Black-eyed Susan: Diseases and Remedies (Explained for Beginners)

NOTE: Black-eyed Susan may be referred to as Rudbeckia hirta in this article, in fact, those are the same plants, Rudbeckia hirta is the botanical name for Black-eyed Susan.

Susans have become a garden staple because of their dependability and easy-care black-eyed Susans. Bright yellow petals and dark center disks are visible over broad ovate green leaves with a rough texture. This wildflower is native to the central United States and can be seen growing in natural areas and along roadsides in the Midwest.

It’s ability to self-seed makes it an excellent choice for wildflower gardens. After the last frost in the spring, you can plant it. It can take two to three years to reach full height, although it will flower in its first summer.

Why does my Rudbeckia hirta roots have rot?

Root rot on your Black-eyed Susan (Rudbeckia hirta) can be dangerous if left untreated. In order to keep your plant alive, we strongly suggest that you follow our advice if the signs start to show: blackened and mushy roots.
Black-eyed

Why does my Black-eyed Susan have gray mold spots?

A particular fungus known as gray mold spots spreads quickly and frequently damages flowers. This fungus is probably to blame if you see any brown (or gray) spots. If you disregard these warning signs, your plant could die.

Our Solution

The answer is obvious once you recognize the cause of the problem. Most frequently, it results from the Rudbeckia hirta being overwatered. We strongly advise you to remove the damaged plant parts, cut off the diseased roots and leaves, and then repot your plant in a new container with sterile potting soil.

Why does my Black-eyed Susan have leaf spots?

Leaf If your plants exhibit symptoms like rapid color changes in the leaves or leaves that wilt or droop, we give you all the information you need to recognize them and rescue your plants. For owners of Black-eyed Susan, this kind of illness is among the most distressing.

Why are my Black-eyed Susan leaves turning yellow?

This is probably the most common problem in the gardening world, yellowing leaves. There are 2 main reasons for this phenomenon, overwatering, or a lack of nutrients.

Whether you think your plants are getting too much water, cut back on how often you water them, and take the following measures to see if they might be nutritionally deficient:

Each deficiency produces a different yellowing on the Rudbeckia hirta in question, here’s how to spot them:

  • Magnesium deficiency starts as yellow patches between leaf veins on older leaves. Veins stay green as yellow moves from the leaf center out. Leaf edges turn yellow last.
  • Yellowing between leaf veins is another sign of iron shortage, but young leaves on plant tops and branch tips are initially affected.
  • Sulfur deficiency starts with the newest leaves, turning them yellow throughout.
  • Potassium deficiency shows itself when leaf edges turn bright yellow, but the inner leaf stays green. Older leaves show symptoms first, and leaf edges soon turn brown.
  • Nitrogen deficiency shows up as a general yellowing. Older, inner leaves turn yellow first. As it progresses, yellowing moves outward, eventually reaching young leaves, too.

Our Solution

You only need to act in accordance with the symptoms listed above. You can address a potassium or nitrogen deficiency by buying a particular soil, and a gardening store consultant will be able to advise you on how to do that. Furthermore, you can also limit how frequently you water your plants.

Is my Black-eyed Susan sunburned?

It is simple to determine whether your Black-eyed Susan (your Rudbeckia hirta) has sunburn. Your plant will change color in this instance, beginning to turn yellow or white, much like it does on us.

Sunburned

The leaves of your Black-eyed Susan can also change color in case it gets too much water or not enough light, as we saw above.

To find out if the yellow leaves have been sunburned, look at the part of the bottom that is tinted closer to the base. The yellow leaf is probably burnt and not something else if this portion stays greener.

Why are my Black-eyed Susan leaves turning brown?

A plant’s browning leaves are typically a symptom that it has been sunburned and has been exposed to excessive amounts of direct sunlight. Don’t worry; your plant probably won’t perish as a result, but its growth will be negatively impacted.

Should I leave my Rudbeckia hirta in direct sunlight?

No! Don’t leave your Rudbeckia hirta (or Black-eyed Susan) in the sun if it displays the symptoms mentioned above; that’s why it’s in such a bad situation.

Our Solution

The remedy, as said in the paragraph above, is simple: just move your plant’s Black-eyed Susan out of direct sunlight. Your plant should swiftly re-grow with this strategy and appropriate watering.

Why are my Rudbeckia hirta leaves drooping or wilting ?

In most cases, this happens when your Rudbeckia hirta lacks water. This is especially the case for large plants, naturally they need more water than others.

Drooping

You may quickly determine if your Rudbeckia hirta plant needs water by under-weighing its pot; if it seems light, the soil and roots are probably fairly dry and require water.

Our Solution

If the soil in your plant’s pot is completely dry, you will need to start by moistening it so that the roots will also benefit from the water. A common mistake is to drown the Black-eyed Susan right after a dry period thinking that it needs a lot of water.

This is true, but the easiest way to end it is to give too much water at once. Instead, you should water the soil properly, returning to a peaceful watering rhythm.

Caring Tips for Rudbeckia hirta

Water Occasionally

Water is essential to the survival of your plant, however, it is important to balance the rate of watering. As we explained above, overwatering could have fatal consequences for your Rudbeckia hirta.

You can tell if your plant needs water by touching the soil; if it still feels damp, it’s usually preferable to wait a few more days.

Always keep temperatures stable

It is also a good idea to keep your Rudbeckia hirta at a stable temperature (especially if it is kept indoors!). At GreenShack, we generally recommend staying in the 65 and 85 degrees F range. Of course, do not place your Rudbeckia hirta near a source of hot (or cold) air such as A/C units, radiators or the like.

Keep your Black-eyed Susan Dust-Free

This one concerns indoor plants, just like on your furniture, dust is also deposited on the leaves of your indoor plants, the problem is that it can prevent them from receiving the necessary light, this would slow down (or even stop) the photosynthesis process, and eventually, they would lose their colors.

For your Black-eyed Susan, this would be a true descent into hell, and it would also appease the pests.

To remove the dust from the leaves of your plant, take a microfiber cloth and gently rub the leaves. You can wet the cloth to make it easier to remove the dust, but never use corrosive products (such as rubbing alcohol!)

Keep drainage in mind

If you have a tendency to overwater, you should be mindful of your drainage, and if they don’t already have them, we suggest selecting a saucer and a pot with drainage holes.

You can add volcanic rocks (or any other pebbles with holes) to the bottom of your pot in the interim if your pots don’t already have holes in them. This will help to form a channel so that the water doesn’t pool there for too long (preventing the rot of the roots!).