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Is Thai Basil a Perennial? (Let’s Find Out)

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Last updated on September 23rd, 2022 at 04:16 pm

Most varieties of the basil plant are annual, i.e., they round up their lifespan in one year. Therefore, a basil plant will continue to produce fresh green leaves as long as it encounters favorable conditions.

While it is possible to have a year-round supply of Thai basil, some folks might be moved to ask if it is possible to extend the typical one-year lifespan of Thai basil.

Is Thai basil a perennial? Thai basil is a short-lived perennial that can last for close to three years. However, Thai basil’s flavor fades over time, so it is advisable to replace the plant every year to have a steady supply of favorable leaves.

What Season is Best for Thai Basil?

Basil is a frost-sensitive plant. Therefore, the best season to start growing your Thai basil is during summer or dry season, as the case may be.

Being frost-sensitive, cold, or frosty weather can lead to stunted growth or even the death of the plant.

However, Thai basil thrives outdoors as they love to bask in full sun and take advantage of the warmth to produce massive yield.

You should give indoor Thai basil plenty of sunlight to boost its growth and improve the flavor of the leaves.

It would be epic to plant Thai basil during the dry season as it tends to hold up better in hot climates than during cold or frosty weather.

How to Care for Thai Basil

Growing Thai basil is just as easy as growing any other variety of basil.

In addition, Thai basil does not require much stress. All you need to do is provide the plant with its basic requirements.

What are the basic needs of a Thai basil plant?

1. Sunlight:

Thai basil is a sunlover. It loves to bask in the warmth of sunlight. Provide your plant with six hours of daylight daily and watch it bloom.

Pick the sunniest portion of your garden for your Thai basil.

You should place indoor Thai basil near a south or west-facing window or in any spot where it can access direct sunlight.

Thai basil performs excellently when planted in regions with hot climates.

2. Soil:

When planting Thai basil, choose soil rich in organic matter, slightly acidic, and well-draining; Thai basil loves somewhat moist soil, so waterlogged soil would be a poor choice.

It is advisable to top up the soil fertility with additional organic fertilizer. This would go a long way in improving soil fertility and boosting the plant’s growth and yield.

3. Watering:

Thai basil does not require a lot of watering. It requires only a small quantity of soil moisture so that you can water it at least once a week with approximately one inch of water.

It will help if you put off watering till the top layer of the soil becomes dry. Water only the root of the plant and leave the leaves out of it.

It would be best if you were cautious of the amount of water you feed Thai basil with. Over-watering can cause the leaves to turn yellow till they eventually fall off.

On the other hand, under-watering leads to dehydration of the plant, and the leaves begin to appear stressed and malnourished.

4. Harvesting:

Thai loves constant picking and plucking. You should do a regular check on your Thai basil to pinch off new flowers.

Flowers on your Thai basil are a sign that your Thai plant is about to start producing seeds. A Thai basil plant will die after producing seeds.

So, pinch off the flowers so that the plants keep growing more and more fresh leaves. The leaves should as well be harvested regularly to provide room for new ones.

5. Fertilizer application:

This would not be necessary if you had added organic matter to the soil in its early stage. The addition of organic compost does a lot in improving soil fertility.

Constant fertilization is not necessary. A single dose of organic compost can last in the soil for months.

6. Mulching:

Mulching is done to prevent loss of soil moisture. It also helps to curtail the growth of weeds. For example, you could use dried straw or hay to mulch your Thai basil plant.

What Season is Worse for Growing Thai Basil?

Thai basil, as stated earlier, is a frost-sensitive plant. Therefore, it would be unwise to begin growing Thai basil during winter.

A Thai plant dreads the advancement of the winter months because a temperature dip as low as 30-degrees-Fahrenheit is enough to kill it.

Cold and frosty weather is detrimental to your plant. A Thai basil plant is grown outdoors rarely makes it past winter. Grow Thai basil indoors during weather so they can get some warmth.

Potted Thai basil can be placed outside during the day and brought inside at night.

What to do When Thai Basil is Dying.

Basil plants are quick to display symptoms when they encounter stress.

So if your Thai basil begins to show signs such as drooping and wilting leaves, yellowish leaves, spots on leaves, etc., then it is under duress and needs saving.

The most common factors that can put a Thai plant in distress are: over/under watering, too much/insufficient sunlight, and pest/disease.

Now, how can you save Thai basil?

  • If over-watering seems to be the case, then cut down the rate you water the plant and give the soil more time to dry out. Or, better still, transplant to drier ground.

It’s pretty easy to fix under watering in a Thai basil plant.

Simply give it thorough watering and place it under shade for some time till it springs back to life. Also, pinch off the wilted or crisply leaves that were affected.

  • Basil prefers full sun. Therefore, give it six hours of sunlight in a day—nothing more, nothing less.
  • If your plant has been affected by diseases such as fusarium wilt or root rot, endeavor to remove all the affected parts and repot the plant.


A Thai basil plant is susceptible to frost and can hardly make it past one winter season. However, you can have a year-round supply of Thai basil by planting it indoors during winter.

Growing Thai basil is pretty easy; once it gets its basic needs, it doesn’t require much more effort to thrive and bloom for months.


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