Living in the semi-arid West, the hardest part of planting new trees and shrubs is keeping them consistently and adequately watered. That’s why I turned to tree watering bags—but are water bags for trees good or bad? For me, they save time and effort, especially when planting out of reach of a hose. Though they work well for me, it’s important to know the pros and cons of this ingenious invention to determine whether it’s the best option for you.

What Are Tree Watering Bags and How Do They Function?

Watering bags are sturdy plastic bags with micro-perforations that slowly release water to hydrate a tree or shrub. One of the earliest widely used designs came from a brand called Treegator, which helped popularize the upright, trunk-wrapping style.

These bags typically hold 15 to 20 gallons of water and come in different shapes—upright models that wrap around a single trunk and donut-shaped versions that sit at the base of multi-stemmed shrubs. They slowly release water over five to nine hours, allowing the moisture to soak into the soil instead of running off.

Tree watering bags work well on young trees or shrubs, but can also be used for established ones requiring additional water. For newly planted trees or shrubs, water well after planting, then place the bag around the trunk and secure with the zipper. Shorter profile bags are set on the ground, encircling the tree or shrub. Lift the bag with the handles to spread out the bottom, then fill the bag to the top.

In general, a newly planted tree requires 10 gallons of water per inch of the trunk diameter when measured six inches above the soil. This means a 2 in. diameter. A tree needs at least 20 gallons of water every week. In hot weather or if you planted the tree in sandy soil, give it more. Mark your calendar so you don’t forget to refill the bags.

When you’re done with the watering bags for the season, drain them and tip them upside down to dry before storing them. With proper care, they’ll last for many years.

Pros of Using Tree Watering Bags

When weighing the pros and cons of irrigation bags, it’s clear they can be helpful in the right situations. Tree watering bags work well for many planting needs—here are some instances when they’re a smart choice:

  • Establishing trees and shrubs: New plantings require constant attention and while there’s debate about the best way to water trees, bags provide adequate water without much fuss.
  • Water conservation: Tree watering bags let you know precisely how much water the tree receives, making them one of the most efficient tree hydration methods. Over-watering is just as detrimental as under-watering and also wastes water and money. Plus, they direct water where it’s needed. There’s no point in using a sprinkler that waters the tree and half your lawn if the lawn doesn’t need it.
  • Arid and semi-arid regions: In dry climates, adequate and consistent water reduces stress on newly-planted trees. In semi-arid and arid regions, additional water the following season prevents established trees and shrubs from drying out during months of no rain.
  • Beyond sprinkler zones: Tree watering bags let you plant where there isn’t water. It’s easiest to run a hose to the bag to refill it. But even when out of reach, you can haul water in a tank or buckets to refill the bags.

Common Drawbacks of Tree Irrigation Bags

While tree watering bags have many benefits, it’s important to consider the downsides.

  • Hot water: While useful in dry climates, in Southern regions, the water quickly heats in the sun, and hot water is not good for tree roots. One of the most important tree watering tips is to remove the bags before the heat of summer or fill them in the evening when temperatures are lower. This can vary depending on the seasonal tree care needs.
  • Hiding places for pests: In hot and humid areas, bags that wrap around the trunk create a dark, humid environment, a vector for disease and potential damage to the trunk. Check the area along the tree frequently for signs of damage or disease, along with telltale insects like pill bugs or earwigs that feed on decaying matter.
  • Root ball girdling: Another potential issue with long-term use involves too much water on the root ball, which can cause girdling of the roots. This condition causes the roots to grow in a spiral that ultimately chokes the tree. Use tree watering bags as temporary tools, then focus long-term on soaking the tree at the drip line, the outer extent of the tree canopy.

Alternative Methods for Tree Irrigation

There are several alternative methods to keep your trees hydrated:

  • Drip irrigation uses a system of tubes to slowly deliver water right to the roots. It’s efficient, reduces waste and works well in most climates.
  • Basin or ring watering involves building a shallow ring of soil around the base of the tree to hold water. This method gives moisture time to soak in, especially helpful for young trees.
  • Mulching helps the soil stay moist longer by reducing evaporation. When combined with deep watering, it can be a simple but effective way to support tree health.
  • Subsurface irrigation delivers water underground through buried tubes or pipes. It’s useful in areas where surface water would evaporate too quickly.
  • Clay pot irrigation or olla watering uses unglazed pots buried in the ground that slowly release water near the roots. It’s a traditional method that still works well in dry regions.

FAQ

Are tree watering bags eco-friendly?

While tree watering bags are made of plastic, they promote water conservation by delivering water precisely where needed and reducing runoff. These bags are reusable for many seasons, minimizing waste.

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Author
Amy Grisak
As an avid gardener for decades, freelance writer Amy Grisak uses her experience to encourage and inform readers to delve into their own home-enhancing projects. When she's not building new gardens or trying a different technique in the kitchen, she's on the trails of her Montana home looking for incredible flowers and remarkable views.
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Amy Grisak