Have you ever considered growing your own coffee? It may not be easy, but it is possible! Discover all there is to know about coffee plants, the different varieties and how to grow them.
Although coffee normally grows in tropical climates, it is possible for the plant to thrive here in the UK too. With the right conditions and care, you may even be able to harvest coffee cherries and extract the beans yourself. Here we will show you where to grow your coffee plant and what you should consider when planting.
- Coffee plant: flowering, origin and characteristics
- Coffee plant species and varieties
- How to grow coffee plants
- Coffee plant propagation
- Overwintering a coffee plant
- Is the coffee plant poisonous?
Coffee plant: flowering, origin and characteristics
The coffee plant (Coffea) is not just for coffee lovers – the Coffea flowers and leaves make surprisingly beautiful houseplants too. Coffee belongs to the Rubiaceae family and is now found in almost all tropical and subtropical regions of the world, where it is cultivated on plantations as an extremely valuable crop. In nature, coffee trees grow up to 8 metres high. As houseplants, however, they will only reach a maximum of 2 metres tall.
Coffee plants have large oval, pointed leaves with a shiny surface and wavy edges. They flower in April and May. The flowers are white, smell pleasantly of jasmine and are found in clusters in the leaf axils (the point where the leaves meet the main stem). Depending on whether the coffee plant was grown from a cutting or seed, it can take anywhere from two to four years before it begins to flower. After successful pollination, the fruits form. These fruits, known as coffee cherries, start out green and later turn red. It can take a whole year for the coffee cherries to ripen and turn red to dark purple, but in ideal conditions, the fruits can ripen after just nine months.
From this point on, the coffee plant is ready to harvest. The cherries contain two seeds known as the coffee beans which are light brown or white and only turn dark brown when roasted. After roasting, the coffee beans are ground to then be made into the much-loved morning brew. Coffee is a popular stimulant due to its caffeine content which helps wake us up and often boosts our mood. With the right coffee plant care and a little luck, you too can harvest your own coffee beans.
Tip: With constant, consistent lighting, the coffee plant can flower and bear fruit all year round. In our climate, however, you would end up using an enormous amount of energy for such intensive lighting.
Coffee plant species and varieties
Of the approximately 124 different Coffea species, Coffea canephora, also called “robusta”, and Coffea arabica are the most widely cultivated species commercially. These species are also those often kept as houseplants.
- Coffea arabica: Also known as Arabian coffee, this species grows naturally in highland regions above 1000 metres altitude. Arabian coffee is self-pollinating, so it is ideal for growing your own coffee beans at home.
- Coffea arabica ‘Nana’: You will often find this dwarf coffee bush in shops, as it does not get any bigger than 150 cm and grows rather compactly.
- Coffea canephora: Better known as Coffea robusta or robusta coffee, Coffea canephora is a lowland coffee that can tolerate warmer temperatures and higher levels of humidity. However, even robusta coffee does not tolerate temperatures above 30 °C.
- Coffea liberica: This species can also be kept as a houseplant. The leaves of Coffea liberica are slightly lighter than those of other species and it usually has a slightly wilder and untidier appearance.
How to grow coffee plants
Have you ever wondered, while sipping your cup of morning coffee, whether it is possible to grow your own coffee plant? Well, yes, you can! And it is not even that difficult to grow your own coffee – you can grow coffee plants from seeds or cuttings (or even just buy yourself a small, already established plant from a shop).
The right location for your coffee plants
Coffee grows naturally in tropical highlands and requires similar conditions when grown here in our climate. So, cultivate your coffee plant in a pot and only place it outside in summer in a shady spot. In winter, keep your coffee plant indoors, ideally somewhere bright, warm and humid. Coffee plants do not tolerate direct sun well, so place it near an east or west facing window where it will get a few hours of sun in the morning or evening. It requires consistent temperatures of around 20 to 25 °C all year round with as little fluctuation as possible. Even in winter, do not let the temperature drop below 15 °C. High humidity is also important for a healthy coffee plant. To boost humidity, spray the leaves with water regularly or place the pot on a shallow dish with pebbles and water.
It is also possible to cultivate coffee plants in a jar, which you can either buy or make yourself. To make a coffee plant terrarium, take a tightly closing glass jar, like a Kilner jar, and add a layer of expanded clay to the bottom for drainage. Add a layer of suitable soil and then the coffee plant. Cover the remaining soil with moss. Now water everything well, but do not soak it. Close the jar and put it in a bright place with no direct sunlight.
For a kokedama coffee plant (coffee plant rooted in a mud ball coated with moss) mix one part peat with one part clay and moisten everything well so that the mixture can be shaped but is not sludgy. Then take a small coffee plant from its old soil and dip the root ball in water. Cover the root ball with the peat and clay mixture and carefully press everything together. Now drape a dry sheet of moss around the peat and clay ball and wrap with string until everything is firmly in place. A kokedama hung up with some twine is a stunning decoration. To water, simply spray the moss ball with water from the outside.
