When to plant Comfrey in Saint Augustine, IL
Plant Comfrey in Saint Augustine during the brief April 24–May 8 window. With 181 frost-free days, fall plantings can't mature before October 15.
When to Plant Comfrey in Saint Augustine, IL
Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.
Saint Augustine, Illinois is in USDA Zone 5b. The average last spring frost is April 17 and the first fall frost is October 15, giving you a growing season of approximately 181 days.
At an elevation of 1,301 feet, Knox County receives approximately 33.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Comfrey to ensure they mature before fall.
Saint Augustine Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.8
Drainage
Well Drained
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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Jul | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Knox County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Comfrey Planting Timeline — Saint Augustine, IL
Comfrey Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Harvest | June 26 | Jun 26 – Sep 4 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
181 days in Knox County
Growing Tips for Saint Augustine
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 →
Comfrey in Other Locations
When should I plant Comfrey in Saint Augustine, IL?
In Saint Augustine, IL, plant Comfrey after the last frost (around April 17) and before the first frost (around October 15). Best results when soil holds above 50°F.
What growing zone is Saint Augustine, IL for Comfrey?
Saint Augustine sits in USDA Zone 5b. Comfrey grows reliably in zones 3a through 9b, so it's a good fit here.
Can Comfrey grow in Saint Augustine's climate?
Yes — Comfrey grows well in Saint Augustine's temperate climate. Saint Augustine averages a 181-day frost-free season, with last frost around April 17 and first frost around October 15.
Your Knox County Garden Planner — Free
A 22-page printable planner built for Knox County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.