One question came up that I never addressed in my original rain barrel guide - Can you use a regular garden hose to water plants from a rain barrel? Or do you need some special setup like an electric pump?
In case you were wondering: A regular hose works just fine.
I am on flat level ground, and I don't use a pump. I just use gravity. With two layers of cinder blocks and a cement pad my barrels are about 18" / 45cm off the ground. Using a hose that is 75 feet / 22 meters long, it takes about an hour to fully empty the barrel, which is a flow rate of about 0.8 gallons per minute / 3.7 Litres per minute. This is a nice and slow trickle - pretty much perfect for a gentle, slow watering on fruit trees and perennials.
I have a special old hose just for rain barrel water, so no one drinks from it and drinks e. coli. With a couple of hoses it's easy to set up a rain barrel to water trees, and then move the hose every few minutes while I do other chores. If you only need slow, easy watering and you hate hauling buckets around - this setup is perfect.
The only potential downside is that the rain barrel spigots may wear out eventually. The spigot kit I purchased is made of plastic. It works fine for now but we'll see how many years it lasts. Every year I dream about upgrading to a fancy metal spigot instead. One of these years I might save up and treat myself.
Do you use a hose with your rain barrel setup? I'd love to hear about it.