Are your purple basil leaves turning green? Is the stem turning brown? Are the leaves covered in white spots?

If you answered yes to any of those questions, we can help!

In this article, you’ll learn the answers to some of the most frequently asked questions about growing basil.

Why are my purple basil leaves turning green?

There are three possibilities that might be turning your basil leaves green.

First, it may just be a genetic issue. According to a study from Purdue University, the gene that causes the purple coloring is unstable.

Two, you may have accidentally chosen a variety that has both green and purple leaves. Use this chart from the University of Hawaii to find the varieties with only purple leaves.

And finally, your basil may not be getting enough light to produce the purple pigment. Try moving it to a sunnier location, increasing its time under a grow light, or adding another light source.

Why are my basil leaves turning light green?

Your basil leaves might be turning light green for two reasons.

First, it might not be getting enough light. Plants need light in order to create chlorophyll, which makes them green.

Second, it might not be getting enough nutrients. Provide more fertilizer or adjust the nutrient solution for stronger growth.

Why are my basil leaves turning yellow?

There are a lot of reasons your basil leaves might be turning yellow.

It’s normal for the smaller, lower leaves to turn yellow and fall off, as they don’t get as much light as the higher leaves.

If the problem is widespread, it might be more serious.

For example, too much water can cause root rot, which is one of the most common causes of yellow basil leaves.

Clean off any dead roots and transplant it to another dry and clean spot. Also, water your basil only when the soil is dry. It’s better to wait too long between watering than to water too often.

If you’re growing in a hydroponic system, introduce dry periods or put more oxygen in your nutrient solution.

If the yellowing comes in the form of spots, it might be an infection called downy mildew.

Downy mildew usually spreads in colder wet weather. If you catch it early enough, you can prevent it from spreading by cutting off infected leaves.

Why are my basil leaves turning green? Close up of basil plants growing in hydroponic system.

Why does my basil have small white spots?

White spots on basil is never a good sign.

If the spots move when you try to touch them, then you have a whitefly infestation. Whiteflies also cause black sooty mold and the leaves to turn yellow and dry.

Try to brush, vacuum or wash off as many insects as you can. Cut off any severely infected leaves and continue to monitor your plant for signs of the insects for a few months.

If the spots don’t move, it’s probably powdery mildew. It looks like powdery white or gray splotches on leaves and usually starts on the underside of the leaves.

Luckily, it isn’t usually fatal to basil plants. But it will weaken and stress your plant, making it vulnerable to other conditions. Cut off infected leaves and treat the plant with a fungicide.

Why is the main stem of my basil turning brown?

If the main stem of your basil is turning brown, don’t worry!

Basil is a woody plant, so old stems will turn brown and hard. Only new growth will stay green.

However, if your basil’s stem is turning brown and mushy, or slimy, it probably has a fungal infection. Look for other signs of infection like slow growth, yellowing or decaying leaves.

This type of fungal infection usually enters basil through the roots, so check the roots for signs of infection too. If they’re also brown and mushy, your plant has a fungal infection.

Unfortunately, once the stem is infected, the plant can’t be saved.

Why is my basil flowering so much?

Basil plants are naturally annuals. This means that each year they’ll sprout flowers in order to create seeds, and then they’ll die.

If you want to let your basil live out it’s natural life cycle, feel free to let the flowers bloom.

Otherwise, keep your basil alive indefinitely by clipping off flower buds as soon as possible!

You can also harvest half your basil plant by cutting it down, in order to promote new leaf-growth and move away from the flowering stage.

If you’re having trouble keeping your basil alive, read our blog, “Foolproof Advice for Keeping Your Basil Healthy,” for more tips!

If you’re still struggling, our Pure Greens Container Farms allow basil to be grown in perfect conditions all-year round with little risk of pests and diseases.

Visit our website or call us at 602-753-3469 for more information.