A little about the plant, first- the mint is a perennial herb known for its fragrant leaves. It is also a flowering plant and grows tiny pink or purple flowers.
If you are a fan of the mint plant and have attempted at some point to grow it in your home garden, you will know that white spots on the leaves are a frequent and unwelcome visitor.
A prized commodity in several avenues, mint leaves are a sought-after herb in cooking, medicine, and perfumery.
White spots on mint leaves are a typical case of discoloration, brought about by a possible array of reasons. This article deals with the same and tackles the issue of how one can combat them.
What are the causes of white spots on mint leaves?
There are a few different reasons why your mint plant might be displaying white spots or patches.
1. Bug/Pest infestation:
The most common cause behind white spots is a pest infection.
It is no secret that plants are often susceptible to attack by insects. The mint plant indicates a possible attack by exhibiting white discoloration in patches.
The first pointer to help identify an insect infestation is to check the white spots’ pattern.
If the leaves have many small spots in clusters, it is due to insects. Inspect the underside of the leaves in question. The chances are that you will find mites burrowing on the surface.
2. Spider Mites:
Spider mites are small insects. They get their name from the spider owing to the possession of eight legs( excellent for crawling!) and a waxy abdomen that helps them move around with little resistance.
They are known to thrive in the warmer months, actively breeding in high temperature and humidity conditions.
Female mites burrow in the underside of the mint leaves and also drain the leaf of sap.
Other than spots and holes, another common characteristic that leads one to spider mites is the appearance of webs.
Another type of insect that enjoys dining on mint leaves, thrips, lead to silvery patches on the leaves.
Small insects that are yellow or white, thrips lay eggs on the leaves and multiply rapidly. They will drain the leaves of nutrients to bolster their growth while simultaneously depriving the plant of food.
An additional downside? A thrip infestation is known to trigger and promote virus growth.
A helpful note in recognizing thrip infestations is checking to see if the edges of the mint leaves show a metallic appearance( bronze/silver).
4. Fungal infection:
Otherwise known as powdery mildew, mildew materializes in a different way than pest infestations do. Mildew also causes white spots, but in a texture similar to that of sprinkled flour. It is a sign that there is fungus inhabiting the plant.
Mildew is the result of a biotrophic fungus that is known to attack plants. Parasitic by nature, it makes the plant( mint, in this case) its host, sapping the plant of essential nutrients.
The fungus germinates through spores.
Mint leaves are thin and not very difficult to pierce. They lend easy access to attacking fungus, who quickly formed spores and filaments while draining nutrients from the epidermal layer.
Of the other reasons that could potentially cause white spots, some are abiotic. These include an excess of pesticide and manure.
How do you get rid of white spots on mint leaves?
There are several ways to get rid of white spots. However, it is important to accurately diagnose the problem and research its solution before diving into damage control.
1. Trimming/Cutting back the plant
An obvious way in which to repair discoloration and spotting is strategic trimming. It applies to both bug and fungal infestations and has shown good efficacy in deterring further growth.
Please get rid of the damaged leaves and allow your plant adequate recovery time before using them again. The plant will require around 3-4 weeks to grow new leaves again, this time free from the presence of white spots.
“Cleaning” the mint plant is another trick that can help eliminate white spots with considerably quicker results. All you need to do is concoct a solution of soap and water( more water than soap) and apply liberally to both sides of the leaf in question.
The soap and water cleanse the surfaces of infestations. Do not scrub. You are not trying to remove the spots physically; all you are doing is eliminating insects so the plant can recover in its own time.
3. Baking soda
Adding baking soda to the soap-water solution is another great way to clean.
Remember to calibrate well- add a teaspoon of soap and soda to a gallon of water.
Apply, leave on, and rinse. Alternatively, you can use mouthwash. It restricts the growth of spores formed as a result of a fungus.
Mouthwash is a highly concentrated reagent, and you should use it sparingly.
Remember to dilute it before application. Using too much of the compound may alter the leaf chemically, and we certainly do not want that to happen.
4. Bring in a beneficial insect
A creative solution to tackling bug infestations( especially spider mites), this remedial method involves another insect.
If you decide on an insect that will eat the mites and rid your plant of its presence, why not do it?
Of course, it is important first to vet the situation and ensure safety. It will not be an effective method if your choice of remedial insect poses a threat to the plant’s well-being or you.
Can I eat mint leaves with white spots?
To answer briefly, yes. The spots are not dangerous, except when they are indicative of an active infestation.
Yes, you are liable to find the flavor altered, but you are not likely to fall sick due to the consumption of the spotted mint leaves.
It has been controversial, with salient questions on how spots can often result from permanent mildew. That is not the case. If you have cleaned the leaves you are consuming, you are, so to say, safe.
How to find out if a mint leaf is bad or spoiled?
The question of the hour. It is not very difficult to ascertain whether or not a mint leaf is unfit for consumption. The first indication is, of course, a largely altered taste. Do not consume the leaves if you find that the mint leaves do not exhibit any external damage signs but taste bad.
Check for active infestation. Spider mites form webs in and around the plant.
If you notice webs, scrap the leaves. Secondly, inspect the undersides thoroughly. An infestation is not hard to miss as a result of the mites clustering in large numbers.
The last point is to look for a dramatically altered appearance. Diseased plants have certain common characteristics- dry leaves, yellowing edges, withering and drooping.
Can you easily identify white spots on mint leaves?
Yes, you can. A white spot is fairly easy to discern unless it happens to be very faint.
In conclusion, you can get rid of white spots on mint leaves without difficulty. All you need to do is formulate an accurate diagnosis, following which a remedy can be devised.
In my experience, I have found that preventing an outbreak in the early stages of a development that causes white spots returns better results than a cure administered in later stages.
The mint plant is a delicate being. Keep away from direct sunlight and regulate the temperature( especially in the summer months).
Water frequently( do not overwater), and use fresh, organic manure.
A good watering schedule will keep the plant from frying out, which is one of the primary causes of a mildew infection.
Once in a while, take to spraying the leaves with water and neem oil.
Neem is a natural antiseptic and will prevent insects from nesting on/under the leaves. It prevents insect colonies from forming. Remember also to implement strategic planting- space out the plants.
The watchwords are patience and care. Keep this in mind and watch your plants flourish!