🥦 When to Plant Cauliflower in Zone 3

Short answer: transplant May 1 – May 15. Here's the full schedule, built from zone 3's typical frost dates.

TaskWindow
Start seeds indoors
7–5 weeks before last frost
Mar 27 – Apr 10
Transplant outdoorsMay 1 – May 15
Fall planting
counted back from first frost
Jun 14 – Jun 28
Zone 3 frost window
May 15 → Sep 20
~128 frost-free days
Spacing
18″ / 30″
plants / rows
Maturity
60–80 days
from transplant

Growing cauliflower in zone 3

Cauliflower wants steady, uninterrupted growth: any stress from heat, cold, or drought shows up in the curd. Fall crops are more forgiving than spring in most regions. Tie leaves over white varieties to blanch.

Zone 3 covers northern Minnesota and North Dakota, northern Maine, high mountain valleys — roughly 120 frost-free days — start warm-season crops indoors, lean on cool-season crops. Zone dates are medians: frost timing varies within a zone with elevation and terrain, so treat these windows as a solid default and refine them with your own city’s dates below.

Make it local

These windows use zone 3's typical frost dates (last frost ~May 15, first frost ~Sep 20). For windows computed from your frost dates, run the ZIP code frost lookup and open the planting calendar — it remembers your city. The seed starting scheduler turns the whole seed rack into one printable, date-sorted list.

Frequently asked questions

When do I plant cauliflower in zone 3?

Transplant May 1 – May 15, counted from zone 3's typical last frost around May 15. It handles a light frost but not a hard freeze, so watch the forecast early in the window.

When should I start seeds indoors for cauliflower in zone 3?

Sow indoors Mar 27 – Apr 10 — that's 7 to 5 weeks before the typical May 15 last frost, giving sturdy transplants exactly when the garden is ready for them.

Can I direct sow cauliflower in zone 3?

Not usefully in zone 3 — cauliflower needs more growing time than direct sowing allows, which is why it's raised from transplants started indoors Mar 27 – Apr 10.

Can I plant cauliflower for a fall harvest in zone 3?

Yes — sow Jun 14 – Jun 28, counted back from the typical Sep 20 first frost so plants mature before serious cold. Time it so harvest wraps up before the first frost.