Browning Basil
The more you learn about basil, the more you start to understand that it is actually a pretty high maintenance plant. But that doesn’t mean that it’s fragile! As long as you can maintain the ideal growing conditions of a basil plant, it will reward you with gorgeous tasting and smelling foliage.
Whether you are growing your basil plants indoors or outdoors, that are certain things that can happen that will cause the leaves of the plant to brown. This can a be a tricky issue to deal with as a gardener, because there are so many reasons why a basil plant may have be turning brown.
This article is going to go through every option as to why a basil plant may be turning brown, as well as how you can deal with it! So get a paper and a pen, and get ready to become equipped with knowledge!
Curious about growing basil indoors? Click here!
Want to know why your basil is dying? Click here!
What is basil bolting? Learn all about it here!
When is the right time to harvest basil? The answer is here!
Find out the best methods for controlling basil pests here!
Why is are my Basil Leaves Turning Brown?
Something kind of hilarious about basil plants is the fact that they suffer from so many issues, and so many of the symptoms are the same! As a gardener, you will have to do a little bit of digging to figure out what is bugging your basil and causing basil leaves turning brown. A brown spot on a basil leaf could mean a fungal disease infected basil plant, or it could be a dehydrated plant.
Here are 7 reasons why you are experiencing basil browning:
1. Overwatering
The most common issues that gardeners will face often come from watering issues. Basil is very particular when it comes to the amount of water that it receives, and over watering is the more detrimental of the two.
Not only will your plant start having yellowing leaves or browning leaves, it will also start to develop root rot. Hopefully you’ll be able to discover the issue before it leads to this, because there is not much that can be done once a plant develops root rot.
How to fix it: if you’ve discovered the issue before root rot has set in, that’s great news! All you have to do from here is replant your basil in a pot with a ton of drainage holes and in soil that is also well draining.
Growing basil indoors will often experience over watering more often because evaporation doesn’t happen as quickly. Frequently check your roots and don’t water your plant if the soil is still moist, if it has moist soil, just wait a few days before you water again.
2. Under watering
Under watering is the far more manageable issue when it comes to browning basil. All you really have to do is water basil properly for it to be happy again, and trim away the leaves that are browning.
Your plant will suffer if it is left out to dry for extended periods of time, and a basil leaf will tell you by yellowing, browning, shrinking, or curling. This is especially common if the basil plant is in an area that receives a ton of sunlight.
How to fix it: proper placement. A gardener isn’t always going to know the absolute perfect place for a plant. Sometimes trial and error is the only way. But the best way to avoid under watering is by obtaining proper sun exposure.
If you live in an area with more mild temperatures, your basil plant will be happy with direct sunlight for the majority of the day (4-6 hours). If you live in an area that is very hot, your plant should be placed in an area with partial shade to avoid leaf scorch.
Growing basil indoors is a little bit easier to maintain because they’re usually happy in a south facing window. If this is too much, basil leaf browning is usually caused by the plant be placed too close to the window.
Another tip is to simply put yourself under a strict watering schedule. It is always better to under water than to over water, but just do your due diligence and regularly check to soil to check the moisture level.
3. Temperature Stress
One of the most sensitive aspects of caring for basil is achieving the correct temperature. Basil plants really do not appreciate temperature stress, whether that be temperatures that are too low or temperatures that are too high.
Leaves browning can very commonly be caused by a plant that has been exposed to unexpectedly hot or cold temperatures, or even by a draft that is different from the mean temperature.
The damage is made apparent quite quickly, as leaves will curl and change color. New leaves can be deformed and very small, or it can stunt the growth of the plant entirely.
How to fix it: luckily, this is also one of the easiest issues to avoid. Don’t place your basil in an area that is particularly drafty, too close to the window, or by a window that doesn’t have good insulation.
If growing basil outdoors, make sure you don’t plant your basil seedlings in the earth before the last threat of frost, as seedlings are extremely sensitive to cold and they may perish. The same rule applies to exposing basil seedlings to too much heat or sunlight.
4. Insufficient Light
Striking the balance between adequate sunlight and appropriate temperature can be rather tricky to achieve when it comes to basil plants. Though they don’t want to be too warm, they also don’t want to be deprived of sunshine.
A basil plant will tell you it’s not receiving enough sun exposure by yellowing or browning leaves that start to curl up. Luckily, the issue isn’t so dire that the plant can’t be saved.
How to fix it: you just have to move your plant! If growing outdoors, you’ll have to transplant your herbs to an area that receives more sunlight or less sunlight. You’ll be able to tell based off of the situation of your property.
If growing basil indoors, your basil plant should be placed in a south facing window. If you do not have such a window, you may have to purchase a grow light to achieve the right level of sun exposure. Just remember: young basil seedlings don’t need as much sun as mature plants do.
