I got a grafted wax apple tree in 2019 and it's been growing slowly the past several years, about 9-10 feet tall now. This year 2022 is the first time it loses leaves in the winter. It didn't lose leaves in the winter before. The person who gave me the grafted wax apple branch told me this kind of wax apple won't start bearing fruits for 11 years. that's what happened to his wax apple tree whom he grafted from.

Could losing leaves be the sign that it will start bearing fruits next year because it's mature now?

No, it's not a sign of fruiting. Jambu is evergreen, but known to be cold-deciduous if it gets too cold in winter. Your tree must have gotten too cold. Usually it will only lose about a third of its leaves. Not all of them. It's supposed to be able to fruit within 3-5 years.

It does not lose all of its leaves yet. about 1/3 so far like you said. Yeah, it's been cold lately.

Are there any good resources on how to take care of wax apple (water, trimming, fertilize ...etc.)? I can't find any out there.

Thanks

I think there is a site for California growers. I know there is a small farm operation in South FLorida that grows these. But largely they have been prohibited from entering the USA for a long time because they harbor the MedFly. So probably not many growers growing them

When is the best time to trim wax apple trees please? And do I follow the same guidelines for trimming fruit trees in general? (remove branches that point inward, criss cross branches, dead branches, top off branches at the top if I want to keep it short)

Thanks