How to Plant, Grow, and Care for Brown-Eyed Susans

Brown-eyed Susan grows as a multi-branched, tall wildflower perfect for a cut flower garden. Regular deadheading will encourage even more blooms. These flowers will also attract beneficial insects to your garden. Rudbeckia triloba is the host plant to the silvery checkerspot butterfly and the wavy-lined emerald moth. 

These yellow daisy-like flowers are about one half inch to one inch in diameter and sit atop stems that can reach a height of five feet. The flowers will begin to bloom in late summer and bloom all through the fall. This makes them a great late-bloomer to add to your garden to ensure that something is blooming at all points throughout the growing season. 

Overview

Plant Type Perennial (short-lived) Family Asteraceae Genus Rudbeckia Species Rudbeckia triloba	Native Area Central and Eastern United States Exposure Full sun to partial shade Height 2-5 feet Watering Requirements Drought-tolerant	Pests & Diseases Slugs, powdery mildew Maintenance Low Soil Type Sandy to loamy Soil pH Acidic, neutral

What Are Brown-Eyed Susans?

Brown-eyed Susan, botanically Rudbeckia triloba, are closely related to black-eyed Susan or Rudbeckia hirta. Brown-eyed Susan is taller, with more flowers, and a wildflower appearance.

They have the same daisy-like yellow flowers as black-eyed Susan, but the flowers are smaller, and the centers are lighter in color. Since each plant produces many branches, sturdy stems, and abundant flowers, this makes it a great addition to a cut flower garden. 

History

Rudbeckia triloba has a history of medicinal and culinary uses, including dried flower petals used for tea or ground to flavor soups. The pharmacological properties of Rudbeckia triloba are still being studied today. Nowadays, this native flower is most commonly prized for its ornamental qualities and low-maintenance status in the cut flower garden. 

Native Area

This flower is native to the central and eastern United States from New York to Minnesota and south to Utah and Texas. They can be found in disturbed areas like woodland borders, rocky slopes, and along roadsides. In their native area, they can be found growing in a variety of soil types and are very adaptable as long as they receive enough sunlight. 

Characteristics

Due to its appearance, it is also known as branched coneflower, thin-leaved coneflower, and three-lobed coneflower. It grows in an upright habit and produces many branches from a single main stem.

These branches, in turn, produce many flower heads on long, sturdy stems that sway in the wind. The brown-eyed Susan flowers themselves are smaller in size than their counterparts, the black-eyed Susan, but just as stunning and sunny yellow. 

Uses

These beautiful flowers are used as an ornamental in wildflower gardens and the cut flower garden. They act as a pollinator attractant and will bring many beneficial bugs and bees into your garden.

Brown-eyed Susan is also the host plant to the silvery checkerspot butterfly and the wavy-lined emerald moth. Both of these insects are found in the same native range as this plant. Brown-eyed Susan can also commonly be found in prairie and wildflower seed mixes. 

Where To Buy Brown-Eyed Susan

Brown-eyed Susan seeds are readily available at many online retailers. They can also be found in wildflower mixes like this prairie splendor seed mix and this grandmother’s cut flower garden seed mix. When starting from seed, it’s good to remember that this plant does not produce flowers until its second year. So, you will need to wait a full growing season to enjoy its blooms. 

For this reason, you may opt to purchase a starter plant. Though they are less widely available than black-eyed Susan, they can still be found at some online retailers. If you have a friend with established plants or have them growing in the wild locally, then you may opt to save seeds from these plants. One thing is for sure: once you plant one brown-eyed Susan, you will have plenty of seeds to supply the neighborhood! 

Planting

Rudbeckia seeds do best when exposed to a period of cold stratification, although this isn’t completely necessary. If you want to take the route that mimics nature, then you can crush the dried seed heads at the end of the growing season, sprinkle the seeds around the surface of the soil, and let the snow and spring rains take care of the rest. Or, direct sow seeds three to four weeks before your average last frost date. 

If you want your plants to be placed around your garden more controlled, you can start seeds indoors six to eight weeks before your average last frost date. These seeds require light to germinate, so it’s best to sow them lightly on the surface of the soil. Mist them with a spray bottle and keep them evenly moist until they’ve germinated. 

Your seedlings can be transplanted outside once all threat of frost has passed. While it’s true that established plants will survive over winter in very cold conditions, newly started plants and seedlings will need to be acclimated to the outdoors first. Tender young seedlings can’t handle frost at this stage. You’ll need to harden them off by slowly bringing them outdoors for longer and longer periods over a week or two. 

Once your plants have hardened off, you can transplant them. Dig a hole the same depth as your seedling’s original container and at least twice the width. Backfill it with soil and water it in well. Keep seedlings well watered until they show signs of new growth, which would indicate that they’ve been established. The benefit of direct sowing in spring or fall is that you can skip right over the hardening-off and transplanting steps! 

