When to Plant Angelica in Knox County, IL
Your May game plan for Knox County, Illinois
We've pulled the most time-sensitive tasks for Knox County, Illinois this May and put them front and centre. Tackle them in order.
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Time to start angelica inside
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
Angelica is a dramatic biennial herb that can reach 6 feet tall with large compound leaves and globe-shaped flower clusters. All parts are edible with a sweet, celery-like flavor.
Knox County, 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 Angelica to ensure they mature before fall.
Knox County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.8
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 Knox County
How your county's soil matches Angelica's growing requirements.
Soil pH
Your soil pH (6.0–6.8) is within Angelica's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Knox County is excellent for Angelica — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.5%) — Angelica will thrive.
How to Plant Angelica
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Angelica
Angelica needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Angelica Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 6.5" | 3.4" | 3.1" | 💧 Light watering |
| May | 6.5" | 3.9" | 2.6" | 💧 Light watering |
| Jun | 6.5" | 3.6" | 2.9" | 💧 Light watering |
| Jul | 6.5" | 4.1" | 2.4" | 💧 Light watering |
| Aug | 6.5" | 3.5" | 3" | 💧 Light watering |
| Sep | 6.5" | 2.6" | 3.9" | 🚿 Regular watering |
| Oct | 6.5" | 2.7" | 3.8" | 🚿 Regular 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.
Angelica 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.
Angelica Planting Timeline — Knox County, IL
Angelica Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | April 3 | Apr 3 – Apr 24 |
| Fall Sowing | August 6 | Aug 6 – Aug 20 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | — |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
365–730 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
181 days in Knox County
Growing Tips for Angelica in Knox County
Direct sow Angelica outdoors after April 17 in Knox County when soil has warmed and frost danger has passed.
Your 181.0-day growing season in Knox County is tight for Angelica (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Angelica in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Sow fresh seeds in fall for spring germination. Provide rich, moist soil and partial shade. Harvest stems in the second year before flowering for candying or flavoring.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Angelica in Other Locations
Frequently Asked Questions
When should I plant Angelica in Knox County, IL?
Knox County is in Zone 5b with an average last frost of April 17. Plan your Angelica planting based on this frost date — see the calendar above for exact timing.
What planting zone is Knox County, IL?
Knox County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 17 and first fall frost is October 15.
Your Knox County Garden Planner — Free
A 24-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.