Everything You Need to Know
About Black Eyed Susan

By Beth Krietsch

With their signature golden petals and dark, cone-like centers, Black Eyed Susans are an iconic flower found in gardens across the country during the summer months. Growing in zones four through nine, they’re fairly hardy perennials that grow quickly, can handle varying weather conditions, and are simple to care for.

Besides being loved for their bright colors, Black Eyed Susans are also popular cut flowers that make the perfect bouquet. They don’t attract many pests aside from the occasional aphid or slug, but are a favorite of butterflies, bees, and ladybugs. This native, North American wildflower has been used as a medicinal herb by some Native American tribes to boost the immune system.

A few favorite Black Eyed Susan varieties

Formally known as Rudbeckia, Black Eyed Susans come in many varieties. Here are a few you may come across:

  • Indian Summer (Rudbeckia hirta var. hirta)These drought-tolerant annuals have a classic look and grow somewhere between three and four feet tall. Indian Summer petals are golden-yellow and can grow up to nine inches across.
  • Gloriosa Daisy (Rudbeckia hirta)These produce large flowers and can bloom in a number of colors, though yellow and orange are the most common. These perennials will usually grow somewhere between two and three feet tall.
  • Clasping Coneflower (Rudbeckia amplexicaulis)These annual, yellowish-orange flowers grow between one and two feet tall. They are notable for their delicate and somewhat cone-like shape, with oblong leaves that seem to clasp the stem. Clasping Coneflowers are also drought-tolerant and bloom in the spring and summer.
  • Sweet Coneflower (Rudbeckia subtomentosa)These perennials can grow up to five feet tall and have a long blooming period. They grow best in late summer or early fall.

Gloriosa Daisy Rudbeckia hirta

Indian Summer Rudbeckia hirta var. hirta

How to plant Black Eyed Susan

Black Eyed Susans love sun, and most varieties thrive in full sunlight, though a few varieties also do well in partial shade. When deciding on a Black Eyed Susan variety, consider whether you want flowers that pop up year after year or bloom for just one season. Some Black Eyed Susans are annuals, whereas others are perennials or biennials.

Perennials, such as the popular Sweet Coneflower, will make an appearance year after year. Annuals can be planted each season, but they may pop up on their own after leaving seeds behind in the fall. This is common, as most varieties of Black Eyed Susan are self-seeding.

Here are a few tips to keep in mind as you start gardening:

  • Farmers Almanac recommends waiting until the soil hits 70 degrees to plant your Black Eyed Susans. This will likely fall somewhere between March and May, depending on your location.
  • For the healthiest flowers, find a spot with full sun, but note which varieties will need partial sun.
  • Make sure the soil will drain easily—Black Eyed Susans don’t do well in muddy soil.
  • Most flowers will spread out over 18 inches as they grow, so leave space between seeds when planting.

Caring for your Black Eyed Susan

One benefit of Black Eyed Susans is that they don’t require much care. Here are some additional factors to consider to maintain happy and healthy Black Eyed Susans.

  • Black Eyed Susans are fairly drought-tolerant, but you’ll still want to water the base of the plant weekly, or more frequently if they look dry or stressed. The soil shouldn’t be completely dry.
  • At the same time, be careful not to overwater. Black Eyed Susans are known to rot when they’re in soil that’s overly wet and muddy.
  • Divide your Black Eyed Susans every four years in the fall to keep them healthy. To do so, remove an entire section from the ground and divide it into a number of smaller sections, maintaining a healthy root system for each. After, replant them in an area that gets plenty of sunlight.
  • As the flowers dry and wither, whether at the end of summer or throughout the season, you can use pruning shears to remove them. This can help prolong the plant’s blooming time.
  • Alternatively, leave the seed heads on the plants after the growing season to help Black Eyed Susans reseed. The seed heads are also a nice food source for birds.
  • Dark brown spots on the leaves that expand in size could be a sign of a fungal infection called rudbeckia leaf spot. To prevent the disease from growing and spreading into the next season, you’ll want to remove diseased leaves sometime in the fall after the summer growing season.
  • If you notice a number of small green bugs crawling on your Black Eyed Susans, you may have an aphid problem. This is rare but occasionally happens and can be treated by spraying insecticidal soap.

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