When to Plant Eggplant in Harrison County, MO
Eggplant is a heat-loving solanaceous crop that produces glossy fruits in purple, white, or striped varieties. It requires long, warm growing seasons for best production.
Harrison County, Missouri is in USDA Zone 5b. The average last spring frost is April 19 and the first fall frost is October 15, giving you a growing season of approximately 179 days.
At an elevation of 1,349 feet, Harrison County receives approximately 37.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Eggplant to ensure they mature before fall.
Harrison County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.9
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 Harrison County
How your county's soil matches Eggplant's growing requirements.
Soil pH
Your soil pH (5.6–6.9) is within Eggplant's preferred range (5.5–7.0).
Soil Texture
The silt loam soil in Harrison County is excellent for Eggplant — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Eggplant.
How to Plant Eggplant
Succession Planting Eggplant
Sow every 7.4 weeks. Last sowing by Jul 22 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Eggplant
Eggplant needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.
| Month | Eggplant Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 4.8" | 3.8" | 1" | 💧 Light watering |
| May | 4.8" | 4.5" | 0.3" | 💧 Light watering |
| Jun | 4.8" | 4.3" | 0.5" | 💧 Light watering |
| Jul | 4.8" | 3.9" | 0.9" | 💧 Light watering |
| Aug | 4.8" | 3.9" | 0.9" | 💧 Light watering |
| Sep | 4.8" | 3.4" | 1.4" | 💧 Light watering |
| Oct | 4.8" | 2.6" | 2.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Harrison County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Eggplant 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.
Eggplant Planting Timeline — Harrison County, MO
Eggplant Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 8 | Feb 8 – Feb 22 |
| Transplant Outdoors | May 3 | May 3 – May 17 |
| Direct Sow | April 26 | Apr 26 – May 17 |
| Harvest | July 12 | Jul 12 – Sep 13 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | 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
1.1"/week · Only during dry spells
📅 Days to Maturity
65–85 days
🧪 Soil pH
Needs 5.5–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
179 days in Harrison County
Growing Tips for Eggplant in Harrison County
Direct sow Eggplant outdoors after April 19 in Harrison County when soil has warmed and frost danger has passed.
Common pests for Eggplant in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 8-10 weeks before last frost. Transplant only after nighttime temperatures stay above 55F. Mulch to retain moisture and warmth around roots.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Eggplant in Other Locations
Frequently Asked Questions
When should I plant Eggplant in Harrison County, MO?
Harrison County is in Zone 5b with an average last frost of April 19. Plan your Eggplant planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harrison County, MO?
Harrison County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 19 and first fall frost is October 15.
Plan Your Garden with Confidence
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