Coffee, sun or shade? The definitive guide

[KarenRei]

Ran into a very interesting paper researching coffee productivity (was actually searching for artocarpus response to light at the time, but I'll take it!)

http://corridor.bangor.ac.uk/documents/treesoncoffeeplantationsreport.pdf

Key takeaways:

 * Photosynthesis rates of sun-adapted leaves are about 80% at 500 umol/m²/s, 90% at 750 umol/m²/s, and 100% at 1300 umol/m²/s. Full sun is around 2200 umol/m²/s; the extra sunlight only serves to inhibit photosynthesis
 * This is amplified by means of the fact that coffee leaves live longer in shade, and thus less energy needs to go into their production
 * Opposing this, however, is real-world data showing that coffee production is higher in the sun than the shade - multi-year yields are just under 80% of max in full sun, 100% in 75% sun, a bit over 80% in 50% sun, and around 30% of max in 25% sunlight.  "Good year" yields are even better for full sun - nearly as good in 100% sun as 75% sun, and nearly 4 times more in full sun than 25% sun.
 * The reason for this is that the internode length increases in the shade, and thus fewer flowers are produced (note: not discussed in the paper, but if one wants to counter this, blue light is known to reduce internode distances).
 * Somewhat (but not significantly) offsetting this is lower fruit drop in shade coffee.
 * Because energy is abundant in shade coffee, but full sun coffee produces more fruit, shade coffee yields a higher-quality fruit, while sun coffee stresses itself out to the point of resulting in a partial alternate-bearing habit.
 

[gnappi]

Ran into a very interesting paper researching coffee productivity (was actually searching for artocarpus response to light at the time, but I'll take it!)

http://corridor.bangor.ac.uk/documents/treesoncoffeeplantationsreport.pdf

Key takeaways:

 * Photosynthesis rates of sun-adapted leaves are about 80% at 500 umol/m²/s, 90% at 750 umol/m²/s, and 100% at 1300 umol/m²/s. Full sun is around 2200 umol/m²/s; the extra sunlight only serves to inhibit photosynthesis
 * This is amplified by means of the fact that coffee leaves live longer in shade, and thus less energy needs to go into their production
 * Opposing this, however, is real-world data showing that coffee production is higher in the sun than the shade - multi-year yields are just under 80% of max in full sun, 100% in 75% sun, a bit over 80% in 50% sun, and around 30% of max in 25% sunlight.  "Good year" yields are even better for full sun - nearly as good in 100% sun as 75% sun, and nearly 4 times more in full sun than 25% sun.
 * The reason for this is that the internode length increases in the shade, and thus fewer flowers are produced (note: not discussed in the paper, but if one wants to counter this, blue light is known to reduce internode distances).
 * Somewhat (but not significantly) offsetting this is lower fruit drop in shade coffee.
 * Because energy is abundant in shade coffee, but full sun coffee produces more fruit, shade coffee yields a higher-quality fruit, while sun coffee stresses itself out to the point of resulting in a partial alternate-bearing habit.

Until recently I had 11 coffee trees. Three in full sun, eight in mostly shade and the shaded ones outproduced the ones in full sun 2 to 1. Both did very well as far as putting out new growth. I removed them all this spring because I had thousands of little coffee plants growing under them and I couldn't keep up with pulling them all out.
 

[KarenRei]

The sun of course isn't the only factor; plants can also be stressed by the sun if water is insufficient, nutrient availability / soil quality can have an effect, etc.  But in terms of the plant's fundamental ability to utilize energy, and to produce flowers (and thus berries), a coffee plant just can't make use of more than about half sun, and the only reason that (in optimal conditions) they'll produce more in the sun is because of the shorter internode distance - but this comes at a cost of them exhausting themselves and producing inferior fruit.

It's really amazing how little energy coffee can get by on.  I have some coffee plants fruiting on the light from a north facing window.  They don't yield much, of course, but... fruit from a north-facing window in Iceland, that really says something 

[Finca La Isla]

There’s quite a bit of coffee grown in full sun in Costa Rica.  I think most believe that shade grown is better though what you see as shade grown looks pretty sunny to me.  The more sun the more fertilizer is fundamental. So it’s more expensive to grow in full sun.  Nobody would do it if it didn’t have a higher yield, which it does with the higher applications.
Peter

[palmcity]

... fruit from a north-facing window in Iceland, that really says something 

lol  I can't help but wanting to answer the Something for a few who may be unaware of the Earths Tilt...
Jun 9   3:05 am Sunrise------11:49 pm Sunset (Reykjavik)

[fliptop]

gnappi, did you ever make your own coffee?

Prior to thoroughly researching growing coffee in FLA, I ordered seeds and have some sprouting now.

Any specific advice for growing them in ground in FLA zone 10? I will keep some as house plants, as well.

Thanks!

[luketrollope]

Sorry to be a pain but better to mention that your talking about  Coffea arabica and not Coffea canephora which is a lot hardier and has different sun requirements  and is a lot easier to grow and harvest hence it's other name "robusta".

[gnappi]

gnappi, did you ever make your own coffee?

Prior to thoroughly researching growing coffee in FLA, I ordered seeds and have some sprouting now.

Any specific advice for growing them in ground in FLA zone 10? I will keep some as house plants, as well.

Thanks!

I made coffee for a few years. Each tree/bush was sufficient to give me 3 to 4 weeks worth of coffee. The plan was to have 13 trees (enough for approximately a year) so I could stop buying store bought coffee.

Unfortunately the cherries are too labor intensive to turn into coffee so that in concert with the many seedlings that sprouted and the variability in the finished drinkable product  I pulled them all.

