📍 Agate, ND · Zone 3b · Last frost Wednesday, May 20, 2026
✏️ ChangeWhen to Plant Eggplant in Agate, North Dakota (58310)
Location
Agate, North Dakota
ZIP Code
58310
USDA Zone
3b
Last Frost
Wednesday, May 20, 2026
📅 Your 2026 Planting Dates
Start Seeds Indoors
Wednesday, March 25, 2026
Transplant Outdoors
Wednesday, June 3, 2026
Based on last frost Wednesday, May 20, 2026 · Zone 3b
Pro tip: Start Eggplant seeds indoors 8 weeks before your last frost date, then transplant outdoors around Wednesday, June 3, 2026.
🌿 Plant Details
☀️ Growing Requirements
☀️
Sun
Full Sun (6-8 hours)
💧
Water
Regular (1 inch/week)
↔️
Spacing
24" apart
🌱
Planting Depth
0.25" deep
Seeds typically germinate in 7-14 days
Ready to Plant Eggplant in Agate?
Get your seeds now so they're ready by Wednesday, March 25, 2026.
* Affiliate links — we may earn a small commission at no extra cost to you.
🤝 Good Companions
⚠️ Avoid Planting Near
Full Companion Planting Guide for Eggplant
See which plants help Eggplant thrive, which to keep away, and raised bed layout tips →
🛠️ Supplies You'll Need
* Affiliate links — we may earn a small commission at no extra cost to you.
Common Eggplant Varieties
Popular cultivars to look for at your local nursery or seed supplier.
Black Beauty
The classic large-fruited purple-black eggplant; standard variety since 1902.
Fairy Tale
Small, lavender-striped mini eggplants with very tender, sweet flesh; no bitterness.
Ichiban
Long, slender Japanese eggplant with mild, delicate flavor and thin skin.
Listada de Gandia
Striking Italian heirloom with white-and-purple striped skin; mild, creamy flavor.
Common Eggplant Problems
What to watch for — and how to fix it before it spreads.
Pests
Tiny beetles create dozens of small holes in leaves; seedlings can be badly set back.
Use row covers; apply kaolin clay; strong healthy transplants recover better — don't rush transplanting.
Adults and orange larvae defoliate eggplant rapidly; they prefer eggplant even over potatoes.
Handpick adults and egg masses daily; apply spinosad; rotate crops and till after harvest.
Thrive in hot, dry conditions; cause stippled, yellowing leaves and fine webbing.
Keep plants well-watered; spray neem oil or insecticidal soap on leaf undersides.
Diseases
Soil-borne fungus causing yellowing, wilting, and gradual plant death in mid-season.
Plant resistant varieties; rotate crops; solarize soil before planting in problem beds.
Fruit rot and stem lesions; fruit develops brown, sunken areas that spread rapidly.
Apply copper fungicide; harvest promptly; avoid overhead irrigation.
Common Mistakes
Eggplant is extremely cold-sensitive; chilling injury causes long-term stunting even without frost.
Wait until nighttime temps are reliably above 60°F and soil is at least 65°F before transplanting.
Overripe eggplant becomes seedy, bitter, and spongy; the skin loses its sheen when past peak.
Harvest when skin is glossy and fruit gives slightly to pressure; cut with pruning shears, never twist.
🌾 Seed Saving Guide
🟢 EasyWhen to Harvest Seed
Leave fruit on the plant well past edible stage — it will turn yellow-brown and overripen.
Processing
Cut overripe fruit, scoop seeds into water, let viable seeds sink, rinse and dry flat.
Seed Viability
Up to 4 years when stored cool, dark, and dry.
Pro Tip
Eggplant can cross-pollinate between varieties. Isolate by 300 feet for pure seed saving.
Raised Bed Planting Guides
A 4×8 bed fits 8 plants of Eggplant. See plant counts, spacing grids, and companion pairings for every bed size →
Frequently Asked Questions
When should I plant Eggplant in Agate, North Dakota? +
In Agate (Zone 3b), start Eggplant seeds indoors around Wednesday, March 25, 2026 and transplant outdoors around Wednesday, June 3, 2026.
What is the last frost date for Agate, North Dakota? +
The average last spring frost date for Agate, North Dakota (ZIP 58310) is around Wednesday, May 20, 2026. This is based on NOAA climate normals for USDA Zone 3b.
How long does Eggplant take to grow? +
Eggplant typically matures in about 70 days from transplanting. In Agate, that means you can expect harvest around Wednesday, June 3, 2026 plus 70 days.
Should I start Eggplant indoors or direct sow in North Dakota? +
Eggplant should be started indoors 8 weeks before your last frost date. In Agate, that means starting around Wednesday, March 25, 2026.
Other Plants for Agate
Growing Eggplant in Zone 3b
Eggplant (Solanum melongena) is a popular garden vegetable. In Agate, North Dakota, which is in USDA Hardiness Zone 3b, you should start seeds indoors around Wednesday, March 25, 2026.
Your average last frost date is Wednesday, May 20, 2026. Plan to transplant your Eggplant seedlings outdoors around Wednesday, June 3, 2026, about 2 weeks after your last frost date.