How to Grow Tulsi (Indoors or Outside)

Few houseplants can match Tulsi for both beauty and fragrance.  Tulsi, also known as holy basil or sacred basil, is a perennial in tropical and subtropical regions, but it can be grown indoors year round regardless of your climate.

Each year we plant a large patch in our vegetable garden and harvest well before harvest first frost to dry for winter teas.  Unlike other annual basils which bloom and then become bitter, tulsi is known to bloom and keep blooming, providing forage for the bees and fragrance for your garden.

If brought indoors for the winter, tulsi will keep right on blooming and liven up any room with its sweet fragrance.

Growing Tulsi From Seed

Tulsi seeds should be started indoors 6 to 12 weeks before the last frost.  Since tulsi is a tropical plant, it requires warm temperatures to germinate and should be kept in a place that’s at least 70 degrees.  If your house is particularly cool, consider using a seedling heat mat to warm soil temperatures.

The soil should be kept continuously moist, but not soggy.  Seeds will germinate about 3 weeks after planting.

The plants are very frost sensitive, and should not be moved outdoors until several weeks after the last frost date.  Even then, remember to give them an acclimation period to harden off by bringing them indoors into a sheltered place at night for a week or so before permanently planting outdoors.  Cold frames are also a good option.

If you’re growing tulsi indoors, be sure that the plant has ample sunlight in a south-facing window for at least 4-6 hours of direct sunlight per day.

Growing Tulsi From Cuttings

Tulsi also readily grows from cuttings.  Use a pair of sharp garden shears and cut a tulsi stem from an established plant.  Remove all the flowers and most the leaves.  Place the cutting in a glass of water on a sunny windowsill.  Make sure it’s kept continually warm, and change the water every few days to avoid mold or stagnation.  The cutting should take root in a few weeks.

Tulsi Plant Care

Once your tulsi plant is established, it needs continuously warm temperatures to thrive. Tulsi is hardy in zones 10 and 11, and can be grown year-round in the very hottest parts of the US that never see a frost.  For the rest of us, tulsi can be grown as an annual outdoors, or as a perennial houseplant.

Hardiness – Tulsi is hardy to zone 10, and cannot handle any frost.  Ideally, temperatures would remain above 50 degrees for optimal growth.

Sunlight – In ideal conditions, tulsi requires at least 6 hours of sunlight per day.  It can survive part sunlight conditions, with as little as 4 hours of direct sunlight per day.

Soil – Most balanced potting mixes are appropriate for growing indoors.

Fertilizer – Tulsi requires fertile soils to thrive, especially if you’re regularly harvesting leaves for tea and seasoning.  Be sure to supplement with compost to ensure adequate fertility.  To the soil with an inch of rich compost every 6 months.  The best fertilizer for tulsi plants is a balanced 10-10-10 liquid fertilizer and can be applied every few months for indoor plants.

When to Harvest Tulsi

How long does it take to grow tulsi?  Since tulsi is a perennial, it’s best to continuously harvest small amounts of the herb to allow for continued growth.

You can begin to harvest tulsi once the plant reaches about a foot in height.  Pinch back the growing tips to help encourage a bushy plant habit, which will increase yields.  Tulsi plants should be ready for harvest about 40 days after germination and do best with sparse periodic harvests.  If harvested gently, by single leaves or branches, a tulsi plant can continue to produce for several years.

In India, tulsi bushes can reach 4 to 5 feet tall in the intense summer heat, but indoors or in more temperate climates, they stay small and bushy, growing no bigger than 1 to 2 feet.

Types of Holy Basil Plants

There are a surprising number of holy basil varieties, each with their own distinctive characteristics.  Since tulsi has been grown in India for medicine for thousands of years, there has been plenty of time for unique cultivars to develop.  The three main varieties include:

Rama Tulsi

This variety has light green leaves and purple flowers and smells strongly of cloves.  The flavor of this variety is mellower than others, but even though it has stronger smelling leaves.  The mild flavor makes it versatile as an after meal tea, and it’s used to promote healthy digestion.  Rama tulsi is also known as green leaf tulsi.

Krishna Tulsi

A purple leafed variety, krishna tulsi a rarer variety of holy basil.  It grows more slowly, and it’s thought that the slow growth contributes to the accumulation of stronger, spicier and more pungent flavors.  The flavor is peppery and clove like, and the warm spicy tea it produces is used to treat respiratory infections among other things.  Krishna tulsi is also known as Shyama tulsi and purple leaf tulsi.

Vana Tulsi

Considered the best tasting, Vana tulsi is actually a bit harder to find.  The leaves come in two tones, with the upper leaves light green and the lower leaves on the plant coming in darker green.  The flavor is more lemony, unlike the peppery and clove flavored other varieties.

How to Use Tulsi

The most common way to use tulsi is in a tea.  The tea has a natural sweet flavor that reminds me of lemon balm with a slight hint of clove.  A brand called Organic India sells a number of tulsi tea blends, each mixed to bring out different medicinal qualities of the tulsi plant.

Make tulsi tea by steeping about a tablespoon of the herb in 1 cup of near boiling water for 15 minutes.  Bring the water to a boil and then allow it to cool for a few seconds before pouring over the tulsi tea leaves.  Boiling water will drive off the volatile compounds and you won’t get as much flavor in your final tea.  Strain the tea and enjoy plain or with a sweetener.  Honey works particularly well if you’re taking tulsi for respiratory issues.

Beyond tea, tulsi is traditionally used as a spice and it’s sprinkled on foods to enhance the flavor in much the same way that pepper or Italian basil is used.