General Gardening Question

General Gardening Question

So after the winter we had down here, a lot of the more tropical trees either died outright or died way back. There is a house not far from me with an elderly Vietnamese couple filled with Sugar Apples that took a hit in the frost. The trees have been trimmed way back (from about 10' tall to about 4') and the ends of each trunk wrapped in a clear plastic bag, rubber-banded to trunk. What, exactly, is the purpose of the bags? Is it to accelerate growth? Keep bugs from entering the trunk? I tried to ask the couple, but their English is not that great and I came away more confused than ever. Does anyone know?
Resident bird

Resident bird

Stylish Bargains.

Stylish Bargains.

my room

my room

Spanish Lavender and grass choked roses in California

Spanish Lavender and grass choked roses in California

I has a micro-garden!

I has a micro-garden!

Baking with garden

Baking with garden