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Spotted laurels are known for being quite disease-resistant. These resilient plants grow well in pots and gardens, making them a top choice for those without a green thumb. However, that doesn’t mean they won’t experience blackened leaves, fungal spores, and other common plant issues.
The Primary cause of black leaves on spotted laurel plants is bacteria or fungi. These spots can spread to the stems and roots, causing the plant to wither and wilt. Snip the black leaves and use a copper-based fungicide to prevent the disease from coming back.
In this article, you’ll find out why your spotted laurel has black leaves, what you can do about it, and how to prevent the black spots from coming back.
What Causes Black Leaves on a Spotted Laurel?
Black leaves on a spotted laurel can be the result of root rot, fungal infections, and pests. Furthermore, waterlogged or excessively cold roots will undoubtedly damage and blacken a spotted laurel’s leaves.
Aucuba blackening (the name for black leaves on a laurel) often occurs during frigid, damp weather. These conditions prevent the plant from aerating properly, and they also can’t absorb as much moisture when they’re freezing cold.
Other potential causes of black leaves on a spotted laurel include:
- Various fungal diseases, mildew, and mold
- Extreme heat burning through the leaves
- Dry soil that dehydrates the leaves and stems
- Spreading bacteria from nearby plants
If you notice any of these issues on your spotted laurel plants, proceed to the next section for a handful of solutions.
How Do You Treat Black Spots on Spotted Laurels?
To treat black spots on spotted laurels, follow these steps:
- Prune the diseased leaves and stems. Snip each of the infected leaves off of the spotted laurel (source). You can also remove the stems from the base of the plant if they’re infected.
- Spray the plant with a copper-based fungicide or an all-natural fungicide (neem oil is fantastic). Copper naturally repels bacteria, fungi, and many other unwanted plant illnesses. Furthermore, it doesn’t add any unwanted chemicals into the air. Make sure all nearby plants can be treated with copper without wilting, too.
- Check the moisture two inches below the soil. The easiest way to know if your spotted laurel is waterlogged or drowning is to poke your finger into the dirt. If it’s soaked and mushy two inches below the surface a day or more after watering the plant, there’s too much moisture. If it’s dry and crumbly, there’s not enough water. See What Are The Signs Of Overwatering Plants?
- Dry or hydrate the soil based on the results above. Lime is one of the quickest treatments to dry the soil. Make sure you don’t add too much or it’ll strip the water from the plants, too. If the soil is too dry, water it until the soil feels hydrated and moist at least two inches below the surface.
- Keep your spotted laurel out of direct sunlight if the leaves are burning. Too much sunlight will burn your plant. Spotted laurels need several hours of daily sunlight, but too much direct heat can blacken or brown the leaves. You’ll notice this is the cause if the leaves feel dry and crumbly (not powdering or moldy).
You could use this natural pesticide spray (link to Amazon) to remove mildew, fungi, bacteria, pests, and other causes of black spots on a spotted laurel. It’s made with enriched essential oils, allowing you to use it indoors or outdoors without adding VOCs or other toxic chemicals into the air. You can apply it directly to the leaves, stems, or soil.
Tips To Prevent Spotted Laurel Diseases
If you want to prevent spotted laurel diseases, keep your plants away from pests, excess moisture, and other plants with fungal and bacterial diseases. These plants are quite resistant to most plant diseases and discolorations, but overwatering and improper pruning can make them vulnerable.
Here’s a quick list of preventative suggestions:
- Sanitize your shears and gloves to prevent the diseases from spreading. Fungal infections can spread between plants, especially when you use the same pruning tools (source). It’s also a good idea to wash your gardening gloves if you use them to remove black leaves from the spotted laurel.
- Don’t drench the soil around your spotted laurel. Soaked soil is the primary cause of root rot, which can lead to black leaves. You should be able to poke your finger into the soil without reaching mushy dirt, as mentioned earlier. Automatic watering globes work perfectly for spotted laurels.
- Improve the aeration and drainage of the soil to prevent it from waterlogging the roots. You can use soil aerators or remove clay and other dense materials from the soil by hand. Spotted laurels need plenty of water and oxygen, and they won’t get enough if they can’t drain properly.
- Fertilize your spotted laurel to encourage new growth. It’s important to balance the clipped, black leaves with new, vibrant leaves. You can use various natural fertilizers, mulch, or compost.
- Dispose of the diseased clippings (don’t use them in mulch or compost). Plant diseases spread rapidly, even if the leaves decompose. Throw the clippings into a bag, seal them, and throw them away.
Thankfully, your spotted laurel can fully recover from the vast majority of plant diseases (including blackened leaves, roots, and stems).
Proper drainage and fertilization can make a massive difference. You can also bring potted plants indoors if it gets too cold outside, which could prevent the leaves from darkening.
While most plant diseases are treatable, it’s important to get rid of the black leaves on your spotted laurel as quickly as possible.
Not only will it prevent the disease from spreading, but it’ll also ensure your spotted laurel lasts much longer.