A tropical evergreen tree in the Myrtaceae family, cloves love warm, humid weather. This popular culinary spice comes from the dried immature flower buds (not seeds, as one would think) from these trees and originated on eastern Indonesian islands before quickly spreading to other tropical climates and greenhouses across the globe for cultivation. Leaves and bark emit the same strong aroma as the flower buds. In the wild, trees can live for over 100 years and reach close to 90′ in height, with the oldest specimen claimed to be over 300 years young. It offers medicinal uses in addition to its role in cooking. If allowed to set, olive-shaped fruits will produce one seed, which needs to be planted quickly after harvest: dry seeds won’t germinate.
Seed: Remember: the spice clove is not actually the seed! Clove seeds require soaking in water for up to 3 days before planting. Seeds don’t remain viable for planting for very long after their harvest, and dried ones will not germinate. Seeds are best started in compostable pots and repotted or transplanted as they grow.
Seed Depth: 1″
Space Between Plants: 2″, thin or transplant to 10–25′
Space Between Rows: 4–6″, thin or transplant to 10–25′
Germination Soil Temperature: 75–85°F
Days for Germination: 21–84 days
Sow Indoors: 4–6 weeks before last frost
Sow Outdoors: After all danger of frost has passed.
Vegetative: Trees can be propagated by air layering (done in the spring), or by taking stem cuttings of younger growth (anytime from spring through late summer). Clove trees are also commonly grafted.
Grows best in a wet, tropical climate with temperatures over 50°F. Trees will grow from sea level up to 3000′ in altitude. It’s native to eastern Indonesia and is now grown in tropical regions of Asia, Africa and the Americas. If you live in a cooler climate, you will need to provide the tree with tropical conditions year round in an indoor growing space.
Natural: Provide young trees with partial shade. You can use shade cloth/structures or plant cloves under banana, cassava, or other fast-growing shade trees. After trees are 3 years old, they can gradually adapt to full sun without harm.
Artificial: Grows well under fluorescent or LED lamps when young. To promote flowering and fruiting, switch to an HID lamp. We recommend HPS.
Soil: Prefers a well-drained, loamy soil. Deep and fertile soils are best for the tree, and good drainage is the most essential factor.
Soilless: Use a soilless mix containing coco coir and perlite for seed germination or for container-grown plants.
Water: Requires moderate to high levels of water. Clove prefers a moist climate and needs consistent soil moisture; however, it will not tolerate waterlogged soil.
Nutrients: Requires moderate levels of nutrients. Sidedress with manure or compost once per year, increasing the amount as the tree grows, with mature trees over 15 years of age getting about 100 lbs. Dig a trench 2–3 feet away from the trunk and add manure to allow the nutrients to filter down to the roots. Phosphorus, nitrogen, and potash additions are also beneficial biannually, once in early summer and once in fall.
Pruning: Remove dead or diseased branches once or twice per year. You can also thin branches to prevent overcrowding.
Mulching: Use mulch to suppress weeds, maintain soil moisture, and improve soil organic matter.
Rotation: Because clove trees can live for up to 100 years, you will not practice crop rotation.
Companions: Young plants grow well with shade from banana, cassava, or other quick-growing leafy trees. You can intercrop with legumes to suppress weeds and improve soil fertility. Clove also grows well with mango and jacaranda trees.
Harvest: Trees will not begin to produce until 5–10 years after planting. When flower buds begin turning from green to pink but before the flower opens, they are picked from the tree and dried in the sun until brown.
Storage: Dried cloves keep well and retain their pungent flavor for a long time. Store whole or ground in an airtight container out of direct light.
History: Cloves were introduced as a spice to the Middle East and Europe as early as 1700 BCE. The high price of cloves in Europe in the 18th century (based on the high cost and difficulty of importing them) led to the exploration of new trade routes. Eventually, the plants spread to other islands of the Indian Ocean and into Africa and South America.
Preserve: Cloves are traditionally dried in the sun after harvest. You could also use a dehydrator or oven set to low. They are used in pickling recipes as a flavoring agent.
Prepare: Used in a broad range of savory dishes and desserts, including fruit salads, baked goods, soups, curries, and more. The flavor is very strong, especially if added to food after grinding into a powder, so be careful not to use too much. Cloves can also be used in making teas or added to wine or apple cider for a warming wintery treat. If you have whole cloves and need the ground spice powder, a mortar and pestle or coffee grinder both work well.
Nutritional: Provides vitamin(s) K, C, manganese, magnesium, calcium, and fiber.
Medicinal: High in flavonoids, including eugenol, clove provides a variety of health benefits. It’s considered to have antibacterial, antiviral, antifungal, antiseptic, and antispasmodic properties. Clove oil is useful as an anesthetic and was used for dental surgery in the past and for toothaches and gum disease today. It’s also useful for promoting blood circulation and helping with a range of digestive issues. Topically, it can be used to treat skin sores, muscle spasms, arthritis, or as an insect repellent. As a tea, it will help to reduce couching and calm an upset stomach. You can even eat young flowers to freshen your breath.
Warnings: Although cloves have some anti-cancer effects, the eugenol found in clove oil may also be a weak tumor promoter in some cases. If you have a history of cancer, avoid using cloves in medicinal amounts or consult your doctor first. Clove oil in its pure form is very potent, so it is a good idea to dilute it with other oils before use, especially for younger people or those with sensitive skin. Always test your skin or gums using small amounts before committing. It is also recommended to avoid use during pregnancy.
Make some Fragrant Rice with Cloves to pair with your favorite Indian style curry.