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Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

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Thursday - September 30, 2004

From: Philadelphia, PA
Region: Mid-Atlantic
Topic: Wildflowers
Title: Care of native black-eyed susans after blooming
Answered by: Stephen Brueggerhoff

QUESTION:

What is the best way to take care of black-eyed susans once they have lost their blooms? Am I supposed to cut them down to the base, or just let them die out naturally. Also, they all have a white residue on their leaves, which I understand is a common mildew for them. Will this affect these plants returning next year?

ANSWER:

Black-eyed Susan (Rudbeckia hirta) is a short-lived perennial, sometimes considered and treated as an annual plant. Since the vegetation will die-back, and if the maturing seed is not affected by the mildew, then it will not be a detriment. As with any seed producing plant that you wish to propagate through built-up populations in the garden, allow the seed to mature before cutting back declining plant material. You can then either collect the seed for sowing in the Fall, or leave the spent flower heads in the garden to renew populations in the Spring. Look in the Native Plant Database for more information about Rudbeckia hirta.

 

From the Image Gallery


Black-eyed susan
Rudbeckia hirta

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