Black-Eyed Susan

60d to harvest

Velvety petals in warm golden amber flare outward from a nearly inky, button-dark center, creating a sunburst bloom that feels luminous even on the calmest days. Black-Eyed Susan forms sturdy, upright clumps with a graceful, airy presence—its flowers hold their shape and texture beautifully as they sway. Grow it for long-lasting garden color in beds and borders, where its bold, high-contrast blooms make a striking statement from early summer into fall.

Crop Dates

Growing note: In frost-free Zone 11b, grow this cool-season crop during the cooler dry season (October–February).

Milestone	Date
Start Indoors	—
Climate	Frost-Free Climate
Transplant / Sow Outdoors	Oct 1st
Harvest Begins	Nov 30th
Harvest Ends	Feb 28th

Crop Details

Trait	Value
Days to Maturity	60
Sun Requirements	Full Sun
Growth Habit	Upright
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	45
Min Night Temp (°F)	35
Harden Off (days)	7

Frequently Asked Questions

How do I prevent and treat powdery mildew on Black-Eyed Susan (Rudbeckia hirta) in humid weather?

Powdery mildew shows up as a white, dusty coating on leaves, usually after warm, humid spells. Improve airflow by spacing plants 12–18 in. apart and watering at the soil line (not the foliage). If it appears, spray with potassium bicarbonate or a labeled fungicide and remove badly affected leaves to slow spread.

How often should I water Black-Eyed Susan during the main growing phase (after seedlings establish)?

Water deeply about 1 inch per week during active growth, then let the top 1–2 in. of soil dry slightly before watering again. In hot, dry weeks you may need 2–3 waterings per week, but always avoid soggy soil since Rudbeckia quickly suffers from root problems. A simple test: if the soil feels dry and crumbly at 1–2 in. down, it’s time to water.

How can I tell when Black-Eyed Susan is ready to harvest?

Harvest cut flowers when the center disk is mostly open and the petals are fully expanded, typically around 60 days from sowing. For seed, wait until the ray petals wither and fall and the central disk turns dark and dry; shake the head gently and harvest when seeds don’t cling loosely. Dry harvested seed heads in a well-ventilated area for 1–2 weeks before storing.