Coffee

I've seen and heard of people boasting (and with good reason) about growing citrus fruit in areas where such things don't normally grow, in greenhouses. Has anyone managed to grow coffee beans? Because then I'd be *really* impressed!

If you can create the optimal conditions you can grow anything anywhere.

That is a big if though.

As you mentioned, outside of it's normal range coffee is usually grown in greenhouses. Just a quick internet search came up with this: https://www.growingreenhouse.com/can-i-grow-coffee-in-a-greenhouse-is-coffee-worth-it/

They mention not needing full sun, rather preferring filtered sunlight, which is an interesting point for permaculture gardening. That means even in a greenhouse you could potentially layer coffee under another tree. You'd need a reasonably tall greenhouse though.

The optimal conditions for coffee (from another site):

Arabica being tropical in nature, requires that the plant receives 1,200-2,200 mm of rainfall per year and grown at an ambient temperature of 15°-24°C. Depending on the species, coffee plants can grown to a height of 2.5-4.5 meters, though shrubs are typically pruned to 2-2.5m for easier harvesting.

Robusta on the other hand requires slightly more rainfall (2200-3000 mm/yr) and can grow up between 4.5-6.5m in height.  

I found another thread that may be of interest to you:

https://permies.com/t/21750/Growing-coffee-cold-climates-greenhouse

There's a fair amount of discussion about selecting for hardier varieties with the aim of growing without a greenhouse. As well as alternative caffeine sources such as Yaupon holly and Camellia sinensis.

Nancy Reading wrote:I found another thread that may be of interest to you:

https://permies.com/t/21750/Growing-coffee-cold-climates-greenhouse

There's a fair amount of discussion about selecting for hardier varieties with the aim of growing without a greenhouse. As well as alternative caffeine sources such as Yaupon holly and Camellia sinensis.

Thank you - I'll check it out!

You can grow A coffee tree and get one cup or two of coffee a year from it, but to grow enough to sustain your habit takes a BIG greenhouse.