You can also grow coffee plants hydroponically, which is when the plant is put in a planter filled with expanded clay balls rather than soil and a nutrient solution. Hydroponic growing is very simple and ensures good humidity. However, we generally do not recommend hydroponics as it is a less environmentally friendly option. This is because it usually requires mineral fertilisers instead of sustainable, plant-based fertilisers.
Tip: The three alternative methods for growing coffee plants mentioned above help to increase the humidity around the plant.
What kind of soil to use for coffee plants
If you decide to grow coffee plants in soil, it needs to be permeable. Opt for a slightly acidic, nutrient and humus rich soil that contains a low amount of peat and can store water well without becoming waterlogged. For even better drainage, mix your coffee plant soil with 30% expanded clay or sand.
Tip: To keep the soil moist, cover it with a layer of mulch. This prevents water loss through evaporation. We recommend using a slightly acidic pine bark.
Coffee plants as houseplants
If you wish to keep your coffee plant indoors, water it regularly and make sure it has good drainage. Coffee plants do not tolerate waterlogging as this can quickly lead to root rot. Choose a deep pot so that the roots have enough space to grow. Add a drainage layer of stones or expanded clay at the bottom to prevent the coffee plant from sitting in water. Then, to meet the coffee plant’s water requirements, water it daily so that the soil is always moist but never waterlogged.
In order to be able to harvest fruit from coffee plants, we recommend you assist in pollinating the flowers. Although Coffea arabica is self-pollinating, a little help won’t hurt. To do this, simply take a fine brush and carefully rotate it in each flower.
Last but not least, to accommodate the coffee plant’s relatively high humidity requirements, place it somewhere like a bright bathroom, for instance, where there is usually plenty of moisture in the air. Living rooms, on the other hand, are often too dry for coffee plants.
Can you grow coffee plants outdoors?
In summer, you can put your coffee tree outside. Place it in a sheltered spot in partial shade, preferably under a larger plant, and spray with water from time to time. However, if temperatures fall to less than 15 °C at night, bring your coffee tree back indoors.
Coffee plant propagation
There are two ways to propagate coffee plants. If you already have a plant, you can take cuttings. Alternatively, you can propagate from seed – either shop bought or seeds collected from your own plant. However, when growing coffee plants from seed, the seeds must be fresh as their germination capacity diminishes quickly and disappears completely after about two months. Roasted coffee beans are, of course, no longer viable.
Propagation from seed
To grow coffee from seeds, first soak the seeds in water for about 24 hours at a temperature of around 25 to 30 °C – use a thermos flask to maintain this temperature. To sow the seeds, first fill a container with suitable soil. Next, place the coffee seeds about 1 cm deep in the soil and moisten it slightly. Place a plastic bag over the seeds and keep the container warm at a minimum of 23 °C. It takes about four weeks for the seeds to germinate. During this time, keep the soil slightly moist and air out the plastic bag daily to prevent mould from developing. After that, place the tray in a bright location so that the seedlings can continue to grow before eventually being transplanted.
Propagation with cuttings
Take coffee plant cuttings in spring when the growth period is just beginning. The cutting should be taken from the tip of the central shoot so that it continues to grow straight up. When doing this, make sure the shoot section is not yet woody, has no buds or fruit and already has two to three leaves. Remove all remaining leaves from the 8 to 20 cm long shoot section.
Put each cutting into its own pot with soil and keep it moist. Choose a bright and warm spot with temperatures of 24 to 28 °C. Placing a plastic bag over the cuttings increases humidity and the chances of successful propagation – but be sure to air it out regularly. Roots should form within two to three months.
Overwintering a coffee plant
As coffee plants are not hardy, do not leave them outside in winter. Instead, overwinter your coffee plant in a bright and warm place at around 20 °C. As the air is drier in winter, ensure the plant has sufficient humidity. The best way to do this is to place a bowl of water on a radiator near the coffee plant. Alternatively, spray your coffee plant regularly with water. Cut down on watering and stop using fertiliser in winter as coffee plants hardly grow during this time.
Is the coffee plant poisonous?
The coffee plant is not poisonous to humans but can be dangerous for pets if ingested. Cat owners should put the coffee plant somewhere out of the cat’s reach to be on the safe side. If eaten in large quantities, the coffee cherries can cause vomiting or diarrhoea in pets due to their caffeine content. The leaves, however, contain only very small amounts of the active ingredient and are harmless.
Fact: In nature, caffeine benefits the coffee plant as it inhibits the germination of other plants in the vicinity and discourages predators from eating the leaves and fruits.
Now that you know how to grow your own coffee plant, it’s just a matter of looking after it. Learn everything about coffee plant care in our dedicated article.