Easy way to water trees right

Many of the questions I get asked about gardening concern watering -- how to know if a plant's being given too much or too little water, for instance. Inquirers usually want a simple answer -- "once a week" -- but it's often not that simple.

That's why, on my daily walks around Boston, I was excited to see an almost foolproof watering device. One that takes all the guesswork out of watering newly planted trees and shrubs.

A green bag showed up around the base of a young tree across the street from my house, where the city planted a replacement for a street tree that had died the year before. Then I noticed one surrounding another new tree along Mass Ave., not far from my office.

The tag said Treegator, so I came back home to look it up on the Web and find out more. Basically, this bag holds 20 gallons of water -- which you pour in once a week -- and it slowly releases it at the root system of the shrub or tree, right where it's needed.

Brilliant! You don't have to wonder about how much more you should be watering in hot weather or what's going to happen while you're on vacation -- any neighborhood teen can fill it with a hose while you're gone.

There's also a 15-gallon model for smaller uses that's round, flat, and brown -- sorta like a big plastic doughnut. It won't call attention to itself as the taller green model will.

But I have my doubts about using the small one for street trees -- too much temptation to stomp it flat, I suspect. (At least in urban situations such as where I live.)

Reviews on Amazon.com say both models are easy to use. Some people think they're ugly. But to me, one or two aren't bad -- certainly much better than dead trees.

Treegators are made from UV-treated polyethylene reinforced with nylon webbing. You secure the bag to the tree with the heavy duty nylon zippers on each side. You can even zip two of the 20-gallon models together for a larger tree.

It's easy to see why all this appeals to those involved in city beautification efforts. They help cut costs and o doubt ensure a higher level of success.

While I can't recommend Treegators from personal experience, I'll be watching the ones in my neighborhood to see how they perform.