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When to Plant Comfrey in Highlands County, FL

Highlands County, Florida Zone 9b May

Your May gardening checklist

We've pulled the most time-sensitive tasks for Highlands County, Florida this May and put them front and centre. Tackle them in order.

Avg. last frost January 29
Avg. first frost December 20
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Pick comfrey

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

A few tasks this May that'll pay off in June
  • First harvests: comfrey

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Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.

Highlands County, Florida is in USDA Zone 9b. The average last spring frost is January 29 and the first fall frost is December 20, giving you a growing season of approximately 325 days.

At an elevation of 111 feet, Highlands County receives approximately 57.6 inches of rainfall annually with predominantly sand soil. Summer highs average 95°F, so Comfrey may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Comfrey will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Comfrey root diseases.

Highlands County, FL (Zone 9b) Year-round
325 days
Last Spring Frost January 29
325 growing days
First Fall Frost December 20

Highlands County Soil Profile

Soil Type

Sand

Soil pH

4.9-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (181 days to spare)
Transplant: Jan 29 🍅 Harvest: Apr 2 – Jun 11
Recommended (50%) ✓ Fits season (185 days to spare)
Transplant: Feb 5 🍅 Harvest: Apr 9 – Jun 18
Safe Start (90%) ✓ Fits season (157 days to spare)
Transplant: Mar 9 🍅 Harvest: May 11 – Jul 20

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 Highlands County

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

Soil pH

Your soil pH (4.9–5.8) is more acidic than Comfrey prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Comfrey.

Organic Matter

Organic matter is low (1.6%). Add 2-3 inches of compost before planting Comfrey.

How to Plant Comfrey

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Comfrey

6
successive plantings in your 325-day season

Sow every 6.9 weeks. Last sowing by Sep 21 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,619 gal / 100 sq ft

Monthly Watering Guide for Comfrey

Comfrey needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Comfrey Needs Rainfall You Supplement Action
Jan 4.3" 2.4" 1.9" 💧 Light watering
Feb 4.3" 3.1" 1.2" 💧 Light watering
Mar 4.3" 3.6" 0.7" 💧 Light watering
Apr 4.3" 2.3" 2" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 8.5" 0" ✅ Rainfall sufficient
Jul 4.3" 7.5" 0" ✅ Rainfall sufficient
Aug 4.3" 9.1" 0" ✅ Rainfall sufficient
Sep 4.3" 8" 0" ✅ Rainfall sufficient
Oct 4.3" 5.1" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 4.3" 2.3" 2" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Highlands County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Comfrey 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.

Comfrey needs ~1,594 GDD — county provides 6,927 GDD Excellent fit

Comfrey Planting Timeline — Highlands County, FL

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors February 5 Feb 5 – Feb 19
Harvest April 9 Apr 9 – Jun 18

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

325 days in Highlands County

Growing Tips for Comfrey in Highlands County

Direct sow Comfrey outdoors after January 29 in Highlands County when soil has warmed and frost danger has passed.

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

General growing tips

Plant root cuttings 2 inches deep. Choose Bocking 14 variety to prevent self-seeding. Cut leaves 3-4 times per season for mulch or compost. Avoid planting near pathways as it spreads.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Comfrey in Highlands County, FL?

Highlands County is in Zone 9b with an average last frost of January 29. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Highlands County, FL?

Highlands County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is January 29 and first fall frost is December 20.

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Your Highlands County Garden Planner — Free

A 24-page printable planner built for Highlands County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.