Dormant |
| Feb | — | 3.8" | 0" | ❄️ Dormant |
| Mar | — | 4.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| May | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jun | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Jul | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Aug | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Sep | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Oct | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Nov | — | 5.4" | 0" | ❄️ Dormant |
| Dec | — | 5.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Linn 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 — Linn County, OR
Amaranth Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | May 6 | May 6 – May 20 |
| Direct Sow | April 29 | Apr 29 – May 20 |
| Harvest | August 5 | Aug 5 – Sep 23 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| 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: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
186 days in Linn County
Growing Tips for Amaranth in Linn County
Direct sow Amaranth outdoors after April 22 in Linn 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 Linn County, OR?
Linn County is in Zone 8b with an average last frost of April 22. Plan your Amaranth planting based on this frost date — see the calendar above for exact timing.
What planting zone is Linn County, OR?
Linn County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 22 and first fall frost is October 25.
Your Linn County Garden Planner — Free
A 24-page printable planner built for Linn County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.