Rudbeckia Maxima (rud-BEK-ee-a, MAKS-ih-muh) is an upright flowering plant and a member of the Asteraceae family (Aster family).
The genus “rudbeckia” honors a 17th-century Swedish botanist and the founder of the Botanical Garden in Uppsala, Sweden – Olof Rudbeck.
This herbaceous perennial is native to central and southern United States including Oklahoma, Louisiana, Arkansas, and Texas.
Owing to its popularity, Rudbeckia Maxima has garnered a few common names as follows:
- Giant Coneflower
- Great Coneflower
- Giant Brown-Eyed Susan
- Cabbage Leaf Coneflowers
Other Rudbeckia Plants you may like:
Rudbeckia Maxima Care
Growth and Size
Rudbeckia Maxima is a tall, slender flowering plant with a maximum height of 8’ feet tall.
It features large, blade-shaped, powder blue leaves rosette of up to 2’ feet tall and 0.8’ feet wide.
In addition to the basal leaves, the attractive blue foliage is distinguished for its tremendously tall stalks, attractive seed heads, and golden coneflowers.
Flowering and Fragrance
In the summer season, giant flower stalks shoot up in a great length, bearing slightly droopy wildflowers with yellow rays.
Centered with dark brown cones, these bright radial flowers grow up to 2” – 6” inches in size and feature at least 7 – 20 petals.
The bloom time of these native wildflowers is from late spring to early summer and the bloom color is golden yellow.
In fall and winter, the giant coneflower produces tiny, brown, dry fruits.
Light and Temperature
Rudbeckia Maxima prefers full sun or partial shade for optimum growth.
Ideally, the plant thrives best in a sunny location where it receives bright sunlight in its growing season.
However, excessive light and shade hinder the development of the plant and prevent it from flowering.
The USDA hardiness zone of Rudbeckia Maxima is from 5 to 9.
Plant lovers residing in these USDA zones should consider the plantation of these lively native plants of North America.
The average temperature required by the giant brown-eyed Susan is 40° degrees Fahrenheit (4° C).
Watering and Feeding
- The flowering species requires normal watering once it is well-established.
- Provide an inch of water to the plant once a week.
- However, in the first two years of cultivation, the plant needs regular watering, depending on the weather conditions.
- Avoid overwatering to control diseases and pest infestation.
- The evergreen perennial will grow with any of these three types of fertilizers: granular quick-release fertilizers, slow-release fertilizers, and organic fertilizers.
- Follow the directions on the label to fertilize the plant properly in the right season.
Soil and Transplanting
Rudbeckia Maxima grows well in a wide range of soils – sandy, clay, or loamy soil. This tall-growing perennial thrives well even in poor soil.
Whatever soil the plant grows in, make sure it is well-drained.
The soil moisture the plant tolerates is from well-moist to dry.
A notable characteristic of great coneflowers is they produce self-sown seedlings.
These seeds are used for transplanting into a flowerbed.
- First and foremost, prepare the bed with planting holes.
- Space each hole appropriately to ensure proper development of the plant.
- Liftoff the seedling with the soil using a garden trowel and transfer it in the prepared flowerbed.
- Firm the soil with the hands and water thoroughly.
- Provide partial shade until the root system remains unstable.
Grooming and Maintenance
This low-maintenance plant requires light pruning annually.
Ideally, the plant should be trimmed when it reaches up to 2’ feet tall.
Cut back 1” or 2” inches of the inner and outer shoots to prevent the plant from turning floppy.
Make sure to trim any infected or damaged parts using a sanitized tool.
How To Propagate Great Coneflower
These plants are propagated by seeds and the division of rhizomes.
When propagating with seeds, sow seeds either in fall or spring.
Make sure to cover the seeds and plant in well-drained and moist soil.
Germination usually takes place in two weeks.
However, it typically takes the plant approximately 2 years to develop the desired size and shape.
If propagating by divisions, divide the perennial in summer or spring and every 3 or 4 years to prevent overcrowding.
Great Coneflower Pests and Diseases
The mature, well-developed plant is deer resistant, but the young ones may get nibbled by animals.
The Black-eyed Susan plant is also susceptible to insects such as slugs and snails.
They attack the basal foliage by causing holes in them and feed on the seedlings.
The plant is subject to a wide variety of diseases such as:
To prevent the plant from these pests and diseases, keep the perennial and it’s surrounding neat and tidy with good air circulation.
Eliminate discolored or diseased leaves and flowers upon the first sight.
Rudbeckia Maxima Uses
The lovely great coneflower is a wildlife attractant, alluring pollinators such as butterflies, hummingbirds, goldfinches and other songbirds toward its nectar.
The tall perennial is also popularly used as cut flowers and in cottage gardens as a groundcover.