As far as growing them goes, I have pretty good sandy / loamy soil which I try to keep covered with 8-12 (or more) inches of mulch, water with iron free well water as needed, and only fertilize with the Excalibur fertilizer also when needed or as I thought about it, I didn't do it on any schedule. Mine needed little care other than this as they are disease and pest free here in Coral Springs.

PS, the coffee was generally outstanding for the first years but the last year not so good. 

 

 

[KarenRei]

... fruit from a north-facing window in Iceland, that really says something 

lol  I can't help but wanting to answer the Something for a few who may be unaware of the Earths Tilt...
Jun 9   3:05 am Sunrise------11:49 pm Sunset (Reykjavik)

Yeah, but try looking at what the sun is like on Jan 9   

[Mike T]

Coffee plants from fruit spread by birds has gone a bit feral in some places in my district. The coffee plantations that were the source disappeared decades ago but plants can be found in nearby rainforest areas as an understorey plant in shade or dappled light.They are not super-productive and are often lanky .

[KarenRei]

Note that true understory environments in a dense rainforest environment are - excepting light flecks - under 1% of the light intensity of the canopy, sometimes much less.  Light flecks are very important for understory species, and part of the reason why they tend to develop large leaves is to increase their odds of encountering them. That's the leading theory at present for why, for example, Monstera leaves are full of holes; it lets them make a larger leaf with the same amount of material, increasing the odds that they'll catch at least part of a light fleck (without the holes, they'd get more energy from a given fleck, but they'd encounter them half as often). 

Basically, there's a big difference between growing coffee in 25-50% sun and growing it in 1% sun!    Of course, I don't know how dense the environment is near you.

[sahai1]

the more sun, the nuttier the flavor.  I think many people in this forum can comment on Kauai coffee.  That is all the evidence you need to see about how why shade is different, and in some opinions better.

In my opinion, the nutty flavor overpowers all the subtleties of good coffee.  I can drink partial shade, but if talking about the wild sprawling coffee bushes under the canopy of 30 meter + trees, that is the best coffee in the world.  They harvest some coffee in Maui like that, used to or still have a roaster in Paia.

I have start to set up my coffee and have interspaced coffee between Artocarpus Lakoocha, and will do another section soon interspacing between Pedelai.  Artocarpus 4-5 meters between, then coffee at 2-2.5 in the middle.  I've also planted coffee in many spaces which I believe no other tree will thrive due to sunlight issues.  If I increased the spaced I could do Cacao, but I've already planted cacao inbetween the coconuts which can be spaced at 2.5-3 meters while still allowing lots of sunlight.

[DaveT]

The more sun, the more coffee will produce. The more they produce, the more water and nutrients they need. If coffee doesn't get the desired nutrients (water or fertilizer) then they will start to die back. Once coffee trees set fruit they are very reluctant to drop their babies when under stress.
When planted in shade, they set much less fruit but are much more likely to survive without assistance.

[Daintree]

I think it also depends on your natural cloud cover.  In the tropics, "full sun" includes a lot of clouds, which helps keep the soil cooler than here in SW Idaho, where we are high desert, and may not see a cloud for three months.  Tropicals in full sun here are scorched to a crisp in a week, poor things!  I quit hauling my plants in and out of the greenhouse in the summer because it just took too long for them to adapt to the pounding rays of the sun, then to adapt to the more shaded greenhouse in the fall. Plus, they picked up "hitchhikers" that I don't want in my greenhouse.  They stay in the greenhouse all year long now, and are much happier. 

Incidentally, I spent the entire last year picking and processing my coffee, only to discover that my roasting skills are HORRIBLE.  I burnt a lot of coffee, under-roasted some and had to roast it again, and finally decided it wasn't worth the effort.  But in case of a zombie apocalypse, I will make a fortune selling the only fresh coffee in Idaho!

[fliptop]

gnappi and Daintree, thank you for posting your experiences growing/making coffee.

If not a presumptuous request, can you give insight on how you take berry to cup? Or, is there a specific website/video/book/? you found particularly helpful you'd recommend to learn the ways?

Also, have you eaten the berries and if so, how did you find them?

Incidentally, one of the coffee seed types I bought from Trade Winds was Coffee racemosa. Their description did not include the information that C. racemosa is naturally decaffeinated. GRRRRRRRR.

Thanks again!

[Zafra]

gnappi and Daintree, thank you for posting your experiences growing/making coffee.

If not a presumptuous request, can you give insight on how you take berry to cup? Or, is there a specific website/video/book/? you found particularly helpful you'd recommend to learn the ways?

Also, have you eaten the berries and if so, how did you find them?

Incidentally, one of the coffee seed types I bought from Trade Winds was Coffee racemosa. Their description did not include the information that C. racemosa is naturally decaffeinated. GRRRRRRRR.

Thanks again!

https://www.daf.qld.gov.au/business-priorities/plants/fruit-and-vegetables/specialty-crops/coffee-processing-in-the-home
http://www.ncausa.org/About-Coffee/10-Steps-from-Seed-to-Cup

[Daintree]

Zafra, those are great links! That is pretty much what I do for my coffee.  The only thing is that I get the grandkids to help me pop the seeds out of the fruits.  They LOVE to do that, and will sometimes see how far they can "shoot" the seeds.  Makes a mess, but we can get through a big batch that way.

I love the coffee cherries, and eat them frequently when I am out in the greenhouse puttering around.  To me, they taste like slightly sweet celery. I tend to eat them seed and all, since the seeds are softer before drying.  Yummy!  They do have caffeine in them, but don't know how it compares to roasted beans. Mine are Kona arabica beans. Never tried any others.