🌶️ When to Plant Radishes in Zone 4

Short answer: sow Mar 31 – Apr 14. Here's the full schedule, built from zone 4's typical frost dates.

TaskWindow
Direct sowMar 31 – Apr 14
Fall planting
counted back from first frost
Aug 20 – Sep 3
Zone 4 frost window
May 5 → Oct 1
~149 frost-free days
Spacing
2″ / 6″
plants / rows
Maturity
22–30 days
from sowing

Growing radishes in zone 4

The fastest vegetable in the garden — and the most often ruined by crowding, so thin early. Sow small amounts weekly; in summer heat they bolt and turn pithy, so pause until fall.

Zone 4 covers northern Plains, northern New England, much of Montana and Wyoming — about 150 frost-free days — most vegetables work, long-season melons are a stretch. 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 4's typical frost dates (last frost ~May 5, first frost ~Oct 1). 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 radishes in zone 4?

Direct sow Mar 31 – Apr 14, counted from zone 4's typical last frost around May 5. As a hardy crop it tolerates the light frosts on either side of that window.

Can I direct sow radishes in zone 4?

Yes — direct sow Mar 31 – Apr 14. This crop prefers direct sowing; its roots dislike transplanting.

Can I plant radishes for a fall harvest in zone 4?

Yes — sow Aug 20 – Sep 3, counted back from the typical Oct 1 first frost so plants mature before serious cold. Light fall frosts improve flavor rather than ending the crop.