Now this is one of the finest conservatory and warm greenhouse plants you can grow. It is not quite, but almost, hardy in some varieties. Well it will survive a single short snap, but will expire if kept too cold for long.
However it does not need much heat and it’s easy to grow replacements from the fresh seeds -and you will get these within a few years- if you don‘t roast and drink them that is. Coffee comes in several varieties, Arabica and robusta are the two main categories but it makes little difference from our point of view.
I’m sorry but it is not so much the variety but where it is grown that makes a great coffee, and unless your greenhouse is in the foothills of the Jamaican Blue Mountains then you are not going to produce that sort of high quality. Still, you can grow the red ‘cherries’, strip their skins off (by part fermenting them ideally) and then dry and roast the beans or seeds inside. You will get a coffee, and probably it will not be as bad as some you have tasted. But coffee is also a really beautiful small shrub and being a shade lover it is well adapted to our dimmer climate under cover.
This small shrub can be kept small by regular pruning and can be grown in only a modest sized tub for years. It needs no special compost though not liking much lime so I use a mixture of John Innes potting compost mixed 50/50 with an ericaceous blend. Regular watering with rainwater is essential, and a weekly nitrogenous feed such as fish emulsion in the water once a fortnight in summer is straight forward.
Not particularly prone to pests coffee may suffer from mealybug or scale with the usual treatments. Once established big glossy wavy edged leaves soon give way to masses of starry white flowers, jasmine like, and similarly sweetly scented. For these alone it’s worth the space. These then ripen to the ‘cherries’. The problem for home production of coffee is not just the small numbers but that they come over weeks. They need picking and treating in lots of little batches which makes producing a fine beverage even harder. But go on have a go, the triumph is worth it! And you still get a lovely plant rivalling all others in the beauty stakes.