5. Root Bound
Another reason for your basil plant changing color could be because it is root bound! Basil plants have impressive and extensive root systems that need a ton of space to grow!
Basil roots grow pretty deep into the soil – about as deep as the plant is tall – and if it is planted in a container or pot that is too small, roots will start to grow out of the drainage holes.
How to fix it: find the right pot. Like we mentioned, basil roots are as deep as the plant is tall, so your pot will likely be tall and narrow. Basil will be perfectly happy in this type of container, preferably with several drainage holes instead of one single drainage hole.
6. Pests
As much as humans love basil leaves, so do pests. They are particularly popular amongst sap-sucking pests, like aphids, spider mites, thrips, and scales.
These types of pests attach themselves – usually on the under side – of basil leaves on the vein of the plant. From here, they well suck out the moisture and nutrients the plant needs, effectively browning basil leaves or causing leaf spot. Try to catch this before they cover the entire plant!
How to fix it: the best way to avoid pests is by being diligent. Always check your basil leaves – upper side and under side – for these pesky little pests. You can also use insecticidal soap to get rid of them and keep them away.
If you’re worried about pests, you can always grow basil indoors as well. If you grow basil indoors those common pests won’t be able to access them. This is why if you’re bringing a plant inside, make sure there are no pests on it so that they can’t transfer to your other house plants.
7. Disease
Disease is another very common issue that outdoor basil plants will face. Fusarium wilt is very common with basil, as well as basil downy mildew, also known as bacterial leaf spot.
Fusarium wilt is a disease that starts in the soil, and unfortunately there is no way to save your plant once this issue develops. All you can do is dispose of the infected plant in an area where other plant life can’t be infected. You’ll be able to tell your plant has this fungal infection because its roots will be mushy and rotting and leaves may have black spots.
The basil downy mildew pathogen occurs in conditions that are very warm and humid. This is why watering basil from underneath is important, and watering on days where it is sunny enough for the water to evaporate properly, so that the basil leaves don’t stay wet and become susceptible. You’ll be able to tell it has downy mildew because of tiny black or brown spots all over the infected leaves.
What’s the Best Way to Protect Basil from Browning?
The take away from this is that the absolutely best protection from basil browning is by maintaining a healthy plant. Achieving the ideal growing conditions are simple enough if you know what you’re doing.
It can be tricky to get the hang of it, but eventually once you do, your herb garden will be rewarding you with a constant supply of fresh basil – so much that you won’t know what to do with it all!
FAQs
What is the most popular basil variety?
Sweet basil, purple basil, lemon basil, and Genovese basil are some very popular basil varieties. Sweet basil is the most commonly grown type of basil because of its lovely flavor and bushy fresh basil leaves.
Purple basil is known for its incredible fragrance and gorgeous purple color, whereas Genovese basil is the perfect herb for you if you’re looking for a tasty, fresh, and beautiful garnish. Lemon basil is used a ton in eastern Asian cuisines for its lemony kick and intense fragrance.
What are some ways to use fresh basil leaves?
A great way to use fresh basil is by making pesto! It’s completely delicious, you can make heaps of it, and it keeps for a very long time in the fridge even after it has been opened because olive oil is a natural preservative.
Dried basil is also a super common herb to have in the pantry. Though it has less of a flavorful and aromatic quality to it, it provides a wonderful kick to soups, stews, and pasta dishes.
What is a fungal disease that basil commonly gets?
Disease is another very common issue that outdoor basil plants will face. Fusarium wilt is very common with basil, as well as basil downy mildew, also known as bacterial leaf spot.
Fusarium wilt is a disease that starts in the soil, and unfortunately there is no way to save your plant once this issue develops. All you can do is dispose of the infected plant in an area where other plant life can’t be infected. You’ll be able to tell your plant has this fungal infection because its roots will be mushy and rotting and leaves may have black spots.
The downy mildew pathogen occurs in conditions that are very warm and humid. This is why watering basil from underneath is important, and watering on days where it is sunny enough for the water to evaporate properly, so that the basil leaves don’t stay wet and become susceptible. You’ll be able to tell it has downy mildew because of tiny black or brown spots all over the infected leaves.
Where is the best place to plant basil in the garden?
The best place to plant basil in the garden is in an area that receives morning sun but partial shade in the heat of the afternoon, in an area that is protected from strong winds, and in soil that has been amended with compost and has excellent drainage.
Is it possible to start a basil seed indoors?
It’s actually a great method to start a basil seed indoors rather than outdoors, because you can better control their growing conditions indoors. A basil seed needs specific temperatures, moist soil, and tons of nutrients to grow into a healthy, mature plant.