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Black-Eyed Susan Brings Cheerful Colour

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A clump of Rudbeckia Hirta Black Eyed Susans along a walkway

Many people consider the ‘Gloriosa Daisy’ to be one of the most beautiful things to come from a seed packet. It is an “average gardener’s” flower that will satisfy even the most discerning connoisseurs. Black-eyed Susan is a cheerful, widespread plant with daisy-like flowers, vibrant yellow rays, and domed, dark brown center disks. The stems and oval leaves are covered with bristly hairs. Rudbeckia is a biennial plant. The first year, it creates a rosette of leaves at ground level, followed by blooms the second year. It reseeds fast, so blossoms can be seen year after year. It grows well in clusters.

Black-eyed Susan’s bright yellow flowers attract many different pollinators. It is one of the larval host plants of the Silvery Checkerspot butterfly. The flowers also appeal to other butterflies, moths, bees, wasps, flies, and beetles. The seed heads provide good winter interest as well as food for birds.

Quick Growing Guide

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Botanical Name: Rudbeckia hirta

En français: Rudbeckie hérissée

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Colour:

Blooms:

Water: One inch a week in the first year, drought resistant when established

Pollinators:

Hardiness Zones:

Consider planting rudbeckias in bunches in a layered garden with other colourful summer and fall bloomers. Use our plant selection tool to serch for alternatives.

Gloriosa Daisies Grow In Plain Old Dirt

The soil does not need to be moist, mellow, or rich for these daisies to grow. They can withstand – and even enjoy – hot sun and produce an abundance of amazingly long-lasting, diverse, and beautiful flowers all summer long. Gloriosa Daisies are almost literally everyday small country flowers.

Varied Forms and Colors

There is never an unattractive one among them, and many are outstanding. In the centre of each is a large, dark-colored cone of disc flowers. Petal shapes can be nearly flat, arch out and down, or quill and twist gracefully. Colors range from a brilliant clear yellow to gold and orange, and then to rich bronzy reds, maroons, and mahoganies. Some flowers are selfs, but the majority are eyed and zoned patterns with sharply contrasting areas or subtle blendings of one shade into another. Because they are big daisies, often five to six inches across, abundantly produced and displayed well above the foliage on tall stems, they all blend beautifully in mass plantings and provide an eye-full of colour.

The stems are strong with a lasting quality make them a good choice for cutting.

A Rating Well Deserved

Gardeners who grew Gloriosa Daisies in moderate quantities from the start were occasionally intrigued by plants with semi-double and even double flowers. So it was not surprising but welcome news in 1961 to learn that Gloriosa Double Daisies, another Burpee introduction, was one of the All-America flower selections—a Silver Medal winner. Unlike the others, these did not have a typical “daisy” form, but rather resembled golden yellow chrysanthemums with their many petals. Some of the blooms are semi-double, with partially open centres revealing the single type’s dark eye.

Pinwheel, a popular bicolor pattern of mahogany and gold single-flowered Gloriosa Daisy, will be available to the general public in 1963. We’re still learning about the culture of these daisies because they’re so new. Each grower who tries them can add to the general pool of gardening knowledge in their area. Growing them is not difficult; in fact, it is quite simple. They can, however, be handled in a variety of ways, and a little experience will teach you the best method. There’s even some debate about how to categorise them. They’ve been listed as both hardy annuals and perennials, and in some gardens, they’ve turned out to be biennials!

Seeds

Similar to its sister plant, the Sunflower, the eyes of the Black-Eyed Susan are the source of its seeds. You can allow the seeds to dry on the stem for reseeding or collect and dry them in other ways for replanting elsewhere. They can be harvested by drying up the seed head when the blooms turn brown or faded/Black-eyed Susan has seeds that look like smaller rice grains with black coloring. 

Close up of Black-eyed Susan Flower with a a pollinator
Credit: Plismo, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons

Black-eyed Susan can grow up to six to seven feet tall, but their size can change dramatically depending on the variety you grow. They can appear to be a few inches to a few feet tall. The plant grown from its seed tends to be a bit smaller in size than its parent plant. 

