When to Plant Sorrel in Howard County, IA
Your May gardening checklist
A quick May briefing for Howard County, Iowa gardeners — what's urgent, what's next, and what can wait.
June prep starts now
- Starting indoors: sorrel
- First harvests: sorrel
Sorrel is a perennial herb with tangy, lemon-flavored arrow-shaped leaves. It is one of the first greens to emerge in spring and is used in soups and salads.
Howard County, Iowa is in USDA Zone 4b. The average last spring frost is May 4 and the first fall frost is October 5, giving you a growing season of approximately 154 days.
At an elevation of 1,297 feet, Howard County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Sorrel to ensure they mature before fall.
Howard County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-7.3
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 Howard County
How your county's soil matches Sorrel's growing requirements.
Soil pH
Your soil pH (6.1–7.3) overlaps with Sorrel's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Howard County is excellent for Sorrel — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Sorrel will thrive.
How to Plant Sorrel
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Sorrel
Sow every 4.6 weeks. Last sowing by Aug 06 to harvest before frost.
For a dedicated fall crop, sow by Jul 13.
Plant Water Budget
Monthly Watering Guide for Sorrel
Sorrel needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Sorrel Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | — | 3.9" | 0" | ❄️ Dormant |
| May | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4" | 0.3" | 💧 Light watering |
| Sep | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Oct | 4.3" | 3.3" | 1" | 💧 Light watering |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Howard County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sorrel 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.
Sorrel Planting Timeline — Howard County, IA
Sorrel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | April 27 | Apr 27 – May 11 |
| Direct Sow | April 27 | Apr 27 – May 18 |
| Harvest | June 8 | Jun 8 – Aug 10 |
| Fall Sowing | July 13 | Jul 13 – Jul 27 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
154 days in Howard County
Growing Tips for Sorrel in Howard County
Direct sow Sorrel outdoors after May 04 in Howard County when soil has warmed and frost danger has passed.
Your generous 154.0-day season in Howard County allows multiple plantings of Sorrel. Sow every 20.0 days for continuous harvest.
General growing tips
Direct sow in early spring or fall. Remove flower stalks promptly to encourage leaf production. Divide clumps every 3-4 years. Young leaves have the best flavor.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Sorrel in Other Locations
Frequently Asked Questions
When should I plant Sorrel in Howard County, IA?
Howard County is in Zone 4b with an average last frost of May 4. Plan your Sorrel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Howard County, IA?
Howard County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is May 4 and first fall frost is October 5.
Your Howard County Garden Planner — Free
A 24-page printable planner built for Howard County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.