When should I plant Sweet Potato in Zone 4b?

Start Sweet Potato seeds indoors around Mar 6. Transplant outdoors after May 22. Expect first harvest around Aug 20.

What is the last frost date for Zone 4b?

The average last spring frost date for Zone 4b is May 1. The first fall frost averages Oct 5, giving a 157-day growing season.

Can I grow Sweet Potato in Zone 4b?

Yes. Sweet Potato needs 100 days to harvest. Zone 4b has a 157-day growing season, which is sufficient.

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🍠 Growing Sweet Potato in Zone 4b

Zone 4b has cold winters and a moderate growing season. Timing is key for Sweet Potato in this zone. Last frost: May 1. First frost: Oct 5.

Planting Calendar

Indoor

Outdoor

Harvest

Mar 6Oct 5

Season: May 1 – Oct 5 (157 days)

Zone4b

Last FrostMay 1

First FrostOct 5

Season Length157 days

Days to Harvest100

SunFull Sun

Frost ToleranceNone

Spacing1/sqft (12" apart)

When to Plant Sweet Potato in Zone 4b

Start Seeds Indoors: Mar 6

Start Sweet Potato seeds indoors around Mar 6 (8 weeks before last frost). Optimal germination temperature: 85°F. Germinates in 14–21 days.

Transplant Outdoors: May 22

Transplant Sweet Potato seedlings outdoors after May 22. Wait until soil temperature reaches 65°F. Space plants at 1/sqft (12" apart). Harden off plants for a week before moving outside.

Harvest: Aug 20

First harvest approximately Aug 20 (~90 days from transplant). Continue harvesting until first frost (Oct 5).

Companion Planting

✅ Dill ✅ Oregano ✅ Thyme

Sweet Potato in Other Zones

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Plan Your Sweet Potato Garden

Track Sweet Potato from seed to harvest with personalized frost dates, watering recommendations, and companion planting visualization.

Start Free Sweet Potato Growing Guide