Will Bloom In One Season

They can grow as annuals. With seeds started in a flat at a sunny window in February or March, many have no trouble getting flowering plants by late summer. For large, many-branched plants, however, and maximum, long-season flower production, work them on a two-year cycle. Start seeds in midsummer in a flat. While any humusy, pulverized soil would probably do, use the following:

  • Two parts by bulk measure of vermiculite
  • Two parts perlite
  • One part shredded peat moss
  • Mix together and moistened.

Practically every sown seed sowed in this mix will germinate and grow well if watered occasionally with liquid plant food. When seedlings are large enough to transplant, shift them to the ground, about six inches apart in a row alongside the vegetable garden where space is reserved for flowers. This operation may involve a little shading and watering for a few days, as it comes during a usually hot and dry season.

Drought Tolerant Once Established

Once established, Black-eyed Susans are fairly drought tolerant, low-maintenance, self-seeding, and disease resistant with few necessary care requirements. However, in the first year, water about an inch a week until the plant is established. Powdery mildew can form on their foliage when there is lingering water on the foliage. Thus, they should be spaced appropriately and watered at the soil level rather than from above. Regarding their growth, they thrive under partial to full sunlight with a neutral pH level in the soil.

Deadheading Rudbeckia

Deadheading is a major part of Black-eyed Susan’s care as they can reseed faster when kept intact. Since seeds are contained in the blooms of the black-eyed Susan, it can slow or stop their spread. Otherwise, the seeds of these plants spread throughout the garden as the flowers fade and dry up. Deadheading also allows the plant to grow a sturdier body and spurs more blooms.

Perhaps Will Need Stakes

Gloriosa Daisies, which are a year old, help brace themselves by branching out and merging together. Because they grow to be two to three feet tall and half as wide, a little extra support is recommended. Drive inconspicuous stakes behind the plants and wrap soft tomato twine around them to keep the rain from tearing off branches or knocking over entire plants. The flowers themselves are remarkably long-lasting, lasting for weeks and weeks in our hottest summer weather.

Companion Plants to Repel Fauna

Planting these plants alongside strong-scented companion plants such as rosemary or lavender can be the best possible repellent against rabbits, varmints, or deer. Rabbits do not specifically target Black-eyed Susan to feed on, but when they come across these biennial flowering plants, they do not hesitate to munch on them.

They are relatively pest free, too.

Surviving Winters

Many of the little plants will branch out into multiple crowns by fall, and there will usually be a bloom or two before frost. However, the foliage mostly develops as a large-leaved rosette that lies close to the ground. These survive Tennessee winters without shelter, despite temperatures reaching zero or a few degrees below zero for brief periods.

A light mulch of straw or similar loose material may be desirable further north, primarily to protect the leaves from cold, drying winds. Because the plants require both light and air, no solid covering should be used. With warmer days the following spring, gloriorsas quickly grow into large, well-branched plants with ample well-matted root systems. Plants can often be lifted and replanted easily with balls of dirt on the roots, even when flower buds are visible. Six-inch spacing is too close for the best bloom development for cutting.

In April, go through with a trowel, lift out each other plant, and transfer to display beds or borders 12′′ to 14′′ apart.

Perennials

Gloriosa Daisies are true perennials and can live for several years in northern areas where summers are cooler. To tell the whole story, my big plants put on a great show as two-year-olds, then died. Nobody has ever survived the following winter. The death of the older plants does not mean I am without daisies. Volunteer seedlings will grow anywhere flowering plants have previously grown.

History Of The Gloriosa

The story started more than 100 years ago with Black-eyed Susan, more formally known as Rudbeckia hirta. The Black-eyed Susan is a common wilding of western prairies which spread to become a roadside weed in eastern and southern states.

The late Dr. Albert F. Blakeslee, a plant scientist then at the University of Connecticut, began collecting different “Susans.” He was interested in the varying flower forms he found in the wild plants. Cross-breeding them, he increased the size as well as number of “ray flowers” or petals until he had fully double blossoms. He worked with the better ones over the years. Part of the time in his garden, and continued with them when he became Director of the Smith College Genetics Experiment Station.

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