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Basil Growing Guide

Basil Growing Guide

SHORTCUTS: Ideal Environment, How to Plant, How to Water, Companion Planting, How to Propagate, How to Harvest, Parts Used, Preparations, Uses, Key Constituents, Key Actions, Research.


Ocimum basilicum
Information Basil is a green or red herb with a unique sweet yet sharp taste, its subtle liquorice flavour is earthy, full, and fresh. Most varieties are treated as annuals but some are perennial in warmer climates. There are many varieties and related species or species hybrids also called basil. The type used in Italian food is typically called sweet basil. Others include Holy Basil and Lemon Basil.

Growing Environment

Ideal Environment 

Basil prefers full sunlight (6+ hours) and a warmer climate (15 degrees C and up), so it is best to start them indoors (3 weeks before the last frost) if it is cooler.  They like well drained soil, compost and will grow in a wide range of soils (pH levels between 5.1 and 8.5), between 5.5 and 6.5 is considered ideal.

How to Plant

How to Plant 

Sow basil seeds thinly and covered with approximately 0.2 – 0.5 cm of compost or good soil. Germination occurs about a week later. Once the seedlings have two pairs of leaves they can be thinned out. Plant at least 30 x 30cm apart, or one plant per pot.


How to Water

Basil generally likes to have moist soil (not soggy because over-watering isn’t good either), I do not let the soil dry out, especially when they are young, once they are more established they can be watered twice a week. Water around the plant and not the leaves.  

Companion Plants

Companion Planting 

Basil helps tomato, peppers, oregano, asparagus, onions, chives, parsley, carrots, nasturtiums and petunias.  Basil is helped by chamomile and anise because it is said to increase their oils, and it is possible that growing them close to alliums (onion family of plants) can repel insects and rodents.  

Do not plant basil with plants that require little water.

Here are the Companion Plants by group: Herbs, Flowers, Trees, Vegetables, Berries, Fruit and Mushrooms

How to Propagate

How to Propagate 

Basil can be purchased as seedlings in plugs and pots ready for planting but they are easy to grow from seeds or cuttings placed in water.  To harvest your own seeds for next year you can let some of your plants go to flower, cut the flowering stems when they have dried up (usually turning brown), then rub the stem between your hands to break open the pods and release the small black seeds. Store seeds in a cool and dry place, ideally in an air tight container or packet.


How to Harvest

Start using the basil leaves as soon as the plant can spare some and collect from the tops of the branches, cutting off most of the stem. They bruise easily so handle carefully.

Use basil when it is fresh, and if you have extra you can make a puree (by adding a little water) and freeze them for use in sauces, soups, pesto etc. Basil pesto can also keep in the fridge for a week or so, ensure that there is a thin layer of olive oil ontop.

Medicinal Plants Parts Used

Parts Used

The leaves are usually used fresh or dried.

The seeds are also soaked and used in drinks, but I have not found scientific research about their constituents.

Medicinal Preparations


You can make basil infused oil, pesto or just use fresh leaves. Holy basil (Ocimum sanctum) is said to be more medicinal but sweet basil is a close relative. Preparations for holy basil include a juice for skin infections (1oml applied to the affected area twice a day, a decoction is used for fevers and the powder can be used to rub into mouth ulcers (1).

Plant Uses


It is easiest to use basil as a culinary herb in food. Holy basil is said to be used for diabetes (reduce blood sugar levels), to improve vitality, used in reducing fevers, infections and in reducing stress (1).

Cooking options are virtually unlimited with fresh basil, always add your fresh Basil at the last minute to preserve the full flavour. Tear the leaves rather than cutting them because they discolour easily. Basil flavours combine really well with tomato, garlic and eggplant, and works great in soups, stews and sauces.

Basil can also be an insect repellent, rub crushed leaves on the skin and keep a potted basil plant in the kitchen to keep flies at bay.


Key Constituents

Basil contains various volatile oils like Eugonol and Camphene. Basil is also said to be rich in antioxidant vitamins and phenolics, and a source of Protein, Vitamin E (Alpha Tocopherol), Riboflavin and Niacin, Vitamin A, Vitamin C, Vitamin K, Vitamin B6, Folate, Calcium, Iron, Magnesium, Phosphorus, Potassium, Zinc, Copper and Manganese (9).

Key Actions

Key Actions

Antioxidant, antiviral and antimicrobial.



Basil (and oregano) apparently contain large amounts of (E)-beta-caryophyllene (BCP), which might have a use in treating inflammatory bowel diseases and arthritis (11). More than one scientific study has established (in vitro) that compounds in basil oil have potent antioxidant, antiviral, and antimicrobial properties, and potential for use in treating cancer (10).

USEFUL LINKS: About the Growing Guides, The Medicine Garden, Companion Plants, Basic Preparations and Plant Constituents. Disclaimer. References.