My coffee plant is 19″ high by 11″ wide. I repotted it over 6 months ago and it sits near a window facing north. I use a water bulb. The plant has thrived for the last 5 years under these conditions. I allow the water to sit for several days to off-gas the chlorine before filling the bulb. About 2 months ago the leaves developed these dry, brown edges .
Thank you for contacting the Toronto Master Gardeners about your coffee plant (Coffea arabica).
There are several possible reasons for the edges of leaves to turn brown, so this may take a little detective work on your part to identify the problem. Most commonly, it can indicate too much or too little water, not enough humidity, the wrong light level, a build up of fertilizer, or the chemicals (like chlorine) in your tap water.
Thankfully, we can rule out some of these possibilities since your plant has been thriving for years under the same conditions. In general, coffee plants prefer bright indirect light, and at least 50% humidity, so it sounds like you have found a good spot. You also noted that you let your water sit to off-gas the chlorine, so it doesn’t sound like your water is the problem.
So what has changed?
Since you repotted the plant only about 6 months ago, the build up of fertilizer in the soil is unlikely. However, the change in soil could still be causing the problem. According to this Guide to Houseplants, coffee plants like a peat moss based potting mix with horticultural sand added to provide good drainage. Assuming you moved your plant to a larger pot, this could also impact the plant’s water needs since the added soil in a newly potted plant will hold water longer than one that is root-bound. Coffee plants like their soil to be thoroughly moist but not soggy in spring and summer, but barely moist in fall and winter. Check the roots to ensure they are getting sufficient moisture, but are not waterlogged or rotting, as this would actually inhibit the uptake of water.
It is always a good practice to check carefully for signs of pests, too. Good luck and let us know if you continue to have difficulty. Judging by the photo, there is still plenty of healthy growth and your plant should bounce back once you identify the issue.
In addition to the link above about growing coffee plants, you may find the following articles useful.
Why does my houseplant have brown leaf tips and edges?
Beginner’s Guide to Growing Houseplants: A Toronto Master Gardeners Guide