What is the lowest temperature Coffea plants can be subjected to before they show signs of stress or damage? I've read they suffer leaf drop when exposed to temps below 13C/55F for extended periods. Can someone with experience growing these plants verify this?
Never grown any, but one of my books says it prefers 16° to 29°, but that temperatures a little lower are not lethal, they just slow growth down a lot. It doesn't give a lethal temperature. It may also vary a bit between the different species of Coffea.
Hi, Michael. The answer varies depending on which book you read. In my experience with other plants I find their answers are often wrong thus my hope for some guidance from another grower. I was told these are the regular arabian coffee. I've been growing a number of these plants since separating them from the one 4" pot they came in. They've more than doubled in size and have leafed out quite nicely. It would be a shame to cause them harm. I could put half of them in a warmer room to hedge against total loss but then risk damaging them from low humidity. It's either that or keep a really close eye on them. The room they're in now can dip down to around 10C/50F.
The plants made it through winter lows of ~12C/54F in high humidity with minimal damage. A few trees ended up with brown leaf margins affecting approx. 1/3 of the leaf surface on the lowermost leaves. Not sure I would say that was due to the cold though since not all trees were affected. They've been putting on new leaves and branches for about a month now.
Don't know the minimum temp, but I do know that my old tree has survived a trip to Vancouver in the belly of a 737 when it was quite young, the trip back in a covered trailer two years later, a trip to Calgary in a real moving van, and the trip back in my (tarp covered) truck. Temp runs between 60 and 80 degrees in the house...the seedlings all seem to like it. I just consider leaf drop and browning part of the deal. Its a messy tree. Or maybe its not...maybe I don't treat it right.
Maybe these trees are not as fragile as the books will have us believe. This winter was somewhat warmer than normal so time will tell. I have not found the trees to be messy but then they're still quite small. They're not that leafy so how messy could it possibly be unless the mess comes from the spent flowers.
Stuff can't be very fragile in my house what with a brown thumb, a bull terrier, wood heat and limited (winter) daylight. Yes spent flowers, leaves, and the odd spot of sap or something- not very often and not predictably-at least not yet. Could be a whole lot worse though. I've got a mimosa (I think) in my window that's really messy. If I can ever figure out the scanning and stuff I'll post pictures in the appropriate places.
The mess from spent flowers was the reason why I stayed away from flowering plants for such a long time. In the beginning I just picked up the debris as I had only two such plants but decided this wasn't going to work as the number of plants increased. I now have a hand-vac that is small enough to get into tight spots. It's been great so far. It may not work as well for flowers that have a lot of sap though.
An update: The plants made it through another winter; this time with lows ~6C/43F. Results were similar albeit under lower humidity levels.
Hi, pinenut. Do you know how low it got when the stove cut out? I'm keeping my fingers crossed for flowers this year. The trees are still quite small even though they now have side branches.
Hi Junglekeeper. Low 50's for sure. Its a Toyostove and displays (in Fahrenheit), but I was probably too grumpy to remember. Had to go out at -45 (in Celsius) to put the heating pad on the fuel filter... I'm sorry, the other thing I can't remember is how old or how big my tree was when it started flowering. But when yours do you're going to be really ,really happy. Carl
If you consider where the trees grow naturally - at very high altitude on windy mtn. tops, sometimes into the cooler regions of SA, maybe you wouldn't be as concerned. They may not want to freeze beyond a light, early frost, but I bet they can take relative cold better than a lot of your other indoor trees.
I thought my plants were dropping leaves because of low temperatures - but now I'm not sure. I have two pots (with about 4 plants in each) and they grew really well last summer - had to transplant them a couple of times - but now the botttom leaves have yellow margins & are dropping. If it's not temperature - what is it? They are both in pretty strong indirect light and the top growth is still healthy & shiny. Any ideas?
fossil, Your description is quite similar to mine upthread. The shedding of leaves near the bottom (and thus the oldest ones) seems to be normal based on my very limited experience with these trees. I'm not concerned as long as they look healthy.
So - it seems dropping leaves are normal. Can I ask another question? One of the plants I have grows tall & skinny - can I pinch or prune to make it bushier or will I kill it? Thanks for the help so far - I have never had one of these plants before & don't know anything about it so any experience is very welcome!
Not sure. I've broken enough branches and twigs to know that it doesn't seem to harm the plant very much, but I don't know if it encourages bushing out. Carl
We have one that is about six feet in our bathroom, we have to cut it every year because it's an indoor plant for now. It is fairly bushy and does not seem to mind the topping... also the only time we have leaf drop in mass quantity is when I forget to water the poor thing:)
The minimum temperature in the room was 3C/37F this past winter. No sign of damage. The CRFG lists the harm and kill temperatures for coffee as 0C/32F and -2C/28F respectively. (Ref: http://www.crfg.org/pubs/fl/C.html)
