Last updated on January 10th, 2022
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If you notice that your Lavatera shrub is discolouring or wilting, there is a high chance that they are suffering from disease or pest issues, the good news is that it is nearly always treatable. It is crucial to identify the culprit according to the symptoms displayed to employ a suitable treatment method. This is usually as simple as applying a pesticide for pests and fungicide for fungus infections such as Hollyhock rust and mildew.
In the sections below, are various pests and diseases that I have noticed can become a problem for Lavatera. Go through the different symptoms and narrow down the most likely suspect. Shall we begin?
Diseases that attack Lavatera
First on the list is Hollyhock Rust that causes the leaves to discolour and form a rugged appearance. The disease, which is the fungus Puccinia malvacearum, is not too serious but it will destroy the plant’s appearance. This fungal disease needs intervention before causing massive defoliation that will weaken the plant.
You will find this infection often affects the mallow family and this is why it is called Hollyhock Rust. Being part of the mallow family, it is found commonly on Lavatera plants too.
The good news is that with proper management, the plants should be able to recover with time. The fungus is dormant in hot weather, but during spring and autumn the fungus produces millions of spores that spread around quickly due to the wind.
It is not easy to avoid these fungi because it is common in most gardens, but you can help the plant recover. Remove the infected leaves and stems and dispose of them or burn them. Don’t put them in your compost bin though.
Get rid of the affected leaves that emerge in the spring and spray the plant with a recommended fungicide that is labelled for use on rust, you will find this on most fungicide sprays. Repeat the application as per the instructions provided to avoid oversaturating the vulnerable plants with chemicals.
Leaf spot disease
Leaf spot is a common bacterial infection that affects various plants worldwide. The disease can come from any of the 120 types of bacteria discovered or fungi and it usually manifests symptoms on the leaf’s surface. The leaves develop brown or black lesions and random spots with yellow margins. The random spots eventually turn black and continue spreading until the leaves die off.
This disease weakens Lavatera because it attacks the leaves that are essential for photosynthesis. To help the plant recover, remove the infected sections and spray an ideal fungicide. Prune the plant at least yearly to improve ventilation and keep recurrent fungal infections at bay.
Another common disease that may affect your Lavatera is powdery mildew and this manifests as white velvety patches on the foliage. It is a microscopic fungus that thrives in warm and humid environments and if left unchecked, it spreads; thus, weakening the plant. The treatment of powdery mildew includes the disposal of the infected sections and the use of fungicides.
As a preventative measure, plant your Lavatera in a sunny spot to keep any available spores dormant and keep the plants well ventilated. I recommend spraying with a fungicide at the first signs of mildew and remove affected leaves.
Phytophthora capsici is responsible for Phytophthora blight that can cause irreparable damage if left unchecked. The pathogen thrives in high humidity areas and that is why it attacks plants in waterlogged soils. It infiltrates the plants from the roots before spreading to the stems and leaves.
It is challenging to save plants attacked by phytophthora blight because, by the time you begin to notice affected leaves, the roots are probably severely damaged. This disease is devastating to plants and there is no chemical intervention to mitigate the problem. Fungicides will only be helpful as a preventative measure to avoid the disease from taking hold. Remove the infected plants and dispose of them in the bin to avoid infecting the other plants.
Read next: Why are my Lavatera leaves turning yellow?
Read next: Why are the leaves in my Lavatera wilting?
Common pests attacking your Lavatera
Aphids such as greenfly, whitefly and blackfly
Small but mighty, aphids — especially in large numbers damage plants. These small insects puncture the leaf surface and feed on the plant sap. In large populations, these insects will leave the plant weak, with spotted, discoloured leaves. They not only feed on the plant’s sap, but they attract other insects such as ants through the honeydew they produce.
The honeydew is also responsible for encouraging sooty mould which is another fungus that further weakens the plant. Manage aphid populations using pesticides, insecticidal soap or organic methods such as neem spray and this also helps stop ants and sooty mould.
Spider mites are not overly dangerous but just like the aphids; they cause damage in large populations. These soft-bodied insects live on the foliage and are so small you need a magnifying glass to spot them. You may spot small webs on the stems and this is a sure indication that they are present.
To prevent the spider mites from depriving your plants of vital plant juices, you need to find suitable control methods. Some prefer using horticultural oil but I personally use a general pesticide as most will kill spider mites effectively.
Along with spider mites and aphids, thrips get nourishment by puncturing plant tissue and feeding on the sap. These slender insects can be translucent, black, dark brown or yellowish in colour, and they have a short lifespan of about two or three weeks so they can disappear as quickly as they come but not before causing significant damage.
You can easily deal with these pests by introducing natural predators such as ladybirds. Amazingly you can actually order these from Amazon or by using pesticides.
You can also use a neem oil spray. Horticultural soap has proven effective in managing large populations without exposing the plants to excessive chemicals.
Slugs and snails
While snails and slugs do not do any systematic damage to Lavatera, they do cosmetic damage. Your plant’s leaves will be left with several holes and slime trails. This is not aesthetically appealing, so you need to control the situation before it escalates.
Deter snails and slugs from attacking the plants by setting up a trap with beer or erecting a physical barrier using mesh fabric, you can also get copper tape for putting around pots that has proven effective.
Alternatively, you can place course material at the base of the plant like eggshells or coarse stones to hinder their movement. Finally, you have always got good old fashioned slug pellets, however, I don’t recommend using these if you can get away with it because they aren’t good for the local wildlife.
Creating holes in your leaves and consuming plant sap, leaf beetles can leave behind considerable damage. They leave behind holes and yellowing foliage that make the plant look miserable. Organise a method of treatment either by introducing natural predators, insecticides or organic methods like using a soapy water spray. Now that you are aware of some of the pests and diseases that attack Lavatera, you are in a better position to nurse them back to health. Pest and disease attacks are not easy to avoid but try to get the issue sorted before things become worse.