Grow Rudbeckia (Black-Eyed Susan) Outdoors

Last Updated on February 15, 2022 by Real Men Sow

Rudbeckia, also known as Coneflowers or Black-eyed Susan, comes in many varieties and their flowers are yellow/orange with a dark center. They make great garden plants and flowers from the end of summer until the first frost.

They require well-drained, moist ground throughout their entire growing season. The plant can grow in any type of soil, from clay to sandy soils, and is easy to maintain if the soil is kept moist. Rudbeckia grown in containers are very successful and are well-suited for the UK.

How Tall Does Rudbeckia Grow?

Rudbeckia can grow up to 75cm/30in high. The yellow/orange flowers appear mid-August through last October. However, they do not smell. The flowers can be cut and their leaves die in November.


Planting Rudbeckias (Black-Eyed Susan) In The Garden

  1. You should choose a position that is sunny or partially shaded. You should choose a spot where the soil is not too dry but still moist.
  2. Add lots of compost to heavy soils or that is difficult to drain. Dig it in.
  3. You can plant it all year long as the soil isn’t frozen and you water well when it gets dry. Potted Rudbeckias should be planted between March and April and September through October.
  4. Dig a hole twice as wide as the root ball. Add a few drops of blood, fish, and bone to the hole and then work it into the ground.
  5. Fill the hole with soil to the same depth as the pot. Firmly but gently fill the hole around the root ball. To settle the soil around the root ball, water well.
  6. Plant more than one plant at 50 cm / 18 inches apart.

How To Care For Rudbeckia

Rudbeckia Fulgida needs moist, but not too dry soil. Give them water if they are left dry for a prolonged period.

They need very little to no food. They will thrive on a healthy diet of fish, bone, and blood. You should not give your flowers nitrogen rich fertilizers. This will encourage leaf growth at all cost to the plants.

Deadheading the flowers regularly will encourage more flowers and prolong their life span.

Growing Rudbeckia in Pots and Containers

Rudbeckia Fulgida ‘Little Goldstar’ is compact and therefore, recommended to be the variety grown in containers. They prefer moist, well-drained soil and therefore need regular watering. Good drainage holes are also a must in any container or pot. They will grow in any multipurpose potting soil.

The first two weeks following the planting, don’t feed the plant. Next, feed your plants with a general liquid feed once every three to four week.

The smallest container for plants is a 45cm/18in diameter. A larger container will make the plant happier and will need less watering. It is okay to have a container 30 cm / 12 inches deep. However, it will require less watering the deeper the container.

Dividing Rudbeckia (Black-Eyed Susan)

After three to four years, your Rudbeckia Fulgida flowers start to drop. This is best done in spring, but April is also a good time. You can also divide them in autumn.

Make sure to water the plant the previous day before you divide it. Cut all foliage to a distance of approximately 15cm/6in from the root ball.

With a fork, remove the root ball and keep as many roots attached as possible. It’s then easy to cut the root ball into equal pieces. You can either take it apart with your hands, or you can literally cut it with a hacksaw.

Place each part in its new position and water well. Place them 50cm apart / 18in apart. Don’t feed the plant until it has new leaves.

Pests and Diseases 

Rudbeckia Fulgida is a strong-growing plant that is rarely attacked by pests. They can sometimes suffer from leaf spot, but this is rare.

Leaf Spot on Rudbeckia

Dark spots appear on the leaves as a sign of this problem. The affected leaves eventually fall off, and worse cases can cause severe damage. Recent research shows that most of the time, damage is not caused by disease but rather by damp, humid, and/or cold conditions.

If the damage is not severe enough, you can remove the spotted leaves and then burn them. If the damage is severe, you might have to accept that your Rudbeckia Fulgida plants are too wet.

Sometimes, leaf spot can be caused by watering by hands. It can leave marks if water falls on leaves. Watering the soil, and not the leaves, is the best solution.

Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.