Guava Leaves Turning Black
Answered by: Inge Poot
Question from: Elaine Normandeau
Posted on: July 12, 1999

A few weeks ago I ordered some guava plants from you. I repotted them and kept them inside, watering them regularly. The ends of the leaves started blackening. Just the tips at first but it seems to be spreading. It is the only variety of plant in my house that is displaying these symptoms. What does it mean? Over watering? Not enough? Can’t be too much light, but is it too little? Or is this some disease?

Both the common and the pineapple guava like light, sandy, well-drained soil. A cactus mix would probably be a good commercially available mix for them. They also need full sun.

In my own greenhouse, the guava I grow rooted through the bottom of the yogurt pot I germinated it in into the sand base of our greenhouse and has been hard to keep within bounds with pruning. It fruits every spring and gives us a good feast of fruits. It gets full sun, but through 3 layers of plastic and glass.

I suspect that your plants don’t get enough light and that their roots are not in good condition, causing the leaves to die from the tips from lack of water getting to them. Since the concept of keeping things moist can be so very differently interpreted by different people I would try: watering one plant half as often as before, a second twice as often, transplanting another two into a very sandy mix and keeping that mix evenly moist on one plant and on the dry side for the other and putting all the plants into the sunniest spot you can supply. You can summer them out of doors, but take at least two weeks to gradually expose them to full sun- otherwise all leaves will burn to a crisp.

It can’t hurt to spray all of the plants with a suspension of flower of sulphur just in case it is a fungus attack that is causing the problem- but I don’t think it is!

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