How to Grow

Brown-eyed Susan is very low-maintenance once established. Once you plant it, you may never need to plant it again and it will happily spread throughout your garden. 

Light

For the best blooms, these flowers prefer full sun, but they will tolerate light shade. Full sun equates to six to eight hours of direct sunlight per day. In extremely hot climates, they will benefit from afternoon shade.

The required six to eight hours of sunlight does not need to be consecutive. For example, it can be three hours of morning sun, afternoon shade, and then three hours of late afternoon sun. This can benefit plants with very hot summers. 

Water

Brown-eyed Susan seeds require consistent moisture to germinate. When starting from seed, it’s best to use a spray bottle or mister to keep the surface of the soil wet. Seedlings and transplants have moderate water requirements. You want to provide new transplants with regular water while they become established. 

These plants are quite drought-tolerant once established, especially in their second year of growth. They will generally survive on whatever rainfall you receive without supplemental irrigation as long as they receive water about every two weeks. They don’t mind drying out between waterings. Overwatering can cause fungal issues, so you may need to provide supplemental water during periods of extreme drought.  

Soil

These tough flowers can survive in a variety of soils ranging from sandy to loamy. They do prefer slightly acidic soil with a pH of 5.5-7. They can even survive in rocky and lean soils. The most important soil condition is that it is well-draining.

Brown-eyed Susan does not do well in soggy soils or standing water. For this reason, avoid planting in a low-lying area in your garden or other areas where water may collect after it rains.  

Temperature and Humidity

Brown-eyed Susans can be grown in USDA zones four through eight. Their Ideal temperatures during the growing season fall between 65-85 degrees Fahrenheit (18-29 degrees Celsius). They prefer things on the dry side and do best in low-humidity environments.  

Fertilizing

As mentioned above, these tough perennials can survive in a wide range of soil conditions, including lean soils. For this reason, fertilizing is optional, not necessary. Fertilizers can have the opposite of the desired effect.

Fertilizers too high in nitrogen can cause tall and lanky growth that results in floppy stems and droopy plants. These plants bloom profusely without the use of additional fertilizer, so it isn’t necessary at all. 

Maintenance

Regular deadheading will encourage more blooms as well as prevent self-seeding. If you want this plant to self-seed then leave the last flower heads of the season in place until the seed heads fully dry.

Then, crush them with your hands and spread the seeds. Nature will take care of the rest! Additionally, you can leave the dried seed heads standing over the winter to help feed the birds and provide structure in your winter garden. Cut them back in the spring right as new growth appears. 

Growing In Containers

Yes, this flower can be grown in containers. However, with their tall and lanky growth habit, they will require a large pot. Start with a container size of at least a gallon and size up as they grow.

Since they are short-lived perennials, you will only need to pot them up a few times in their first year of growth until they reach their mature size. Remember, they need full sun and can reach a height of five feet tall. This is important to consider when you choose a location for your pot.  

Common Problems

Brown-eyed Susan is relatively trouble-free, although a few issues can occur. Here are the signs, symptoms, and solutions for common problems. 

Lack of Flowers

If you notice a lack of flowers, then this is a sign that your plants are not receiving enough sunlight. As mentioned above, these plants prefer full sun, which equates to six to eight hours of direct sunlight per day. The hours of sunlight do not need to be consecutive, but at least a total of six hours of sunlight per day. These plants can tolerate light shade and may even benefit from it in extremely hot climates, but the general rule of thumb is to provide them with a full sun planting location. 

To remedy this common problem, you will need to move your plants to a location that receives more sun. If your plants are in containers, this is very easy to accomplish. If you’ve planted these flowers directly in the ground, then you will need to dig them up and transplant them into a new spot.  

Pests

There are not many pests that cause damage to brown-eyed Susan. However, in overly wet conditions, they can become plagued by slugs. You will notice ragged marks in the leaves that seem to appear overnight, with no known pests visible during the day. This is because slugs prefer to come out at night. 

You can use beer traps to catch slugs in the act. Simply bury a cup of beer at the soil level. The slugs are attracted to the beer. They will fall in with no way to get out. A good preventative measure is to increase airflow around your plants by keeping them clear and allowing the soil to dry out between waterings. Slugs like overly wet conditions!

Diseases

As mentioned above, poor air circulation and overly wet and humid conditions cause problems for these plants. These are also the perfect conditions for powdery mildew. It will appear as white spots of powder, generally on the undersides of the leaves. Affected foliage will eventually turn yellow and die.

If enough leaves die, then this can result in the overall plant death. There are no reliable treatments for powdery mildew, but you can prevent its spread by removing affected leaves as soon as they appear. Increase airflow around your plants and avoid overhead watering to ensure that you are not creating the perfect conditions for powdery mildew.