Coffee beans grow on the Coffea arabica plant which is related to gardenia, ixora and coprosma. It’s a beautiful small tree to about 5m (15ft) high with glossy green leaves and jasmine-scented white flowers that appear along the stems in summer-autumn. As the fruit develops along the stem, it starts off green and then changes to a bright red cherry-like fruit, finally maturing to a dark brown. Although coffee is a small tree, you can prune it to a 2m (7ft) shrub, which is how they’re kept in coffee plantations. This pruning also encourages lateral branching and more flowering and fruiting.
So, what sort of micro climate do you need to grow coffee? Coffee prefers temperatures between 15 and 24 degrees C (60-75F), although if it’s within the range of 7-30 degrees C (45-85F), it will still grow quite well. Choose a shady spot, sheltered from cold or hot winds. Frost is the big enemy in cooler climates, and below -2 degrees C (28F) will probably kill the plant. The good news is that home-grown coffee doesn’t get any pests or diseases.
If you’re in a cooler climate, you can certainly grow coffee in a pot, and wheel it into a sheltered position for winter months and if you’ve got a greenhouse, even better. Almost any type of reasonably good soil is OK as long as it’s slightly acid (pH6), doesn’t get waterlogged, and isn’t dry and sandy. You can even grow coffee as an attractive indoor pot plant and still expect some beans.
For garden-grown plants, it has to rain at the right time of year, which for coffee is in winter-spring. Like murraya, coffee flowering is controlled by rainfall and as little as 8mm will force a new flowering and fruit-set through spring and early summer. New rain events can trigger another flowering so you’ll often find flowers and ripening fruit on the tree at the same time, as the fruit can take 6 months from autumn right through to spring to change to red. Cooler conditions promote the longer ripening periods. While your coffee tree will tolerate dry conditions it won’t flower and fruit without regular watering.
Late spring is the perfect time to plant your coffee tree. You should get your first crop of coffee beans in about 3 years (6 years from seed) but you’ll need about 30 plants for enough beans for a daily cup. You could even think about a coffee hedge in a shady part of the garden. Six weeks after planting apply 100g of a complete citrus fertiliser per tree, and keep doing that every 6 weeks during the warmer months as coffee trees are heavy feeders. On small plants, when it’s about 500mm (20″) tall prune off the growing tip to encourage lateral branching. In many coffee plantations, heavy-cropping coffee trees are cut almost to the ground every 3 years to encourage vigorous new growth, which is then thinned and tip-pruned to restore the bushy habit.
Harvesting and preparing coffee
Inside each coffee fruit are two beans which look a bit like raw peanuts in size and shape. You can pick coffee beans as they mature to red or do as they do in Brazil where coffee fruit is left on the tree until almost all of the berries have coloured and shrivelled, and the berries are easily removed in one go, although some say this method doesn’t give you the best coffee. Research in Australia shows that fruit picked at the prime red cherry stage makes the best tasting coffee. These coffee ‘cherries’ as they’re called, are slightly tart but quite delicious to eat straight from the tree when they’re red and ripe. Harvesting in eastern Australia would be usually around November to early December.
Getting your coffee fruit to ground coffee ready for a steaming cup is a multi-stage process. First you have to remove the pulp surround the coffee beans which is a bit laborious. Then the bean is fermented to remove the sticky mucilage - soak the coffee in water for a few days until bubbles start to appear. When the beans feel gritty, they’re ready for washing.
Now, comes the drying – up to 7 days in the sun. To tell when they’re ready, the bean has to crack between the teeth. This is called the parchment stage. But wait, there’s more! The parchment and silver skin have to be removed, leaving the green bean – and that’s the bean you have to roast. You can roast them in an oven (it only takes about 10 minutes), buy a purpose built roaster or there are some companies which will roast your beans for you.
Coffea arabica is just one type of Coffea species originally indigenous to the mountains of the southwestern highlands of Ethiopia. This type of coffee, Arabica, has less caffeine, which is what gives coffee its bitter taste, so many think this is the best tasting coffee.
Legend has it that a 9th-century Ethiopian goat-herder noticed that his goats became more energetic when they ate the bright red berries of a certain bush, so he chewed on the fruit himself. He took them to a nearby monastery where the monks discovered that the burnt beans, when mixed with water, made a drink that gave them energy. However coffee as a drink wasn’t really known for centuries. Instead, as the pulp of the coffee cherry was sweet, it was first eaten alone or with the seeds (beans). In some places, the green unroasted coffee beans were ground up and mixed with animal fat. Hmmm….yum? This mixture was then pressed into small lumps and was used by travellers for energy.
Coffee trees were grown in Australia for coffee production in the early 1880s, and pretty well too, with arabica beans from the far north coast of NSW winning awards in Paris and Rome in the mid 1880s. Because of the particular microclimate conditions, Australian arabica coffee is lower in caffeine and is highly regarded for its sweetness and medium body. As there are no serious pests or diseases needing any harmful pesticides, growing your own coffee would be one the most naturally produced coffees of the world.
Where to buy coffee trees online:
Australia – the two most available varieties are K7, bred in northern NSW for its disease resistance and a dwarf variety often sold as ‘Catui’: Daleys Fruit Tree Nursery; Lush Plants Qld; Heart Garden Nursery; Go Green Rainforest Nursery. Cape Australia supply coffee tree seedlings. In South Australia, contact Perry’s Fruit and Nut Nursery.
New Zealand: Incredible Edibles
South Africa: Beaver Creek Coffee Estate