When to Plant Endive in Humboldt County, IA
Endive is a leafy green with a slightly bitter flavor, available in curly (frisee) and broad-leaved (escarole) types. It adds texture and complexity to salads.
Humboldt County, Iowa is in USDA Zone 4b. The average last spring frost is April 29 and the first fall frost is October 6, giving you a growing season of approximately 160 days.
At an elevation of 822 feet, Humboldt County receives approximately 31.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Endive to ensure they mature before fall.
Humboldt County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.7
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Endive Planting Timeline — Humboldt County, IA
Endive Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 18 | Mar 18 – Apr 1 |
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Direct Sow | April 22 | Apr 22 – May 13 |
| Fall Sowing | July 14 | Jul 14 – Jul 28 |
| Harvest | June 17 | Jun 17 – Jul 22 |
Plant 0.5" deep · 6" 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 | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
45–65 days
Soil pH
5.5 – 7
USDA Zone
Zone 4b
Growing Season
160 days
Growing Tips for Humboldt County
Sow seeds directly in spring or fall. Blanch heads by tying outer leaves together 2-3 weeks before harvest to reduce bitterness. Keep soil evenly moist.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Endive in Other Locations
Frequently Asked Questions
When should I plant Endive in Humboldt County, IA?
Humboldt County is in Zone 4b with an average last frost of April 29. Plan your Endive planting based on this frost date — see the calendar above for exact timing.
What planting zone is Humboldt County, IA?
Humboldt County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 29 and first fall frost is October 6.
Plan Your Garden with Confidence
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