Black-eyed susans (rudbeckia) bring a blaze of burnished glory to the garden in the late summer months with their daisy-style flowers.
Also known as coneflowers, rudbeckias come in a range of colours, from yellow to orange, and sizes. There are also annual, biennial and perennial varieties, so there’s plenty of choice, as long as you have a sunny garden or patio. They can be grown in pots, but probably look best when combined with other ‘prairie style’ perennials and grasses.
Rudbeckia, also known as Black-Eyed Susan, Gloriosa Daisy, and Coneflower, is a gorgeous flower that adds a pop of color to any garden. Growing Rudbeckia from seed is easy and rewarding. With just a little care, you can have stunning blooms all season long.
Why Grow Rudbeckia?
There are many reasons to add Rudbeckia to your garden or flower cutting patch:
- Beautiful flowers with golden yellow petals and dark brown/black centers
- Blooms throughout the summer and into fall
- Attracts butterflies, bees, and other beneficial pollinators
- Does well in poor soil and is drought tolerant
- Flowers make excellent cut flowers with long vase life
- Reseeds readily for flowers year after year
Getting Started with Rudbeckia Seeds
Rudbeckia can be started indoors or direct sown outside after the last frost. For best germination, the seeds need light and cool conditions. Here are some tips:
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Start seeds indoors 5-7 weeks before transplanting outside Use a seed starting mix and sow 2-3 seeds per cell Cover very lightly with soil or vermiculite,
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For direct sowing, wait until after the last frost date Scatter seeds on prepared soil and cover very lightly by raking.
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Optimal soil temperature for germination is 68-72°F. Seeds will sprout in 8-14 days.
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Rudbeckia seedlings need 14-16 hours of light per day. Use grow lights if starting indoors.
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Thin seedlings to one strong plant per cell or planting hole. Transplant outside when 4-6 inches tall.
Growing Conditions
Once seedlings are established, Rudbeckia thrives with minimal care. Here are the optimal growing conditions:
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Sun: At least 6 hours of direct sun per day, the more the better.
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Soil: Average, well-drained soil. Does well even in poor, sandy soil.
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Water: Drought tolerant once established, but occasional watering encourages more blooms.
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Spacing: Space plants 12-18 inches apart.
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Fertilizer: Apply a balanced fertilizer or compost in spring.
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Pruning: Deadhead spent blooms to encourage continuous flowering.
When to Harvest Rudbeckia
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For fresh cut flowers, harvest buds that have started to open but before fully open.
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For dried flowers, wait until blooms are completely open.
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Harvest in the morning after the dew has evaporated for best vase life.
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Cut stems 8-12 inches long and place immediately in warm water. Re-cut under water.
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Change water daily and remove any leaves below the water line.
Saving Rudbeckia Seeds
Rudbeckia readily reseeds itself, but you can also easily save seeds for future planting:
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Allow desired flowers to fade completely on the plant.
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Collect dried seed heads and rub to separate seeds. Discard chaff.
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Store seeds in a paper envelope or glass jar in a cool, dry place.
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For best germination, cold stratify seeds for 30 days before planting.
Troubleshooting Common Problems
Rudbeckia is relatively pest and disease free, but may experience:
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Poor germination: Ensure seeds are not planted too deep. Maintain optimal soil temperature and moisture.
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Leggy seedlings: Give more light and use a fan to strengthen stems.
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Few blooms: Needs more sun. Deadhead spent flowers.
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Wilting: Water more frequently, especially in extreme heat.
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Leaf spots: Improve air circulation. Avoid overhead watering.
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Aphids: Use insecticidal soap or neem oil. Attract ladybugs.
With proper care, Rudbeckia is sure to give you months of vivid color and bountiful blooms. This cheerful flower is easy to grow, great for beginners and pros alike. Get your seeds started today!
How to plant rudbeckia
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. Add a general fertiliser as a top dressing, and water in and mulch well.
Watch Monty Don plant rudbeckias in the Jewel Garden.[ id=”29210″ size=”landscape_thumbnail” align=”none” title=”Potting on rudbeckia seedlings” alt=”Potting on rudbeckia seedlings” classes=””] Potting on rudbeckia seedlings
Where to plant rudbeckia
For best results grow rudbeckias in moist but well-drained soil, in full sun. Taller varieties are best at the back of a border, while shorter varieties can be grown in containers or at the front of a mixed border. Some rudbeckias will also tolerate light shade.[ id=”29209″ size=”landscape_thumbnail” align=”none” title=”Sowing rudbeckia seeds in a tray” alt=”Sowing rudbeckia seeds in a tray” classes=””] Sowing rudbeckia seeds in a tray
How to Grow Rudbeckia from Seed
FAQ
Is Rudbeckia hard to grow from seed?
They’re one of the hardiest plants we grow from seed, and so long as you harden off seedlings well they can be planted almost year round (so long as the soil is workable). It’s also good to note that rudbeckia flower best when they have a period of exposure to cold temperatures.
How long does it take for Rudbeckia seeds to germinate?
Rudbeckia Seeds Germination
Rudbeckia seeds should germinate within 14 to 21 days. As the seedlings begin to grow, thin them to around 30cm apart to allow for development. Finally in the autumn transplant the plants to their flowering position allowing 30 to 40cm between each one.
Do Rudbeckia seeds need cold stratification?
Sow and Plant
Perennial rudbeckias can be grown from seed, but the seeds require cold stratification, making them a good subject for winter sowing. Alternatively, start with a purchased plant in spring, or plant divisions taken from the outside of a friend’s clump.
Will Rudbeckia bloom the first year?
It grows quickly from seed and will bloom heavily in its first year, therefore it is best grown as an annual.
Can rudbeckias be grown from seed?
Rudbeckias are easy to raise from seed, which can be sown from spring until midsummer. Sow the seeds directly in a shallow trench or trays, barely covered with seed-raising mix, and transplant them into free-draining soil in full sun once the risk of frosts has passed. Rudbeckias flower in their first year from seed.
How do you grow Rudbeckia laciniata?
The flowers with green centers are surrounded by bright yellow petals on tall stems. 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?
Late Winter is the perfect time to sow Rudbeckia hirta for blooms from later in Summer until the frosts. Pinching Snapdragons Late Winter is the perfect time to sow a 2nd round of Snapdragons, they will bloom slightly later than the Autumn Jump Starter Snapdragons which should now be ready for pinching to create more bouquet sized stems.