Lily Pests and Diseases – Tips to Protect Your Plant 

Lilies are popular flowers that are often in full bloom in spring and summer. You’d probably see them in many gardens or in nice little pots decorating porches. Taking care of these beautiful plants includes warding off lily pests and diseases that could wipe them out in a few weeks. 

In this article, we’ll take a closer look at 7 of the most common lily pests and diseases. In addition, we prepared a practical guide for treatment and prevention. This should keep your plants happy and thriving throughout the season. 

Common Lily Pests and Diseases

There’s a whole array of flowers that we know as lilies, plus a bunch that looks so similar to these colorful blooms but aren’t technically lilies. These plants belong to the genus Lilium, which is the parent of around 100 species of lilies. 

These gorgeous perennials decorate our houses, public spaces, restaurants, and vases. Florists love them as they work great in party arrangements, wedding bouquets, and as valuable gifts on special occasions. 

Unfortunately, these lovely lilies are also easy targets for plenty of pests and pathogens. And once they fall prey to these parasites, they soon look sick, wilted, and yellow. If they’re left untreated, they could deteriorate irreversibly. 

Regular inspection is the best approach to keep that unsavory outcome at bay. Once you spot a bug, a discoloration, or an odd look in the plant, you should take quick action to treat the plant. Naturally, proper treatment depends on what exactly is causing the problem.  

This would be much easier if you can identify what you’re looking at.  

  1. Viral Infections 

Lilies are prone to get infected by several kinds of viruses of varying ferocity. Among them are the mosaic virus, tulip breaking virus, tomato spotted wilt virus, in addition to a number of other ailments. 

These viruses are common in vegetable gardens, and then they gain their transmissibility from plant proximity as well as insects.

There are some particularly annoying viral infections, like the spotted wilt, which is transmitted by thrips. It presents as visible yellow or white spots right below the flower. Early treatment is paramount to controlling this pathogen.   

  1. Fungal Infections 

There’s a long list of fungal spores that cause the lily roots or stems to rot. Most of them are caused by excessive irrigation and humidity. Standing water is the perfect medium for these organisms, and once they populate the soil sufficiently, they spread their presence inside the plant. 

The roots go bad first, so if you inspect them at that phase, you’d notice that they’re soggy with dark rotting patches. If left untreated, the fungus affects the stem and leaves as well. 

Botrytis and Botryotinia fungi are among the nastiest pathogens, and they’re often the ones causing grey rot. In addition, Fusarium, Phytophthora, Pythium, Rhizoctonia, and rusts can also affect potted or garden lilies. 

  1. Aphids 

Aphids are tiny oval bugs with a voracious appetite. They develop from a baby nymph to a reproducing adult in about one week. And once they start procreating, each one can produce 80 little ones. Thus, a whole colony of aphids can overpower a plant in a very short time. 

The telltale sign of an aphid infestation is a waxy white material all over the leaves and stems. This honeydew-like substance is a magnet to a dark fungus that affects the leaves badly. Quite often, the leaves curl up and the plant ceases to grow.   

spider mite webs on foliage
  1. Spider Mites 

Web spinning mites are quite the common sight in gardens. They aren’t technically insects, as the various mite species belong to the arachnids class. This is where tarantulas, scorpions, and black widows belong.   

Interestingly, they behave in a manner that’s quite similar to the larger spiders, including making silky webs and sucking the life out of their prey. 

Spider mites might be too tiny to notice, but they collectively spin large webs on the leaves, and these are hard to miss.  

  1. Thrips 

Thrips are tiny flying insects that feed on the cell sap of plants. They’re fond of fruits, vegetables, and flowers. And once they find a pleasant spot, they multiply enthusiastically. 

The trail they leave behind them is the easiest way to spot the thrips’ presence. The manner of feeding that they practice causes immediate discoloration of the leaves and other parts of the plant. A unique effect is a silver color that the foliage turns into after a particularly big feed.  

  1. Leaf Miners 

Leafminers are types of flies with black bodies and yellow markings on their bellies. They are more abundant during the warm season, where they ramp up their feeding and procreation to the max. 

An adult leaf miner easily makes a hole in the leaf of a plant and sucks up its sap. After the feast is done, the holes become clear white, and that spotting is one of the signs that point at the miners. 

There’s another surefire sign though, and it’s caused by the maggots of leaf miners. The adult fly punctures a leaf and lays its eggs inside it. As they grow, they move around the foliage leaving a winding white trace. It’s impossible to get wrong.  

Close-up snails
  1. Slugs and Snails 

Slugs and snails seem to exist wherever there’s a patch of vegetation. They eat anything they can get their slimy little tongues on but especially leaves. We listed both of these creatures together despite their differences in appearance. As a matter of fact, they’re both mollusks, so that makes them close cousins.  

These pests often live close to the soil, so they’d take advantage of any fruits that grow at that level. Tomatoes, cucumbers, and strawberries are absolute favorites. 

Slugs and snails are nightcrawlers that operate with great discretion. The only reliable telltale sign they leave is a shiny sticky trail.  

Treating an Infected Lily 

There are 5 basic steps to treat an infected lily. It would be best to identify the pest or pathogen causing the plant’s problems. But even if that’s not feasible, these measures are usually effective on a wide range of plant issues.

Step 1: Use a Mild Organic Insect Repellant. 

Step 2: Cut off the infected leaves, put them in tight plastic cases, and dispose of them according to the local regulations.

Step 3: If the infestation is still there, use a more powerful insecticide

Step 4: Sterilize all your gardening tools after each use. 

Step 5: you might need to change the pots and the soil, especially in case of root rot and other fungal infections.  

How to Ward Off Lily Pests and Diseases 

Prevention is the best treatment, and to that end, we do our best to ward off pathogens, parasites, and bugs. 

Here are some tips that would help in keeping your garden healthy and thriving. 

  • A healthy plant is more capable of resisting infections and infestations. So make sure your plant has enough water, sunlight, soil nutrients, and fertilizers.
  • Avoid letting the soil become waterlogged. Efficient drainage is essential to keeping off fungal growth.  
  • Use a diluted mix of neem oil and water to spray the plants every week. This is known to deter several types of bugs. 
  • Wash the leaves and stems every once in a while with a garden hose. This is like giving the plants a refreshing shower, and it also shakes off a number of pests.
  • Remove any weeds sprouting around the plant. They might not cause direct harm like pests, but they compete for the available resources, which eventually weakens the lily. 
  • Clean up any dead leaves or debris. This is an optimal setting for pests to hide and breed. Keeping the soil clean minimizes that possibility.  
  • Spread a generous layer of mulch on top of the soil. This keeps the plant from getting dehydrated and discourages some snails from approaching.
  • Plant some insect traps in the soil and in the area around the flower beds. This is a great way to limit the insect populations, and in turn, to decrease pathogen transmission. 
  • Keep a healthy distance between the plants. Whether they’re in pots or in flower beds out in the garden, this keeps the pathogens and insects from jumping between plants. 
  • Good ventilation is imperative to plant health. This applies to both the soil and the surroundings. 


Fighting off pests and plant diseases is a normal part of any gardeners’ schedule. Prevention is definitely better than engaging in a battle with tiny wicked bugs. However, sometimes it’s unavoidable.