Siam Queen Thai Basil


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Enjoy a taste of Thailand in your own garden with Siam Queen Thai Basil! This 1997 AAS Winner is prized for a its extra-large leaves, dark purple flowers, purple stems, and strong, clove-like scent. This popular basil is used throughout Thailand and Southeast Asia, where it is known as Thai Basil and is associated with good luck. It is often used to make traditional Thai dishes such as Pad Krapow and Thai curries. Siam Queen Basil plants can grow up to 3 feet and are withstand hot, tropical climates. They can be grown in containers indoors or directly sown outdoors for a lush, aromatic display and touch of Thai charm in your home.

Also Known As:  Horapha, Bai Horapha, Sweet Basil, Asian Basil, Bai Krapao, Bai Gaprao,  Holy Basil, Lemon Basil, Spicy Basil, Bai Pad Horapha.

We ship in 1 business day. Shipped with USPS First Class Mail.

Plant Name:
Basil, Siam Queen
Latin Name:
Ocimum basilicum
Days to Germinate: 7-14
Days to Harvest: 80
Germination Rate: 80%
Test Date: 10/23
Growth Habit: Bush
USDA Zones: 3-12
Lifespan: Annual, Perennial in Zones 10-12
Brand: TomorrowSeeds
Sunlight: Full Sun, Partial Shade
Heirloom, Open-Pollinated
Fungicide-Treated Seeds:*
Seeds Packed For*: 2024

*Fungicide-treated seeds protect the seedlings from diseases until they are up and growing. Do not eat treated seeds.
**Seeds are freshly packed for the growing season of the year listed. Seeds are still viable beyond pack date. Store in a cool and dry location such as the refrigerator or basement to best preserve germination rates.

Planting Instructions:


Soil Preparation:

Remove weeds, large rocks, and litter from the planting area. Till the soil 8-10 inches deep and rake several times to break up large clods. It is best to do this when the soil is dry enough to not stick to garden tools. Loosening the soil will help the plant establish strong roots.


Optionally, start indoors in containers 4-6 weeks before last frost. Keep seedlings >70F. Harden off then transplant to, or sow, in fertile, moist, well-draining soil in full sun after all frost passes in Spring and soil is >50F.  Move the plants carefully from the pots or flats and set them in the transplant holes. Set the transplants slightly deeper that it had been growing, burying some of the stem in the ground. Pack the soil loosely around the plant. Leave a slightly sunken area around each plant to hold water.  Water the plants after planting. Or, plant 1/4 inch in soil after danger of frost has passed in Spring in at least 70F temperature, well-draining soil. Seeds can be sown year-round in pots. Staking the plants can prevent them from collapsing in adverse weather. Pinch out leaves as you need them and remove flower heads to keep plants producing vigorous leaves.

Planting Depth: 1/4 inch
Within-Row Spacing:
12 Inches
Between-Row Spacing:
2 Feet


Care During the Season:

Watering: Water plants moderately. If the soil moisture is low, water but avoid waterlogging soil.

Weeding: Keep plants free of weeds, which rob weak root systems of nutrients and moisture.

Insecticides: Insecticides may be used to protect plants. Bt-based insecticides and sulfur are organic options that can be used for prevention. Sevin is a synthetic option. Sulfur also has fungicidal properties and helps in controlling many diseases. Before using a pesticide, please read the label and always follow cautions, warnings and directions.

Diseases: Disease can happen in cloudy, damp weather. Check plants daily and treat with an approved fungicide if diseases do appear. Neem oil, sulfur, and other fungicides are available for use. Please always follow label directions.


Basil is harvested when flowering begins but the plant can be harvested at any stage of growth. Trim often throughout the growing season to keep basil plants bushy. Harvest whole plants by cutting plants 4-6 inches above the ground.


Nutrition Facts:


Calories 1
% Daily Value*
Total Fat 0 g 0%
Saturated fat 0 g 0%
Polyunsaturated fat 0 g
Monounsaturated fat 0 g
Cholesterol 0 mg 0%
Sodium 0 mg 0%
Potassium 16 mg 0%
Total Carbohydrate 0.1 g 0%
Dietary fiber 0.1 g 0%
Sugar 0 g
Protein 0.2 g 0%
Vitamin A 5% Vitamin C 1%
Calcium 0% Iron 1%
Vitamin D 0% Vitamin B-6 0%
Cobalamin 0% Magnesium 0%
*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.