Greenwalks

Gardening where the sidewalk ends

Tree Watering Bags October 24, 2008

The City of Seattle is using some bond initiative money to improve its urban forest – the plan is to plant over 8,000 street trees in the next decade.

One challenge is how to water well while the new trees are being established. In a time of budget crunches, the City just does not have the staff to allow for individual watering of each tree as often as needed to help it thrive.

Starting a year or so ago, I noticed these funny green plasticized cloth bags showing up at the base of each tree newly planted by the City:

Tree watering bag

Each bag, which according to the City’s site holds 20 gallons, is filled several times per week while the tree is establishing its roots. The water seeps into the soil directly where the tree needs it most, slowly draining out over the course of 6-10 hours.

Here’s what it looks like in relation to the full tree, this one a lovely red-bark Japanese maple with its golden fall plumage on nearly-full display:

Japanese maple with tree watering bag

Speaking from personal experience, a new tree in the parking strip is easy to forget about. I put in a very small Japanese snowbell that is not doing well, and I’m sure it’s due to lack of water during the dry season. I know these bags are kind of unsightly but maybe they are a good idea for those out-of-the-way plantings in super dry weather. That said, I have seen a row of trees in a parking strip near my house where some trees seem to be thriving and others are near death. All had the green bags on so presumably they were watered equally. What made the difference? No idea.

Has anyone used these successfully in a home garden? I found one online called the Treegator but it’s not cheap, $25 plus shipping for one bag. That’s a lot more than my Japanese snowbell cost!

For more information from the City of Seattle on watering in newly planted trees, click here.

 

8 Responses to “Tree Watering Bags”

  1. Megan Says:

    I see those around, some were used near my house, where they have been trying to establish new trees in the center strip of a big busy street. They took out big established trees to try to narrow the street, provide parking, and keep a planting strip in the middle, but it’s not working out well. Just when you think one’s established, some car loses control and takes it out. Lack of water has been a factor too over the summer. Those poor trees just don’t have a chance.
    They started with katsuras, and then it seems like they’ve accidentally slipped in some gingko bilobas. No matter, none of them make it very long.

  2. jellyfishbay Says:

    I attended a landscape workshop in August given by a tree specialist for the city of Lansing, Michigan earlier this summer. They use these bags to keep the city trees watered; Michigan State University uses them as well. They are Treegators and the specialist said that the bags could be zipped together to form bigger bags so they could be used around bigger trees with larger trunks. She also said that they would occasionally have to give the bags a tug to be sure that the water holes wouldn’t get clogged up. Perhaps the trees that aren’t doing well are not getting the water as they should.

  3. Racquel Says:

    I’ve never seen those bags before around here. Interesting way to keep newly planted trees thriving during the hottest part of the year. They say you need to water a newly planted tree regularly during the first year it’s in the ground.

  4. deb Says:

    I’ve used the gator bags on newly planted trees. They work fine and don’t waste any water to run off.

  5. Georgia Says:

    Popular in the northeast; I’ve seen them used in Somerville, Mass. and Philadelphia. I would agree with jellyfishbay regarding differences among group of trees with Treegators. It could also be the original quality of tree stock and/or planting technique. Watering newly planted trees is very important in establishing existing roots and growing new ones. You can make your own “treegator” according to GardenWeb (http://forums2.gardenweb.com/forums/load/trees/msg0723500517713.html).

  6. Betty Saenz Says:

    I have seen these in Texas in New Braunfels at Landa Park in Comal County. It is so important to water trees and other plants regularly until they are established. In general, I would say this is a 2 year time frame.

  7. Marijke Says:

    In China they make a kind of dike of clay in a circle around each tree of about 15cm which will hold the rain water near the roots, so they use the in situ earth to keep the tree watered.


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