What to plant in March in zone 3b
73 crops to start indoors, direct sow, or transplant in March in USDA hardiness zone 3b. Typical last spring frost around May 17, 2026, first fall frost around Sep 26, 2026 — exact dates vary by location within the zone.
Zone 3b covers a lot of ground. Enter your ZIP for March dates from your nearest weather station and a month-by-month calendar:
Start indoors
Sow these under lights or on a windowsill now for transplants later.
- Achillea
- Agastache
- Aji Pepper
- Alpine Strawberry
- Angelica
- Arugula
- Bee Balm
- Bishop's Flower
- Bok Choy
- Broccoli
- Broccoli Raab
- Brussels Sprouts
- Cabbage
- Cardoon
- Catnip
- Cauliflower
- Celtuce / Stem Lettuce
- Chicory
- Chinese Broccoli
- Chinese Cabbage
- Clasping Coneflower
- Collard
- Creeping Thyme
- Echinacea
- Endive
- Evening Primrose
- Hamburg Parsley
- Horehound
- Hybrid Coneflower
- Hyssop
- Japanese Mugwort
- Kale
- Kohlrabi
- Komatsuna Mustard
- Lavender
- Lemon Balm
- Lemon Mint
- Lettuce
- Lovage
- Marjoram
- Mexican Tarragon
- Mibuna
- Mitsuba
- Mizuna
- Oregano
- Paracress
- Parsley
- Pennyroyal Mint
- Pepper (Habanero)
- Pepper (Sweet & Hot)
- Purple Yu Choy Sum
- Radicchio
- Roman Chamomile
- Romanesco Broccoli
- Rue
- Russian Kale
- Russian Sage
- Sage
- Salad Burnet
- Savory
- Sheep Sorrel
- Siberian Kale
- Soapwort
- Stevia
- Sweet Woodruff
- Tansy
- Tarragon
- Tat Soi
- Thyme
- Veined Catmint
- Vietnamese Culantro
- Wormwood
- Yu Choy Sum
Keep going
Timings use NOAA 1991–2020 climate normals for a representative location (Hannah, ND) in zone 3b, computed with the same engine as GardenDraft’s in-app schedule. Guidance, not guarantees — your exact dates depend on your address.