Calla lily leaves can turn brown if the plant is getting too much water, too much hot, afternoon sun or are being attacked by pests. Too much water can also be the cause of browning leaves as the roots can rot and the plant leaves can droop. Plant calla lilies in well-draining soil and fertilize in spring with pelleted chicken manure.
This article will explore the top causes of calla lily leaves turning brown and so you can work out what it is for your plant. Each problem will come with an easy solution and then we will how explore how to prevent this problem from happening again.
Top reasons why calla lily leaves will turn brown
Here are the top reasons why a calla lily plant’s leaves turn brown and how to fix it.
1. Too much water
Calla lily plants that are overwatered will develop brown and drooping leaves. The excess water can rot the root or burst the cells in the plant’s leaves. The leaves can also turn yellow as the nutrients are washed out of the soil.
Damaged roots will not be able to absorb the nutrients the plant needs causing it to suffer, turn yellow and then brown.
The easy solution to this problem is to reduce your watering schedule to once 1-2 times per week in spring and. While watering each week in summer might be necessary you should always check the soil first to see if it is moist.
You only need to water the plant if the soil is dry 2 inches down. Water the plant deeply and let it dry out between watering.
2. Cold weather
Calla lilies love warm weather and in cool climates they will die back over fall and winter. Their leaves will turn brown, and the stems will die back returning the nutrients to the bulb. The rhizomes will survive in the ground if the weather does not drop below too far below 65 degrees Fahrenheit.
You can dig the rhizome up and store them in cocopeat in your garage. If your weather is mild over winter, you can leave them in the ground and they will survive over this time.
3. Poor draining soil
Calla need free draining soil to avoid their rhizome and roots from rotting. Heavy clay soils will hold too much water for calla lilies and can cause root rot and brown leaves.
The easy way to solve this problem is to mix through a large amount of organic material through the soil before planting. Choose an aged manure like cow or chicken and mix it through the soil with compost. This will help to feed the plant and let the excess water drain out well.
4. Too much sun
Calla lily can develop brown leaf tips if they are expose to hot, afternoon summer sun. If you live in hot climate, the afternoon sun will be too much and can burn their leaves. These plants love part shade in hot climates.
To keep your calla lily protected move any potted plants into a position that gets afternoon shade. You could also plant calla lilies in the ground near other plants that provide afternoon shade. They make a great border with the protection of nearby shrubs.
5. Pest attack
Caterpillars, slugs and snails can chew on calla lily leaves creating holes and brown marks on the leaves. Sap sucking insects like aphids, spider mite or thrips can also cause damage to the leaves causing them to turn brown or yellow.
Set a beer trap for snails and slugs or sprinkle diatomaceous earth, crushed egg shells or used coffee grounds around the plants. This will stop snails and slugs from reaching the leaves and will not harm the plant. Aphids and other sap sucking insects can be treated with neem oil or washed off with a quick blast of water.
6. Frost damage
Calla lilies hate frost so they can develop brown leaf tips if they get exposed to it. Frost damage can cause the leaf to brown but if the frost is heavy, it can kill the whole plant. Small calla lily plants are particularly susceptible to frost damage so keep them protected by planting them near a masonry wall, bringing them under cover if you suspect a frost.
7. Not enough water
A calla lily plant that is not given enough water will turn brown and crispy on the leaf edges.
To tell the difference between overwatering and underwatering it is important to check the soil. Plants that are not getting enough water will have dry soil at least 2 inches below the surface. Overwatered plants can have mold growth on the surface of the soil.
A calla lily plant that has been underwatered over a period can develop hydrophobic potting soil. This is where a film will coat the soil particles and the water will flow straight over the soil. The plant will not be able to absorb the water and the leaves can brown on the tips.
Water the plant regularly and check the soil to see if it is dry. It is best to deep water the plant less often and water it when the soil is dry 1-2 inches below the surface. Plants growing in pots will benefit from repotting with fresh potting soil to add back organic matter and so the soil can hold water well.
8. Fungal leaf spot
Fungal leaf spot can occur on calla lily, particularly if soil is splashed onto the leaves. Fungal diseases can turn the leaves brown, red (rusty color) or black in spots eventually causing the leaf to die.
This can be caused by overwatering, transfer of disease from other plants or splashing of soil from the ground or pot up to the plant leaves. Water at the base of the plant and surround it with mulch to prevent soil from getting on the leaves. This can help to reduce the chance of fungus transfer and infection.
For more on how to grow calla lilies, check out this article below.
How to treat Calla lilies with brown leaves
Here are the simple steps to follow to solve and prevent the problem of brown leaves on calla lilies.
1. Cut off the affected leaves
Start by removing the brown leaves from the plant. Brown or damaged leaves won’t grow back and this can be the most effective way to remove any fungal disease or leaf spot.
2. Slow down your watering
If you suspect that overwatering is the problem, water the plant only when the soil is dry 2 inches below the surface.
3. Water in the morning
For both outdoor and indoor calla lily plants, water them in the morning. This will allow the soil to dry out well throughout the day and reduce the risk of root rot. This will also reduce the chance of fungus growing on the leaves as they dry out faster than watering at night.
4. Water at the root zone and not the leaves
When you water calla lily, pour the water using a watering can or sprayer nozzle at the root zone. This will help to prevent water from sitting on the leaves which can encourage fungus or bacterial growth.
Mulching the plant will also help as this can prevent soil from splashing which can carry fungus. You can even mulch pots using a bark mulch to help prevent brown leaves.
5. Use a good quality potting soil
Repot overwatered plants into a good quality potting soil. This will help the plant to get the water and nutrients it needs. If you are planting calla lilies out into a garden bed, improve the soil first with compost and aged cow manure. The water will drain well and these will gently feed the plant.
Add a slow release fertilizer in spring, using pelleted chicken manure for outdoor plants and a slow release indoor fertilizer for indoor plants.
6. Don’t leave them on a pot tray
Avoid leaving potted plants in a pot tray with water to prevent rot and browning leaves. Pour out excess water from these trays or water the plant outdoors or in your laundry sink to allow it to drain before putting it back on the tray.
7. Move the plant into afternoon shade
For potted calla lilies or those newly planted they will benefit from protection from the hot afternoon sun. If the calla lily is growing in the ground you can surround it with taller plants like clivias to create some shade.
8. Mulch the plant with bark
It is important to mulch your calla lily with bark to stop water and soil from splashing on their leaves and to help the soil to hold water for longer. A 2 inch layer of bark mulch is perfect as it will help to avoid any soil washing away and feed the soil bacteria and worms improving the soil over time.
Calla lily leaves turning brown | Summary
Calla lily leaves can turn brown if the plant gets too much water, too much hot, afternoon sun or is attacked by bugs. Make sure it is planted in good quality potting soil or in improved soil with compost mixed through. Only water your calla lily when the soil has dried out 2 inches below the surface.
To find out why calla lily leaves turn yellow, check out my article here: Calla Lily Leaves Turning Yellow | 5 Easy Solutions