SproutSmart
SproutSmart Intelligent Garden Sowing

Zone 3b Planting Schedule

Last spring frost: May 19th
First fall frost: Sep 21st
Growing season: 125 days

Action Plan: August in Zone 3b

Expert Note

In August, keep soil evenly moist and mulch to reduce heat stress; water early to limit foliar disease. Watch for late-season pests like aphids and squash bugs, and remove any yellowing leaves. Feed heavy fruiters lightly every 2–3 weeks if growth slows.

Seed & Soil

Use the warm soil to direct sow quick, cool-season holdovers like New Zealand Spinach and Greek Basil, and tuck in Carrot for a fall harvest. If you have space, transplant Lettuce-type greens equivalents from your list as starts when available, and keep rows evenly watered until established.

The Harvest

Harvest regularly from Amarillo Carrot, Albion, and All American to keep plants producing and prevent quality drop. If you’re growing melons, pick Banana Melon when fragrant and fully colored. For best texture, harvest Broccoli heads promptly at peak size.

Planting Schedule

Add crops from the list below to build your planting schedule.
Crop Indoor Start Transplant / Sow Harvest Window
Artichoke Feb 24th May 5th Oct 2nd – Sep 21st
Giant Red Celery Feb 24th Jun 30th Sep 28th – Sep 21st
Green Sleeves Feb 24th Jun 30th Sep 28th – Sep 21st
Gros Vert de Laon Feb 24th May 12th Aug 10th – Sep 21st
Kojak Feb 24th May 5th Sep 2nd – Sep 21st
Verina Feb 24th Apr 7th Jul 16th – Sep 21st
African Sunset Mar 10th May 19th Aug 17th – Sep 21st
Alabaster Mar 10th May 12th Sep 9th – Sep 21st
Albin Mar 10th May 12th Sep 9th – Sep 21st
Amsterdam Mar 10th May 12th Aug 5th – Sep 21st
Amsterdam Cutting Mar 10th May 19th Jul 28th – Sep 21st
Amsterdam Seasoning Mar 10th May 12th Jul 21st – Sep 21st
Apollo Mar 10th May 12th Sep 9th – Sep 21st
Artichaut de Nice Mar 10th May 12th Sep 9th – Sep 21st
Artichoke de Marseille Mar 10th Jun 30th Sep 28th – Sep 21st
Atlas Angel Mar 10th May 12th Jul 21st – Sep 21st
Baby Artichoke Mar 10th May 12th Aug 5th – Sep 21st
Balder Mar 10th May 19th Sep 1st – Sep 21st
Bandit Mar 10th May 12th Sep 9th – Sep 21st
Beijing White Mar 10th May 12th Jul 31st – Sep 21st
Bing Select Mar 10th May 5th Jul 14th – Sep 21st
Blue Solaise Mar 10th May 12th Aug 30th – Sep 21st
Bordeaux Mar 10th May 19th Aug 2nd – Sep 21st
Bullseye Salmon Mar 10th May 12th Jul 21st – Sep 21st
Cabernet Mar 10th May 12th Aug 30th – Sep 21st
Carmen F1 Mar 10th May 12th Aug 25th – Sep 21st
Cascade Blue Mar 10th May 19th Jul 28th – Sep 21st
Catanese Mar 10th Jul 14th Nov 11th – Sep 21st
Celebration Mar 10th May 5th Jul 24th – Sep 21st
Cherokee Sunset Mar 10th May 19th Jul 28th – Sep 21st

Frequently Asked Questions


What are the frost dates for Zone Zone 3b?
In Zone Zone 3b, the average last spring frost is May 19th and the average first fall frost is Sep 21st.
When is the best time to start seeds indoors in Zone Zone 3b?
The best time to start most seeds indoors is 6 to 8 weeks before your last spring frost date of May 19th.
How long is the growing season in Zone Zone 3b?
Zone Zone 3b has a growing season of approximately 125 days.