How to Grow Holy Basil (Tulsi) at Home

Holy basil (tulsi)

Overview

Holy basil, or tulsi, is a mint-family basil. Its leaves taste like a mix of clove, mint, and basil, and they’re often steeped as a tea (NC State Extension). If you already buy boxed tulsi tea, a pot on the patio means fresh leaves to pick and a jar you dried yourself.

In most of the US, you grow it like a tomato: start it warm, plant it out after frost, and pick until the first cold night.

Here’s the short version:

1. Buy Ocimum tenuiflorum. Thai basil is a different plant. See Is Thai basil the same as holy basil?
2. It can’t take frost. Outside zones 10–11, grow it as an annual, or as a potted plant you bring indoors.
3. Start seed indoors about six weeks before planting out. Plant out once nights stay above 50°F.
4. It grows well in a pot. A pot also lets you carry it indoors for winter.
5. Pinch it all summer and harvest the leaves to dry for tea.
6. Drinking it isn’t for everyone. That includes anyone pregnant, breastfeeding, or trying to conceive, anyone with type 2 diabetes or an underactive thyroid, and anyone with surgery coming up. If you take any medicine, ask your doctor or pharmacist first. See Safety notes for the full list.

Holy basil can share a patio with the five easy herbs in our Start Your First Medicinal Herb Garden guide, which covers choosing pots and placing them where you’ll use them. Two of those five, lemon balm and peppermint, are tea herbs too.

Which holy basil to grow

Holy basil, tulsi, and tulasi are names for one plant, Ocimum tenuiflorum. Older labels call it O. sanctum (NC State Extension; Memorial Sloan Kettering).

Leaves come in green or red (Wisconsin Master Gardener). One grower’s guide names three main varieties: Rama, Krishna and Vana (Practical Self Reliance).

Seed catalogs may also use their own names. Johnny’s, for example, sells a ‘Kapoor Tulsi’ with no botanical name on its list page. Check the packet itself before you buy.

Is Thai basil the same as holy basil?

No. Thai basil is a kind of sweet basil, Ocimum basilicum (NC State Extension). The common names overlap, so the botanical name on the packet settles it.

To check a packet, look for “Ocimum tenuiflorum” or “Ocimum sanctum.” “Ocimum basilicum” means sweet basil, Thai basil included.

Where to plant holy basil

Give holy basil full sun, at least six hours a day. It wants soil that drains well but stays evenly moist, and it does poorly in waterlogged ground (NC State Extension). In a bed, space plants 12 to 18 inches apart, and top-dress with an inch of compost in spring and again in midsummer (Practical Self Reliance).

Warmth matters most. Basil in general needs temperatures above 50°F to grow, does best in the 80s and 90s °F, and turns black with frost (Wisconsin Master Gardener). For when to plant out, see When to start holy basil seeds.

Is holy basil an annual or a perennial?

Technically, it’s a short-lived perennial or subshrub (NC State Extension). It survives winter outdoors only in USDA zones 10 and 11 (Practical Self Reliance).

Everywhere else, grow it as an annual. Or keep it in a pot and bring it indoors for winter.

Does holy basil spread?

It can. Holy basil seeds itself wherever summers are warm enough to ripen the seed (Practical Self Reliance). Outside its native range it can turn into an aggressive weed, so a container or a confined spot is the safer choice (NC State Extension).

Pinching off the flower spikes limits seed. See Flowers: pinch or keep?

How to grow holy basil from seed

When to start holy basil seeds

Sow seeds indoors about six weeks before you plan to set plants out (Johnny’s Selected Seeds). Plant out after your last frost, once nights stay above 50°F. For bigger transplants, you can start up to 12 weeks ahead (Practical Self Reliance).

Your local extension office can tell you your average last frost date. Nights can stay cold for a while after that date, so count the six weeks back from when you expect warm nights.

Sowing holy basil seeds indoors

Hands-on time is about 15 minutes for a tray.

1. Fill a seed tray or small pots with damp seed-starting mix.
2. Sow it shallowly: Johnny’s says about ¼ inch deep, and to “sow more shallowly than other basils” (Johnny’s Selected Seeds).
3. Keep the tray warm, around 70°F, and expect seedlings in about five to 10 days (Johnny’s). A heat mat helps in a cool room. Don’t give up early, though. One grower’s guide allows up to three weeks, and basil in general sprouts more slowly when it’s cool (Practical Self Reliance; Wisconsin Master Gardener).
4. Keep the mix moist but not soggy. In basil, damping off, which kills seedlings, happens mostly when the soil is too wet (Wisconsin Master Gardener).
5. Johnny’s says to transplant when seedlings have three or four sets of leaves (Johnny’s). Harden them off first, setting them outside for longer each day over about a week (Practical Self Reliance). Then plant them out at the spacing above, or one to a pot.

