When to Plant Potatoes in Whiteside County, IL
Your May game plan for Whiteside County, Illinois
We've pulled the most time-sensitive tasks for Whiteside County, Illinois this May and put them front and centre. Tackle them in order.
To set up a strong June, finish these tasks
- Starting indoors: potatoes
Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.
Whiteside County, Illinois is in USDA Zone 5b. The average last spring frost is April 16 and the first fall frost is October 16, giving you a growing season of approximately 183 days.
At an elevation of 682 feet, Whiteside County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Potatoes to ensure they mature before fall.
Whiteside County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
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 Whiteside County
How your county's soil matches Potatoes's growing requirements.
Soil pH
Your soil pH (5.9–6.7) overlaps with Potatoes's range (5.0–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Whiteside County is excellent for Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Potatoes.
How to Plant Potatoes
Succession Planting Potatoes
Sow every 8 weeks. Last sowing by Jun 18 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Potatoes
Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.3" | 1" | 💧 Light watering |
| May | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Jun | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jul | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Aug | 4.3" | 3.3" | 1" | 💧 Light watering |
| Sep | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Oct | 4.3" | 2.3" | 2" | 💧 Light watering |
| Nov | — | 2.1" | 0" | ❄️ Dormant |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Whiteside County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Potatoes 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.
Potatoes Planting Timeline — Whiteside County, IL
Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 19 | Feb 19 – Mar 5 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Harvest | July 9 | Jul 9 – Sep 17 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
70–120 days
🧪 Soil pH
Needs 5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
183 days in Whiteside County
Growing Tips for Potatoes in Whiteside County
Direct sow Potatoes outdoors after April 16 in Whiteside County when soil has warmed and frost danger has passed.
Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Potatoes in Other Locations
Frequently Asked Questions
When should I plant Potatoes in Whiteside County, IL?
Whiteside County is in Zone 5b with an average last frost of April 16. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Whiteside County, IL?
Whiteside County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 16 and first fall frost is October 16.
Your Whiteside County Garden Planner — Free
A 24-page printable planner built for Whiteside 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.