This costs a bit but well worth buying if you have wildlife frequenting your garden & eating your plants - an electronic scarecrow.
I don't know if you can buy one where you live as I don't know what part of the world you're in but perhaps if not sold in your area, you can order one online?
It's a monitoring system that has an electronic eye that detects motion. Gentle leaves blowing won't set it off but animal movement will. It's attached to a garden hose that's kept turned on to have a ready supply of water & when it detects motion, it swings its arm (looks like some sprinklers that shoot water afar) to the area where the animal is & shoots a stream of water at it. No harm is done but the animal is startled & scared off. After a while, the animals avoid the area since few like being shot with a stream of water.
This works not just on one animal species, possums in your case, but any animal such as dogs, herons in fish ponds, etc. Well worth it for most. Here's a link for one but before you buy one, look for other companies & check out prices & range of water stream.
www.pestproducts.com/scarecrow.htm