Tiger lilies are fierce and beautiful flowers to include in any yard or garden, and they’re a popular choice because they can thrive in sunlight or shade. Typically, these blooms are a vibrant orange with black spots, but the blooms can also be yellow or red. Sometimes, the color of the flowers may even change, as does the color of the foliage!
Tiger lily blooms may turn yellow due to a genetic reversion to the genes of the dominant parent. The leaves may turn yellow due to overwatering or underwatering, diseases or pests, or because it is the end of the growing season.
In the rest of this article, I’ll discuss in detail why your tiger lily blooms or leaves might be turning yellow. If this is an issue you’re experiencing and you’re confused or concerned, this is the article for you!
Why Tiger Lilies Turn Yellow
There are several reasons your gorgeous tiger lilies are turning yellow, so it is a process of elimination. If your plant is healthy and abundant, and the color change is the only problem, the cause is likely genetic.
Genetic Reversion Causes Tiger Lilies to Yellow
If your tiger lily bloom turns yellow, this may result from genetic reversion, as many tiger lilies are hybrids with complex parentage.
Typically, if your tiger lilies bloom and they are orange with black spots, this is what they will look like the following season, too. However, because tiger lilies bought and planted are typically hybrids, the plant may revert to the dominant gene and change color.
This genetic reversion could cause a tiger lily to go from orange or red to yellow over time. However, this is unlikely, and it is far more likely that you’ll notice the foliage of your tiger lily turning yellow.
If your tiger lilies are yellowing along with signs of ill health such as wilting or drooping, then you should explore the following common reasons why this occurs.
Overwatering or Underwatering
Tiger lilies need approximately one inch (2.5 cm) of water per week, which may increase during dry periods. Generally, the soil around your tiger lilies should be moist but not saturated. If your tiger lily doesn’t get enough water, the plant will become dehydrated, and the leaves will begin to shrivel, turn yellow, and die.
You risk exposing the roots to root rot if you overwater your tiger lily. Root rot is the growth of destructive Pythium, Phytophthora, Rhizoctonia, or Fusarium fungi on your plant’s roots. The fungi in moist and warm conditions cause many issues, including:
- Leaf yellowing
- Stunted growth
- Rotted roots
- Rotted bulbs.
To avoid this problem, plant your tiger lilies in well-draining and well-aerated areas so moisture doesn’t gather and create a pleasing environment for fungi.
To ensure that your tiger lilies aren’t in soil that is too wet, you can use a soil moisture meter to measure how much moisture is in the soil.
Disease and Pests
Another reason tiger lily leaves may start to turn yellow is because of an infestation of disease or pests.
The Mosaic Virus
The primary disease you need to be concerned about is the Plantago Asiatic mosaic virus. This disease is a potexvirus of Alphaflexiviridae, a family of pathogenic viruses that affect plants.
Tiger lilies are particularly susceptible to this disease and can quickly spread it to other plants if you don’t catch it soon enough.
In fact, one of the main reasons gardeners choose to avoid tiger lilies is the mosaic virus. One of the main symptoms of the mosaic virus is yellow streaks on leaves, so if you start noticing that your leaves are yellowing in stripes, this disease may be the reason.
There is no way to cure a plant of a mosaic virus once it is infected, so you need to focus on prevention instead.
Aphids are tiny insects that not only damage your lilies but pass the mosaic disease onto lilies. To prevent aphids, you can release ladybugs in your garden. Ladybugs will feed on the aphids without damaging the tiger lilies.
You can also spray neem oil on plants to kill aphids.If you would like to explore your options on how to get rid of aphids, check out my article on daylilies: How To Get Rid of Aphids on Daylilies (Complete Guide)
Weeds can also serve as hosts for mosaic viruses, so make sure you stay on top of your weeding. One way to prevent weeds from growing is to use organic mulch around the plants. Beneficial insects such as crickets and carabid beetles like living in organic mulch, and these creatures eat weed seeds.
If you notice signs of the mosaic virus on your plant, you’ll need to eradicate the plant and destroy it. Then, disinfect all the tools you used to cut down the plant, as the virus may have transferred to the tool.
Red Lily Beetle
In addition to aphids, another pest you should keep an eye out for is the red lily beetle. These beetles are more common in Europe but are becoming more of a problem in the eastern and northern United States.
They are bright red and a quarter of an inch long, and they can wreak havoc on tiger lilies, including damaging the stems so much that the leaves start to yellow and die.
If you notice these pests, you can hand-pick and crush them and their eggs. You can also use an insecticide that contains neem. Neem is effective in killing larvae and helps control the disease.
The End of the Growing Season Causes Lilys to Yellow
The final reason your tiger lily leaves may turn yellow is simply the end of the growing season. As summer turns into fall, lily plants begin to die back, and the leaves start to yellow. In this situation, the change is not a problem but merely a symptom of a natural process.
Lower leaves will be yellow first, and the yellow color will eventually creep up the plant and spread to stalks. As part of your pruning process, you should cut back dead leaves and stalks close to the ground, but you should wait until the end of fall as yellow leaves and stalks are still preparing nutrients for the next season’s growth.
You can cut them down once you’re confident that the stalks and the leaves are completely dead. This process helps prevent the spread of diseases, reduces pest populations, and allows the plant to direct its energy and resources to new growth.
When the next growing season comes around, you can divide your tiger lilies if you’d like, or let them be and grow as is.
Tiger lily blooms may turn yellow because their genes eventually revert to their dominant parent, which may have been yellow. More often, the leaves of a tiger lily plant will turn yellow due to too much or too little water, diseases, pests, or simply because it is the end of the growing season.