Blog

When to plant Amaranth in Captiva, FL

The best window to plant Amaranth in Captiva, is January 28–February 18, when soil warms to 50°F. Last frost typically hits January 28; first frost December 19.

When to Plant Amaranth in Captiva, FL

Lee County, Florida Zone 10b July

What to do in July

Each item below is timed to Lee County, Florida's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost January 28
Avg. first frost December 19
Soil temp (4") 95°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Plan the fall garden

    Make a planting map for August. Tomatoes, peppers, brassicas, lettuce, root crops all go in over the next 8 weeks. Soil amendments and irrigation prep happen now.

  2. Keep heat-survivor crops productive

    Daily harvest of okra and southern peas keeps plants producing. Let pods over-mature and the plant stops setting new fruit.

  3. Watch for hurricane prep season

    August-October is hurricane season. Stake young trees, secure rain barrels, and plan how to protect tender transplants from high winds.

Instant PDF download. No spam, unsubscribe any time.

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.

Captiva, Florida is in USDA Zone 10b. The average last spring frost is January 28 and the first fall frost is December 19, giving you a growing season of approximately 325 days.

At an elevation of 408 feet, Lee County receives approximately 61.6 inches of rainfall annually with predominantly sand soil. Summer highs average 86°F, providing good warmth for Amaranth during the growing season. Sandy soil warms quickly in spring — great for early planting — but Amaranth will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Amaranth root diseases.

Captiva, FL (Zone 10b) Year-round
325 days
Last Spring Frost January 28
325 growing days
First Fall Frost December 19

Captiva Soil Profile

Soil Type

Sand

Soil pH

5.1-5.9

Drainage

Well Drained

Amaranth Planting Risk Windows

Early Start (70% safe) ✓ Fits season (176 days to spare)
Start indoors: Dec 8 Transplant: Jan 26 🍅 Harvest: Apr 27 – Jun 15
Recommended (50%) ✓ Fits season (178 days to spare)
Start indoors: Dec 17 Transplant: Feb 4 🍅 Harvest: May 6 – Jun 24
Safe Start (90%) ✓ Fits season (150 days to spare)
Start indoors: Jan 18 Transplant: Mar 8 🍅 Harvest: Jun 7 – Jul 26

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 Captiva

How your county's soil matches Amaranth's growing requirements.

Soil pH

Your soil pH (5.1–5.9) is more acidic than Amaranth prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Lee County warms quickly in spring but drains fast. Amaranth will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Amaranth.

Organic Matter

Organic matter is low (1.4%). Add 2-3 inches of compost before planting Amaranth.

How to Plant Amaranth

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Amaranth Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,469 gal / 100 sq ft

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 4.3" 3" 1.3" 💧 Light watering
Feb 4.3" 3.3" 1" 💧 Light watering
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 2.8" 1.5" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 7.6" 0" ✅ Rainfall sufficient
Jul 4.3" 10" 0" ✅ Rainfall sufficient
Aug 4.3" 7.7" 0" ✅ Rainfall sufficient
Sep 4.3" 9.3" 0" ✅ Rainfall sufficient
Oct 4.3" 5.1" 0" ✅ Rainfall sufficient
Nov 4.3" 2.7" 1.6" 💧 Light watering
Dec 4.3" 2.5" 1.8" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Lee 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 needs ~1,522 GDD — county provides 4,727 GDD Excellent fit

Amaranth Planting Timeline — Captiva, FL

Amaranth Planting Calendar

Activity When Date Range
Start Indoors December 17 Dec 17 – Dec 31
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow January 28 Jan 28 – Feb 18
Harvest May 6 May 6 – Jun 24

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Direct Sow
February Transplant Outdoors Direct Sow
March
April
May Harvest
June Harvest
July
August
September
October
November
December Start Indoors

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: too_acidic

🗺️ USDA Zone

Zone 10b

📆 Growing Season

325 days in Lee County

Growing Tips for Amaranth in Captiva

Direct sow Amaranth outdoors after January 28 in Lee County when soil has warmed and frost danger has passed.

Sandy soil in Lee County dries quickly — mulch Amaranth with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

  • Fennel

Check more plant combinations with our Companion Planting Checker →

When should I plant Amaranth in Captiva, FL?

In Captiva, FL, plant Amaranth after the last frost (around January 28) and before the first frost (around December 19). Best results when soil holds above 50°F.

What growing zone is Captiva, FL for Amaranth?

Captiva sits in USDA Zone 10b. Amaranth grows reliably in zones 2a through 11b, so it's a good fit here.

Can Amaranth grow in Captiva's climate?

Yes — Amaranth grows well in Captiva's temperate climate. Captiva averages a 326-day frost-free season, with last frost around January 28 and first frost around December 19.

🌱

Your Lee County Garden Planner — Free

A 22-page printable planner built for Lee County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lee County, FL. Local conditions may vary. Last updated: July 2026.