Getting it to bloom

Why won't my Sweet Black-Eyed Susan bloom? (and how to make it flower)

Also called Sweet Black-Eyed Susan, Sweet Coneflower (Rudbeckia subtomentosa).

More about sweet black-eyed susan

About Sweet Black-Eyed Susan

Rudbeckia subtomentosa · also called Sweet Black-Eyed Susan, Sweet Coneflower · flowering

A long-lived, tall prairie perennial producing masses of golden-yellow daisy flowers with dark brown central cones from late summer into autumn. It has a light, sweet anise-like fragrance and sturdy, multi-branched stems up to 1.5 m tall. Exceptionally tolerant of wet or clay soils, it thrives in rain gardens, moist meadows, and sunny borders with minimal care.

Plant type: flowering

Watch for — Self-seeding and spread: Plants self-seed prolifically if not deadheaded. In borders, remove spent flower heads before seed matures. In naturalistic meadows this spreading habit is an asset.

The reasons sweet black-eyed susan isn't blooming

Almost every non-blooming sweet black-eyed susan traces back to one of these, roughly in order of how common they are:

Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
The plant has not been deadheaded, so it stops flowering once it sets seed.
Irregular watering — drought or waterlogging at the budding stage makes buds abort.
It is still too young or was checked by a transplant and is rebuilding before flowering.

Feeding sweet black-eyed susan a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.

The fix — how to get sweet black-eyed susan to flower

Maximise sun. Give sweet black-eyed susan the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for sweet black-eyed susan and get the feeding right with the sweet black-eyed susan fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Sweet Black-Eyed Susan flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.

Post-bloom care so it flowers again

Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.

For everything else this plant needs day to day, see the full sweet black-eyed susan care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Sweet Black-Eyed Susan blooming — frequently asked questions

Why won't my sweet black-eyed susan flower?

Sweet Black-Eyed Susan blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.

How do I make sweet black-eyed susan bloom?

Give sweet black-eyed susan the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.

When does sweet black-eyed susan normally bloom?