Learn how to grow rudbeckia, a flower that doesn’t need much care and is known for its bright yellow and orange petals with a striking black center. Because they are so easy to grow and take care of, rudbeckias are great for people who are new to gardening or just want an easy addition to their garden. I love putting rudbeckia at the end of my raised beds to get butterflies, bees, and other good bugs.
Rudbeckia, commonly known as black-eyed Susan gloriosa daisy or coneflower, is a popular flowering plant native to North America. With its bright golden yellow or orange flowers and dark brown centers it adds cheer and vibrancy to any garden. Though often grown as an annual, Rudbeckia is technically a short-lived perennial hardy in zones 3-9.
If you want to add this rugged beauty to your landscape, growing Rudbeckia from seed is easy and rewarding. Here’s a step-by-step guide to raising a thriving crop of Rudbeckias in your garden.
An Overview of Rudbeckia
Before diving into the growing process let’s go over some key facts about Rudbeckia
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There are over 20 species of Rudbeckia, with the most popular being R. hirta (black-eyed Susan) and R. fulgida (orange coneflower).
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Rudbeckia thrives in full sun and well-drained soil. It is drought-tolerant once established.
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Flowers bloom from June to September in hues of yellow, gold, orange and red.
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The flowers have a distinct cone-shaped center disk surrounded by drooping, daisy-like petals.
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Plants grow 1-3 feet tall depending on variety, with a spread of 1-2 feet. Give them 12-24 inches of space in the garden.
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Though short-lived, Rudbeckia will often reseed itself if some spent flowers are left on the plant.
When to Start Rudbeckia Seeds
Rudbeckia can be started indoors 6-8 weeks before your last expected frost date. It can also be direct sown anytime after danger of frost has passed.
If sowing indoors, be sure to use a seed starting mix and provide plenty of light. Thin sprouted seedlings to avoid overcrowding. Harden off plants for 7-10 days before transplanting outdoors.
Rudbeckia seed will germinate in 7-14 days at soil temperatures of 70°F and above. Some varieties may take up to 30 days, so be patient!
How to Direct Sow Rudbeckia
If sowing Rudbeckia seed directly in the garden, follow these tips:
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Prepare the seedbed by loosening soil and removing weeds/debris. Rudbeckia likes well-drained, average soil.
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Sow seeds 1/4 inch deep, spacing them 12-24 inches apart depending on mature plant size.
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Cover seeds lightly with fine soil or seed starting mix and water gently to avoid washing away seeds.
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Keep soil moist until seeds germinate. Provide partial shade if sowing during hot, dry weather.
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Thin seedlings to final spacing once they produce 2-3 true leaves.
Caring for Rudbeckia Plants
Rudbeckia is easy to grow and quite unfussy once established. Here are some tips for healthy, vigorous plants:
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Water 1 inch per week, allowing soil to dry somewhat between waterings. Established plants are drought tolerant.
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Apply general purpose fertilizer or compost in spring to fuel growth.
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Remove spent flowers to encourage more blooms. Deadhead into fall for best display.
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Cut plants back to 4 inches after hard frost for winter interest and seed production.
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Divide crowded clumps in spring every 2-3 years to rejuvenate.
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Enjoy self-sown seedlings or thin as desired. They transplant easily when young.
Harvesting Rudbeckia for Cut Flowers
With their long vase life, Rudbeckias make fantastic cut flowers. Follow these guidelines:
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Cut stems when flowers start to open, leaving some foliage on the plant.
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Make cuts with sharp, clean pruners in the morning before heat builds.
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Strip lower leaves and recut stems under water to prevent air embolisms.
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Use floral preservative and change water every 2-3 days for best longevity.
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Display out of direct sun for 6-8 days of enjoyment.
Saving Rudbeckia Seeds
Let some flowers go to seed in fall to collect your own Rudbeckia seeds:
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Leave faded blooms on plants until the cone-shaped centers are completely dry.
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Cut these dry seed heads off the plants
How to Grow Rudbeckia: Black-eyed Susan Growing Tips
Rudbeckia is a plant in the Asteraceae family that is native to North America but can now be found growing all over the world.
Rudbeckia blooms from mid to late summer into fall and grows best in temperatures between 70-85°F (21-29. 4°C) during the day and above 55°F (12. 7°C) at night. Once established, Rudbeckia plants can tolerate drought conditions and higher temperatures. Because of this, rudbeckia often lives and grows well in my low desert Arizona garden during the very hot summers.
Rudbeckia is a hardy plant that can also thrive in cooler temperatures. In addition, it can withstand light frost, making rudbeckia a good choice for gardens in cooler climates.
(Frost on rudbeckia in my Mesa, Arizona garden)
How to plant rudbeckia:
Start annual or biennial types from seed. Divide perennial cultivars in the spring or fall.
If you want to get a head start on growing rudbeckia:
- Cold-moist stratify seeds for three to four weeks before planting them indoors or outdoors in warm places. (not always necessary, but can aid in germination/flowering).
- Start indoors 6-8 weeks before planting outside.
- Put the seeds in seed starting mix and water them often until they sprout.
- Harden off seedlings before planting them outside.
- Plant seedlings once they are 3-5” tall.
To plant rudbeckia seeds in the garden, wait until the soil warms to 70°F (21°C). Then, lightly cover the seeds with soil and keep them moist until they germinate.
Plant rudbeckia transplants at the same level as in the nursery pot. Ensure good seed to soil contact and water well.
Growing Rudbeckia from seeds to flowers with step by step update on the growth of Rudbeckia
Can rudbeckias be grown from seed?
Annual and biennial rudbeckias can be grown from seed. Sow seed in early spring and keep seedlings under cover until large enough to handle and pot on, then harden off after danger of frost has passed. Plant out in May. Perennial rudbeckias can be planted at any time of year. Dig a generous planting hole and add plenty of compost or leaf mould.
How do you grow Rudbeckia laciniata?
Perfect for planting along streambanks and pond edges, the 5 – 8 foot plants are best planted in full sun, but also tolerate light shade. Easy to grow from seed, Rudbeckia laciniata often blooms in the first year when grown in cultivation.
When should I plant Rudbeckia hirta?
Fall is an excellent time to plant your Rudbeckia plants, but just make sure they have enough time before frosts become prevalent in order to establish themselves before winter. Potted annual Rudbeckia hirta varieties are best planted after your last estimated frost in the spring. Sow seed in fall or stratified seed in early to mid-spring.