The main reason why Crocosmia dies is because of overwatering, which causes the yellowing of the foliage. Gladiolus rust is a disease that causes browning of the leaves. Yellowing of the leaves may also occur due to nutrient imbalance.
Crocosmia is also called Montbretia or ‘Coppertips’ plant. This plant is grown in gardens for its beautiful flowers. The blossoms are brightly colored and the foliage is sword-shaped.
These blossoms form a bunch and stay on the plant from mid-summer through mid-fall. This plant is easy to grow, in some cases gardeners face issues.
Why do Crocosmia leaves turn brown?
Crocosmia leaves turn brown due to a disease called Gladiolus rust. Brownish-black or Brownish-yellow spots are seen on the leaves in the case of Crocosmia rust, a fungal disease. Yellow spots turn brown eventually in the case of Spider Mite infestation.
Spider mites
Spider mites are relatives of spiders and they infest a great number of plants. Two-spotted spider mites affect Crocosmia. These are tiny pests that you can’t even see with the naked eye.
Spider mites if present in large numbers cause the foliage to brown and dry up. If you don’t fix the issue early on, the plant fails to flower.
To fix:
- Try to dislodge the mites with the help of a garden hose.
- You may want to follow the above with the application of Neem oil.
- If the infestation is severe, you can spray the infested plant with Insecticidal soap. Spray the plant once more if spraying once doesn’t fix the issue.
- Cut off and remove dead leaves to prevent further infestation.
Gladiolus rust/Crocosmia rust
Gladiolus rust is caused by a fungus. Crocosmia doesn’t usually get affected by this fungus but it can happen in some cases.
You’ll see brownish black or brownish yellow spores on the leaves. Such signs are sometimes seen on the flowers too.
Gladiolus rust is caused by low light and low humidity. There’s no treating this disease once it attacks a plant.
You may want to treat plants prior to infection. Spray fungicides like Copper spray or Sulfur powder in early spring and continue to spray throughout the growing season. This will prevent the infection for sure.
Crocosmia brown leaves drought
Crocosmia grows in driest soils but it needs some water to survive too. Make sure the soil is well-draining but water it occasionally.
Give your plant the required amount of water in the growing season to prevent drought.
Why does my Crocosmia fall over?
Gladiolus/Crocosmia falls over as it spreads vigorously. This happens when the Gladiolusnplant becomes dense and there is no place to spread.
Crocosmia is reputed to spread vigorously. It spreads so fast that it becomes invasive often. It spreads via rhizomes.
How to stop Gladiolus from falling over?
Stop Gladiolus from falling over by dividing the plant and giving the plant room to breathe. Thin out the plant however possible.
You can put some kind of support in the flower bed near the plant. Bend some old wire hangers to make your own wire hoops to support the plant.
How to Divide Crocosmia?
Dig to a depth of 12 inches and take out the corm. Use two garden forks back to back to take the corm out without damaging them much.
Discard shriveled or diseased corms and use the healthy ones.
When to divide Crocosmia?
Divide Crocosmia in the spring after flowering. You need to divide your Gladiolus once every three years. You can keep the plants healthy by doing so.
Don’t divide the Crocosmia till the last frost has passed. Crocosmia flowers properly when the corms are in clumps, so don’t divide the Gladiolus too often.
Why Crocosmia leaves yellowing
Crocosmia leaves turn yellow due to Chlorosis. Chlorosis is seen in plants that don’t get the required nutrients. Crocosmia leaves turn yellow when it gets more water than required.
Overwatering
Overwatering is probably the most common reason why the foliage turns yellow. Crocosmia are drought-tolerant plants.
This is the reason why they hate waterlogged conditions. Always water these plants consciously. Water only when the plant needs some.
Check the soil with your fingers and water only when the top 2 inches of the soil goes dry. Make sure the soil has good drainage.
Nutrient Deficiency
When the plant couldn’t absorb the essential elements it shows the above signs. This happens either when the soil lacks nutrients or when the plant couldn’t absorb them even when they are present.
Send the soil for a test in your local laboratory. If the soil lacks Potassium, Nitrogen, or Phosphorous, it’s time to act quickly.
You don’t need to add fertilizer or any kind of supplement. Crocosmia doesn’t need all that. You just need to fix the soil. This usually happens due to pH imbalance.
pH
pH imbalance may cause this issue with nutrient absorption. Crocosmia thrives in slightly acidic soil. If the soil is alkaline the plant fails to absorb essential nutrients.
- You can add Aluminium sulfate to the soil to decrease the pH.
- If your flower bed is small you can add sphagnum peat to it. It efficiently reduces soil pH.
How do you cut back Crocosmia?
Trim back the leaves that are dead or brown. Hold a clump of dead leaves and cut them close to the ground. You can wait for the leaves to die and then a gentle shake can drop the dead leaves.
When to cut back Crocosmia?
Cut back Crocosmia in the spring for the best results. The new leaves and corms would’ve developed fully by now and it’s safe to cut the plant back.
After the plant is done with flowering, it needs to assimilate some nutrients in the corm. Gladiolus is done with food assimilation by early spring.
When to cut back Crocosmia UK?
Wait until early spring to prune your Crocosmia in the UK. You can prune your Gladiolus around March to help the new growth.
Why won’t my Crocosmia bloom?
Crocosmia won’t blossom for a number of reasons. Ideally, it should give out tons of brightly colored flowers. Let’s know the factors why your Crocosmia fails to flower.
- Too much fertilizer.
- Too much shade.
It’s just normal sometimes. It may flower abundantly one year and show no blossoms the next year. If you want to know why Crocosmia doesn’t flower, read our article.