Growing holy basil in a pot

Holy basil grows well in a pot. For a plant you’ll keep indoors, choose one 6 to 8 inches across, with drainage holes (Practical Self Reliance). Grow one plant per pot.

Potting mix: holy basil likes moderately rich, consistently moist soil (Johnny’s Selected Seeds). A compost-based mix fits, such as the potting mix recipe in our start-your-garden guide.

Water deeply when the top inch feels dry, then let the pot drain. Yellowing lower leaves usually mean the soil is staying too wet (Practical Self Reliance). Pots dry out fast, and holy basil isn’t drought tolerant (Johnny’s).

Feed: holy basil is a moderate feeder. Indoors, give it a balanced liquid fertilizer every four to six weeks while it’s growing, and less in winter (Practical Self Reliance). For outdoor pots, our advice is to start with the general feeding advice in our start-your-garden guide.

A pot is also what makes winter possible. See Can you grow holy basil indoors in winter?

Pinching and summer care

Pinching holy basil for a bushier plant

Pinching takes a minute or two per plant.

1. Once the plant has several sets of leaves, pinch off the top of each stem just above a pair of leaves. Pinching the tips makes basil branch from that spot (Wisconsin Master Gardener).
2. Repeat every few weeks while the plant is growing (Practical Self Reliance).

Over the summer, the plant should get wider rather than taller. Save the pinched tips for tea. If stems turn woody and stop producing, cut the plant back by a third and feed it, the usual fix for basil (Wisconsin Master Gardener).

Flowers: pinch or keep?

Sources disagree here. The Wisconsin Master Gardener guide says to remove basil’s flower spikes to keep leaves coming until frost. Practical Self Reliance says tulsi “keeps producing flavorful leaves even while flowering.”

A middle path works. Pinch the spikes on the plants you pick from most. If you want seed, let one plant bloom. Cut the spikes before the seed ripens if you don’t want volunteers next year (see Does holy basil spread?).

Pests and problems

Japanese beetles can strip the leaves, so pick them off by hand (NC State Extension). On basil, aphids and spider mites wash off with a strong spray of water, or you can use insecticidal soap. Root rot mostly comes from soil that stays too wet (Wisconsin Master Gardener).

Harvesting and drying holy basil

When to harvest holy basil for tea

Start picking lightly once the plant is established, at about a foot tall (Practical Self Reliance; Johnny’s Selected Seeds). Pick in the early morning, once the leaves are dry. Before you brew what you pick, check the safety notes.

For one big harvest, see the next section. Make a final harvest before the first frost, or bring the pot in.

How to harvest holy basil so it keeps growing

You can pick a little at a time all summer, or make one big cut. Either way, handle the leaves gently, because they bruise easily (Johnny’s).

Everyday picking, all summer

• Rule: pinch stem tips the way you pinch for a bushier plant, taking no more than about a third of the plant at a time (Practical Self Reliance).
• Check: the plant still looks full after you pick.
• Time: a few minutes.

One big cut before it flowers

• Rule: just before the plant starts to flower, cut the whole plant back to about 6 inches above the ground. For this one harvest, you can take more than a third. For basil in general, Johnny’s advises cutting 4 to 6 inches above the ground “to promote a second growth.”
• Check: every stem still has some leaves below the cut, so the plant has something to regrow from.
• Time: about 10 minutes per pot.

How to dry holy basil for tea

Bundling and hanging takes about 10 minutes.

1. Bundle four to six stems together with kitchen twine ad .

2. Hang the bundles upside down in a warm, well-ventilated room (Practical Self Reliance).

   Or spread the leaves on a screen, or use a dehydrator. Our guide to drying herbs gives the settings and typical drying times.

3. Check the leaves. They’re ready when they feel crisp and crumble between your fingers.

4. Strip the leaves from the stems. Store them in a labeled glass jar with a tight lid ad , away from light.

Once it’s dry, brew it with our hot infusion guide. Don’t drink it if you’re pregnant, breastfeeding, or trying to conceive, have type 2 diabetes or an underactive thyroid, or have surgery coming up. Ask your doctor or pharmacist first if you take any medicine, and your pediatrician before giving it to a child (safety notes).

Can you grow holy basil indoors in winter?

Yes, as long as it’s in a pot.

Bring it in before frost. Move the pot inside well before the first frost, when nights drop toward 50°F (Practical Self Reliance).

Give it light. Put the pot in your brightest, sunniest window, as you would any basil (Wisconsin Master Gardener). If the window is dim, a grow light helps. Four to six hours a day of extra LED light is enough for most indoor plants (Practical Self Reliance).

Expect slower growth. Holy basil slows down below 60°F (Practical Self Reliance), so harvest lightly and feed less until spring. Water it the same way as in Growing holy basil in a pot.

Plants and rooted cuttings go back outside in spring, after hardening off, once nights stay above 50°F.

