Growing Thai Basil: A Taste of Home

If you grew up eating Thai food, you know the smell of Thai basil. It’s the difference between good pho and great pho. It’s what makes pad krapow actually taste like pad krapow. And it’s almost impossible to find fresh at regular grocery stores.

The ones that do carry it charge $4 for a tiny plastic clamshell that wilts by the time you get home. Meanwhile, a single Thai basil plant will give you more leaves than you can use all summer for less than $5.

Growing your own isn’t just economical. It’s having that smell in your backyard whenever you want it.

Why Thai Basil Is Different

Thai basil (also called holy basil or bai horapa) isn’t the same as Italian sweet basil. The flavor is more anise-forward, with a slight licorice kick. The leaves are darker, shinier, and tougher. And unlike sweet basil, Thai basil holds up to high heat without turning bitter or mushy.

You can’t substitute one for the other. If a recipe calls for Thai basil, Italian basil won’t cut it. Trust me, I’ve tried.

Starting from Seed vs. Transplants

Transplants are easier. If you can find Thai basil starts at an Asian grocery store or farmers market, buy them. Plant them. Done.

Seeds take longer but cost less. You can order Thai basil seeds online (look for “Siam Queen” or “Queenette” varieties). Start them indoors 6-8 weeks before your last frost date, or direct sow outdoors after the soil warms up in late spring.

What you need for seeds:

Seed starting mix or potting soil
Small pots or seed trays
A sunny windowsill or grow light
Patience (germination takes 7-14 days)

How to start from seed:

Fill your pots with moist soil.
Sprinkle 2-3 seeds on top and lightly cover with soil (1/4 inch).
Keep the soil consistently moist but not waterlogged.
Place in a warm spot (70-75°F is ideal).
Once seedlings have 2-3 sets of true leaves, transplant to bigger pots or outdoors.

Where to Plant It

Thai basil loves sun and heat. The more, the better.

Best conditions:

Full sun (6-8 hours minimum)
Well-draining soil
Warm temperatures (it sulks in cold weather)
Protection from strong winds

Container or ground? Both work. I grow mine in pots so I can move them if we get a random cold snap. Plus, it’s easier to bring a pot inside when I need fresh leaves for dinner.

If you’re planting in the ground, space them 12 inches apart. They’ll bush out.

Watering and Feeding

Thai basil likes consistent moisture but hates wet feet.

How to water:

Water when the top inch of soil feels dry.
Water deeply so the roots grow strong.
Avoid overhead watering if possible - wet leaves invite fungal issues.
In hot weather, you might need to water daily.

Fertilizer: Thai basil is a heavy feeder. If you want lots of leaves, feed it.

Use a balanced liquid fertilizer (like 10-10-10) every 2-3 weeks.
Or mix compost into the soil at planting time and top-dress with more compost mid-season.
Too much nitrogen makes lots of leaves but weak flavor. Balance is key.

Pinching Back for Bushier Growth

This is the most important thing you can do.

Thai basil wants to grow tall and flower. If you let it, it’ll shoot up, make pretty purple flowers, and then get woody and bitter. You don’t want that.

How to pinch:

Once the plant has 6-8 leaves, pinch off the top set of leaves just above a leaf node.
This forces the plant to branch out instead of growing tall.
Keep pinching the tips every week or two throughout the growing season.
Remove any flower buds as soon as you see them (unless you want seeds).

The more you pinch, the bushier and more productive the plant becomes. I know it feels wrong to “hurt” the plant, but you’re actually helping it.

Harvesting Without Killing the Plant

The rule: Never take more than 1/3 of the plant at once.

How to harvest:

Cut stems just above a leaf node (where leaves meet the stem).
Take from the top and sides, not the bottom.
Harvest in the morning after the dew dries but before the heat of the day.
The more you harvest, the more it grows - it’s like pinching, but with a purpose.

Don’t just pluck individual leaves. Cut whole stems. This encourages branching and keeps the plant compact.

Common Problems

Flowers appearing everywhere: Pinch them off. Once Thai basil flowers, the leaves get bitter and the plant focuses on seed production instead of making more leaves.

Leaves turning yellow: Either overwatering, underwatering, or nutrient deficiency. Check the soil moisture first, then consider feeding it.

Holes in leaves: Probably caterpillars or beetles. Check the undersides of leaves. Hand-pick pests or spray with insecticidal soap.

Plant looks sad and droopy: Too much sun (rare), not enough water (common), or root rot from overwatering (also common). Feel the soil to diagnose.

Leaves taste bland: Not enough sun, too much nitrogen fertilizer, or the plant is stressed. Thai basil needs heat and sun to develop its signature flavor.

What to Do at the End of the Season

Thai basil is technically a perennial in tropical climates, but in most of the US, it’s an annual. It’ll die at the first frost.

Your options:

Let it go. Enjoy it all summer, then compost it in fall and start fresh next year.
Bring it indoors. If you have a sunny window or grow light, pot it up and bring it inside before the first frost. It won’t thrive indoors like it does outside, but you’ll get some leaves through winter.
Save seeds. Let a few flowers go to seed at the end of the season. Collect the seeds and store them in a cool, dry place for next year.
Take cuttings. Thai basil roots easily in water. Snip a few stems, stick them in a jar of water, and you’ll have roots in 1-2 weeks. Plant them and keep them alive indoors until spring.

How We Use It

In our house, Thai basil shows up in:

Pho (essential, non-negotiable)
Pad krapow (Thai basil stir-fry with ground pork or chicken)
Tom yum soup
Green curry
Fresh spring rolls
Anywhere we want that anise-basil flavor

My mom always had Thai basil in the garden when I was growing up. She’d send me out to pick a handful before dinner, and I’d come back with my hands smelling like licorice. Now I do the same thing with my kids, except they complain about bugs.

The smell still brings me back.

Why It’s Worth Growing

Thai basil costs $4 for a few sprigs at the store. A single plant costs $3-5 and produces hundreds of leaves all summer. The math is obvious.

But beyond the money, there’s something satisfying about cooking with herbs you grew yourself. Especially when it’s an herb that connects to your family’s food traditions.

Thai basil isn’t hard to grow. It just wants sun, water, and regular pinching. Give it that, and you’ll have more fresh basil than you know what to do with.

(Kidding. You’ll use all of it.)