my LocalPlanting

When to Plant Black-eyed Susan in Simms, Montana (59477)

Location

Simms, Montana

ZIP Code

59477

USDA Zone

4b

Last Frost

Tuesday, May 5, 2026

๐Ÿ“… Planting Calendar

Direct Sow Outdoors Tuesday, April 7, 2026

Pro Tip: Sow Black-eyed Susan directly outdoors 4 weeks before your last frost date.

๐ŸŒฟ Plant Details

Scientific Name Rudbeckia hirta
Days to Maturity 85 days
Mature Height 18-36"
Spread 18"
Type Annual/Perennial

โ˜€๏ธ Growing Requirements

โ˜€๏ธ

Sun

Full Sun (6-8 hours)

๐Ÿ’ง

Water

Low (drought tolerant)

โ†”๏ธ

Spacing

18" apart

๐ŸŒฑ

Planting Depth

0.13" deep

Seeds typically germinate in 7-14 days

Ready to Plant Black-eyed Susan in Simms?

Get your seeds now so they're ready by Tuesday, April 7, 2026.

* Affiliate links โ€” we may earn a small commission at no extra cost to you.

๐Ÿค Good Companions

EchinaceaLavenderSageSwitchgrass

Other Plants for Simms

Growing Black-eyed Susan in Zone 4b

Black-eyed Susan (Rudbeckia hirta) is a popular garden vegetable. In Simms, Montana, which is in USDA Hardiness Zone 4b, you should direct sow seeds around Tuesday, April 7, 2026.

Your average last frost date is Tuesday, May 5, 2026. Black-eyed Susan grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.