Tree watering bags are the best thing since sliced bread.

I bought a bunch of 20 gallon bags to put on my baby chestnut trees. Makes watering much less of a chore.

Couple things to note... the bags require support... a 5' sapling isn't stout enough to keep a full bag from toppling over and
damaging the tree. A 5' sapling, grow tube, and 1/2" fiberglass tree stake won't hold a full bag if it isn't setting just right.
I wound up adding a second stake to solve that problem.

The filter bags are a good idea if you're not using hose water. The drip holes are quite small and easy to clog even then.