Ocimum, Lemon Basil, Ornamental Basil, Thai Basil 'Siam Queen'

Ocimum x citriodorum

Family: Lamiaceae (lay-mee-AY-see-ee) (Info)
Genus: Ocimum (OSS-ih-mum) (Info)
Species: x citriodorum (sit-ree-oh-DOR-um) (Info)
Cultivar: Siam Queen
Additional cultivar information:(aka Thai Siam Queen)
Synonym:Ocimum basilicum
Synonym:Ocimum basilicum var. citriodorum




Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun


Grown for foliage


Foliage Color:

Unknown - Tell us


18-24 in. (45-60 cm)

24-36 in. (60-90 cm)


6-9 in. (15-22 cm)


Not Applicable

Where to Grow:

Unknown - Tell us


Unknown - Tell us

Bloom Color:



Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Summer

Late Summer/Early Fall

Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

From herbaceous stem cuttings

From seed; sow indoors before last frost

From seed; direct sow after last frost

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds


This plant is said to grow outdoors in the following regions:

Gaylesville, Alabama

Snowflake, Arizona

Los Angeles, California

Menifee, California

Merced, California

Palm Springs, California

San Jose, California

Delta, Colorado

Brandon, Florida

Largo, Florida

Palm Bay, Florida

Saint Augustine, Florida

Saint Petersburg, Florida

Trenton, Florida

Winthrop Harbor, Illinois

Kenner, Louisiana

Marrero, Louisiana

Bellaire, Michigan

Grand Rapids, Michigan

Saint Louis, Missouri

Los Alamos, New Mexico

Ancram, New York

Brooklyn, New York

Buffalo, New York

Polkton, North Carolina

Columbus, Ohio

Vinton, Ohio

Austin, Texas

Deer Park, Texas

Fort Worth, Texas

Hallettsville, Texas

Iowa Park, Texas

Roanoke, Texas

Round Rock, Texas

Logan, Utah

Leesburg, Virginia

Reston, Virginia

Virginia Beach, Virginia

Glasgow, West Virginia

show all

Gardeners' Notes:


On Nov 10, 2012, ansonfan from Polkton, NC (Zone 7b) wrote:

Thai Basil overwinters easily in a small greenhouse or even on a sunny windowsill. It is ornamental enough to use as a houseplant as long as it gets enough light, and then you can enjoy its aroma all winter. Its spicy flavor can be used in many dishes that benefit from a lemony, peppery flavor such as fish. The blooms are also very long lasting.


On Jul 15, 2007, pajaritomt from Los Alamos, NM (Zone 5a) wrote:

One of my favorite garden plants. It is beautiful with its purple flowers and it is delicious in various Thai dishes that I like to cook. To purchase it I would have to drive 100 miles so, I grow my own in the summer. Sometimes I have even been able to overwinter it indoors.
The Thai people eat the flowers and leaves both and frequently add 1/2 cup to 1 cup of them to various of their dishes that would serve 4 people in the US.
I have not found it necessary to cut off the flowers to keep the plant growing all summer as in Italian basil. I enjoy the blooms both as ornamentals and in cooking.
Siam Queen is the easiest variety to grow that I have found though there are many others.
Not to be confused with Holy or hot basil.


On Jun 4, 2006, Rapunzel_56 from Ancram, NY (Zone 5b) wrote:

I love Thai Basil, but have a hard time finding the plants locally. Next year I'll be growing my own! I use Thai Basil in a flavored oil recipe I use, not only for the lovely flavor, but because it looks so nice and holds up so well. In a gallon of canola oil I put several cayenne peppers, whole pepper -corns, garlic, thai basil and whatever else I've grown in the garden that year! If anyone wants the whole recipe, I would be happy to share! The oil has a wonderful flavor and aroma, and makes a nice gift too.


On May 9, 2006, kimchifan from Los Angeles, CA (Zone 9a) wrote:

Usually the time for me to grow herbs in my desert garden is winter, but this herb prefers instead the summer time. Whereas the seeds did sprout during the winter, they remained small seedlings for months until the weather warmed and summer came around. This is when the plant really began to grow and become mature.

Before I began growing Thai basil myself, I would purchase it during rare trips to an Asian grocer and freeze it in a plastic bag. This would allow me to add that 'missing taste' to my Thai cooking when it was impossible for me to have fresh Thai basil. Granted the dish does not look as beautiful this way, but the taste of the basil is preserved despite the freezing process.


On Sep 1, 2005, critterologist from Frederick, MD (Zone 6b) wrote:

Thai basil is one of my favorite edible ornamentals! The huge flower heads are decorative for weeks. Letting the plant flower only seems to affect the flavor of the flowering branches; new growth still seems fine for harvesting. Leaves are fabulous Thai curries]... I mince fresh leaves together with Thai chiles, ginger, garlic, and a little vegetable oil, then freeze in ice cube trays to add to winter stir fries.


On Nov 4, 2003, ocimum_nate from American Fork, UT (Zone 5a) wrote:

Of the basils I have grown this one has done really well. It is easy to grow. Flowers are attractive but if you want to use this plant for culinary purposes do not let it go to flower. You can do this by pinching it back regularly. I enjoy this basil in stir fries and soups.


On Oct 9, 2003, gardenermaid from Bellaire, MI (Zone 5a) wrote:

I love this basil. It is wonderful, picked fresh and added to your salad or put in anything you would add basil to. It has kind of a licorice smell to it.