Rooting holy basil cuttings for winter

A few small cuttings take up less window space than a big outdoor plant. Setting them up takes about five minutes.

1. Cut a 4- to 6-inch tip that hasn’t flowered.
2. Strip the lower leaves. Stand the stem in a glass of water with the bottom leaf node under the water.
3. Change the water every two to three days.
4. Roots usually form in two to three weeks (Practical Self Reliance). Pot the cutting up once the roots are about an inch long.

Traditional uses

Holy basil is an aromatic herb used in traditional Indian medicine (Ayurveda), according to Memorial Sloan Kettering. It’s also used in the Hindu religion (NC State Extension), and one of its English names is sacred basil (Wisconsin Master Gardener).

Many health claims are made for it. The MSD Manual says, “Holy basil is not recommended because the claimed health effects have not been confirmed in high-quality studies in people.” This guide covers growing holy basil and drying its leaves for tea. It makes no health claims, and the safety notes below apply to any tea you make from it. The MSD Manual also calls holy basil “probably safe for most people.”

Parts used

The leaves, plus the soft stem tips you pinch off, are what you dry and steep. See When to harvest holy basil for tea for timing.

Common preparations

• Tea/infusion: fresh or dried leaves steeped in hot water. See our guide to hot infusions. Don’t drink it if you’re pregnant, breastfeeding, or trying to conceive, have type 2 diabetes or an underactive thyroid, or have surgery coming up. Ask your doctor or pharmacist first if you take any medicine, and your pediatrician before giving it to a child (safety notes).
• Tincture: dried leaves steeped in alcohol. The method is the same as for any dried leaf herb. See our guide to tinctures. Alcohol can be a dangerous poison for children, so store tinctures out of their sight and reach. Skip it if you avoid alcohol. Same cautions as the tea (safety notes).
• Cooking: holy basil is usually cooked or brewed rather than eaten raw (NC State Extension). Our advice: eating it is taking it by mouth, so the same cautions as the tea apply (safety notes).

Read the safety notes below before you drink or take any holy basil preparation, tea included.

Companion and garden notes

Holy basil is in the mint family, like lemon balm and peppermint. A pot of each makes a small tea corner on a patio. Put holy basil in the sunniest spot. Keep lemon balm and peppermint out of hard afternoon sun, as our start-your-garden guide advises.

Safety notes

These notes are about drinking it or taking it by mouth, including as tea, not growing it.

The US National Center for Complementary and Integrative Health (NCCIH) has no page on holy basil. Memorial Sloan Kettering’s About Herbs page lists side effects, but it doesn’t cover pregnancy, medicines, or children. Unless another source is named, the health cautions below come from the MSD Manual, which a pharmacist reviewed.

Pregnancy, breastfeeding, and trying to conceive: don’t take holy basil by mouth, including as tea. The MSD Manual says it “might not be safe” for women who are pregnant or trying to become pregnant.

In animal studies, large doses made it less likely that a fertilized egg would attach to the uterus. Its safety while breastfeeding hasn’t been studied. The MSD Manual’s recommendations also say pregnant and breastfeeding women should avoid it.

Diabetes and blood-sugar medicines: holy basil may lower blood sugar. With insulin or sulfonylureas, that could cause hypoglycemia (low blood sugar). The MSD Manual says people with type 2 diabetes should avoid taking it.

Blood thinners and surgery: holy basil might slow blood clotting. With aspirin, warfarin, or other blood thinners, that could mean more bruising and bleeding. It could also raise the risk of bleeding during and after surgery, so don’t take it if you have surgery coming up.

Thyroid: holy basil might lower thyroid hormone. People with an underactive thyroid (hypothyroidism) should avoid taking it.

Sedatives: in animal studies, holy basil may increase the effect of certain sedatives.

Medicines: the MSD Manual says people who take certain medicines, including ones that slow blood clotting or lower blood sugar, should talk to their doctor before taking holy basil. Our advice goes further: if you take any medicine, ask your doctor or pharmacist first. Memorial Sloan Kettering also advises telling your care team about any herbs you use.

Side effects: these include nausea or diarrhea. Studies cover use for up to eight weeks, and longer use hasn’t been studied. Memorial Sloan Kettering also lists headache and agitation.

Alcohol: a tincture is made with alcohol. Poison Control says, “Alcohol can be a dangerous poison for children,” and advises storing alcohol-containing products “out of sight and reach.”

Children: neither the MSD Manual nor Memorial Sloan Kettering gives guidance for children, so ask your pediatrician first. Peppermint has some published guidance for children: European peppermint leaf medicines are labeled for ages 4 and up (see the safety notes in our peppermint guide).

Labels (our advice): buy seeds and plants by botanical name. See Is Thai basil the same as holy basil?

Holy basil asks for warmth more than skill. Start it six weeks before your nights warm up, pinch it often, and bring the pot in before the first frost.

Planning the rest of your patio? Start your first medicinal herb garden.

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