In their native habitat, coffee plants grow into medium-sized trees. But growers regularly prune the plants to be a more manageable size, especially when the plants are grown indoors. (Note that you can’t grow coffee plants from the beans you buy in a store; those have been treated and roasted and will not sprout.) Even though coffee plants are vigorous growers, it will typically take a few years before your plant produces flowers and subsequent fruits. Other than the seeds, it’s important to know that all plant parts are toxic to both humans and animals. You can grow coffee plants outdoors if the conditions are similar to their natural environment. Indoors, coffee plants do best placed near a window but not in direct sunlight. Make sure to keep the plant away from drafts, such as those produced from air conditioning. Be prepared to water at least weekly to keep the soil moist.
Light
Coffee plants prefer dappled sunlight or full sunlight in weaker latitudes. They are actually understory plants (existing under the forest canopy) and do not thrive in direct, harsh sunlight. Coffee plants that are exposed to too much direct sunlight will develop leaf browning.
Soil
Plant coffee plants in a rich, peat-based potting soil with excellent drainage. Coffee plants prefer acidic soil, so if your plant is not thriving add organic matter such as sphagnum peat moss to lower soil pH. The ideal pH range is closer to 6 to 6.5.
Water
These plants are water lovers and require both regular and ample watering. The soil should stay evenly moist but not waterlogged. Never allow the soil to dry out completely.
Temperature and Humidity
The optimal average temperature range for coffee plants is a daytime temperature between 70 to 80 degrees and a nighttime temperature between 65 to 70 degrees. Higher (hotter) temperatures can accelerate growth, but higher temperatures are not ideal for growing plants for their beans. The fruits need to ripen at a slow, steady pace. In addition, because these plants naturally grow on the sides of tropical mountains, they thrive in highly humid conditions which usually receive plenty of rain and fog. A humidity level of 50 percent or higher should suffice. If the air is too dry, the leaf edges might start to brown. Mist the plant daily to raise the humidity level.
Fertilizer
Feed with a weak liquid fertilizer throughout the growing season every couple of weeks. Cut the fertilizer back to once a month or so in the winter.
Types of Coffee Plant
Coffea arabica ‘Nana’: This is a dwarf variety that only grows 12-inches tall, making it ideal to cultivate indoors. Coffea canephora: Commonly known as robusta coffee, this species comes from sub-Saharan Africa. Its plants are robust; however, the coffee beans are less favored because they tend to have a stronger, harsher taste than arabica beans.Coffea liberica: A variety native to central and western Africa, it was first discovered in Liberia. It produces large fruits with a higher caffeine content than arabica beans, but lower than robusta beans.
Pruning
Coffee plant needs little pruning, but should be cut back in the spring with clean, sharp gardening shears. This will help shape your plant, and it will grow back bushier!
Propagating Coffee Plants
To propagate coffee plant, you can do so from cuttings or air layers (a somewhat involved technique where you root branches still attached to the parent plant). The best time to take a cutting is in the early summer.
How to Grow Coffee Plant From Seed
While you can’t germinate the coffee beans you buy in a store, you can sprout the ones that grow on your coffee plant. Called “cherries,” the fruit should be picked when they’re a bright crimson color. Rub away their flesh and wash away any residue to release the seeds or beans; dry them thoroughly by sitting in the open air for a few weeks. Then, soak the beans in water for 24 hours (toss any that float), and sow in damp, but well-draining, sand. If you water daily, the beans should germinate in two to four months. When they’ve germinated, carefully remove them and plant each one in well-draining, acidic soil. Water twice a week.
Potting and Repotting Coffee Plant
Repot your coffee plant every spring, gradually stepping up the pot size. Make sure the container has several drainage holes. If you want, you can prune the plant to the desired size, slightly restrict its pot size, and root prune to keep its growth manageable.
Common Pests & Plant Diseases
Coffee plants grown indoors will sometimes suffer from infestations of mealybugs, aphids, and mites. Signs of infestation include tiny webs, clumps of white powdery residue, or visible insects on the plant. Treat infestations with insecticides, or something organic like neem oil. as soon as possible to prevent them from spreading to the rest of your collection.
How to Get Coffee Plant to Bloom
Coffee plants bloom delicate, white flowers, once the plant is around three-years-old. If these blooms are pollinated—if your coffee plant is outdoors—the flowers will give way to little, red fruit (the “cherries”) that are slightly soft to the touch. To get your own coffee plant to bloom, make sure it’s at the right temperature—70 to 80 degrees Fahrenheit during the day—has four to five hours of sunlight a day, and is growing in damp, well-draining soil.
Common Problems With Coffee Plant
Brown spots on leaves
Fungal diseases like leaf spot can give your coffee plant brown spots on its leaves. To remedy, remove affected leaves and stems and trim away inner branches so there is better air circulation for your plant.
Brown leaves that fall off
Leaves that turn brown and fall off usually do so from leaf scorch (otherwise known as “too much sun”). Fixing the former is merely a matter of giving your coffee plant more indirect light.
